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Raypak Heater Fault Code Guide

No one likes to get an error code on any piece of technology, especially on a Raypak heater. It means something is wrong and needs to be addressed soon. The panic really doesn’t set in until you realize error code BD1 means absolutely nothing to you. Error codes are both curses and blessings. Although an error message is never really a good thing, at least it’s an indication of what the problem is. Just imagine how much easier it would be to diagnose diseases if humans came with error codes.) Usually, depending upon the manufacturer, the manufacturer will include a manual detailing what may have triggered the error message and possible solutions to fix the issue. All error code guides are not made equal.

Still, even if the error codes were listed in the manual, what are the odds you know where that manual is? Unless you’re like my mom who keeps all her paperwork in a filing cabinet, the manual was probably tossed a week after your product was working properly. Heaters, though, can be rather tricky without the manual. I love the saying, “hindsight is 20/20,” because it’s so true. How many times did you wish you kept something after you have convinced yourself that you didn’t need it and threw it away? Or maybe it’s just me.

Our goal with this blog is to aid you in identifying and defining the error code on your Raypak heater and to provide possible solutions, as per the manufacturer. If we don’t have a solution or do not address your particular issue, it’s always best to contact Raypak directly.

The majority of Raypak heaters will have a digital readout. The digital readout helps pool owners read error codes on the actual heater. The models with digital thermostats are programmed to display a variety of status and diagnostic messages, depending on the operating conditions.faultpicRAYPAK

They are also equipped with onboard diagnostic controls. If there is a safety fault, a fault code will be displayed along with a service indication. (see pic on right) The word “SERVICE” will flash on and off if the PC board detects a known issue. The fault code is displayed in 3 big letters in the lower left of the display.

Below is a chart we created to help pool owners identify the meaning of Raypak’s fault code. It also includes possible solutions to fix the issue. Keep in mind, this is not a substitute for the installation and operation manual. Should you need further advice or technical information, please give Raypak a call at 805-278-5300.


Fault Code DisplayDefinitionPossible Solutions
BD1Board failure1. If this code appears and stays on, turn off power to board at toggle switch and source, then re-establish power.
2. If code reappears, replace board as the main processor failed to start.
EEPIndicates that memory failed to start on main processor.1. Turn off power at toggle switch and source, then re-establish power.
2. If code reappears, replace board as memory has failed.
FANIndicates the Pilot was lost, or the air pressure switch is not closed when required. 1. Check for correct incoming power at fan relay- 120V or 240V and at fan motor.
2. If pilot is confirmed, check for 24V minimum out of fan relay to pressure switch.
3. If switch does not make when fan is operating, verify the tuning between fan housing and switch is connected and is not kinked.
4. Soft lock out after 3 attempts- automatically resets after 5 minutes.
FFLIndicates a false flame signal. 1. Check to see if pilot is staying lit after CFH is satisfied. If pilot stays lit, the pilot valve in the gas valve is hanging open. Replace gas valve.
2. If gas valve is working properly, problem lies with the pilot system or board. Turn power off at toggle switch.
3. Unplug ignition wire from board and pilot and remove green ground wire from burning tray. Clean and reconnect ground wire.
4. Turn power on. If no spark at ignition module, turn power off and replace the PC board.
4. If you saw a spark at Ignition Module, turn off the power and reconnect wires.
6. Turn power on and unit should fire.
GVCNo power detected at PV or MV when commanded.1. Turn power OFF and disconnect Ignition Wire and Gas Valve wires from board.
2. Power ON and watch for spark at module.
3. If no spark, turn power OFF, and replace board.
4. If spark is observed, turn off power and reconnect wires. The unit should fire.
5. If unit does not fire and code reappears, power OFF, disconnect valve wires from board and remove MV, PV, and ground wires. Clean and reconnect.
7. If unit does not fire, replace the gas valve.
GVOPower found at either PV or MV at the incorrect time.1. Turn power OFF and disconnect Ignition Wire and Gas Valve wires from board.
2. Power ON and watch for spark at module.
8. Low power to transformer can cause a GVO fault.
HL1The high-limit has exceeded 135F1. Possible excessive water temperature in the tube bundle. Once heater cools, high limits resets automatically.
2. Check for blockage in tubes.
3. Check for low water flow.
4. Check Unitherm governor- replace if necessary
5. check bypass assembly- replace spring or bypass if necessary
2. Check for blockage in tubes.
3. Check for low water flow.
4. Check Unitherm governor- replace if necessary
5. check bypass assembly- replace spring or bypass if necessary
IGNIgnition failure1. If the unit fails to hold a flame after 3 attempts, it will go into a hard lockout. Interrupt the power supply to clear the lockout and check for air in the gas line or not enough gas pressure.
2. IGN only appears after pilot has proved and main valve has been powered.
ILOIgnition lockout (Propane units only)1. The heater has performed too many attempts to ignite the main burner and will take a short break.
2. Inspect pilot assembly.
3. If pilot assembly is OK, then the culprit may be your PC board.
PRSLow water pressure1. Check water levels at skimmer face. (should be middle of skimmer face)
2. Ensure pump is running.
3. Check filter pressure. Backwash if necessary.
4. Check heater location- if more than 5 ft above or below water level- adjust pressure switch.
ROLThermal fuse tripped inside heater due to excessive heat or flame roll-out detected.1. Possible downdraft of burner flame. If sensor has red reset button, press button & determine cause.
2. Does your unit need a high wind stack?
3. Check wiring for burns- especially the ground wire and wires at gas valve.
4. Replace wires if necessary.
SNSTemperature sensor is out of acceptable range.1. Water temperature is below 36F or above 110F
2. If the two thermistors are more than 2 degrees apart, the SNS code will appear.
3. Loose or corroded connection at P1.
4. If the sensor is not mounted all the way into the JACO fitting on the header, it may give a false reading.


190 thoughts on “Raypak Heater Fault Code Guide

        1. This is a copy and paste from a couple of other posts asking this same question in the comments below:

          The Raypak manual states this in its troubleshooting section: Pressure switch. Verify water flow and pressure CLEAN FILTER / STRAINER – backwash if necessary

          Make sure your pump is primed and your filter and baskets are clean.

        2. That is the pressure switch. Backwash the filter throughly or clean the cartridges and try it again. It should fire, but may need the pressure switch replaced.

    1. Lisa,

      Charlie covers that in the last portion, it is likely a bad temperature sensor; the sensor is reading it is out of an acceptable range for the heater to operate. Temperature Sensor, IID Units – 009577F

      Recommendations for a fix:
      1. Water temperature is below 36F or above 110F
      3. Loose or corroded connection at P1.

      1. I have a 266A with a “sensor failure” error code. Where are the thermistors located? Are they the same as the hi limit sensors? Is the “sensor” the Temperature Sensor? Are there 2 of them? The display panel does read the water temperature accurately.

  1. Is this easy to change mine just came on to or is this a tech. job if so how long should it take them to change it ?

        1. CFH is a normal code, which stands for “Call For Heat.” The CFH should display right before the SPK (spark) code displays, which means the heater is attempting to ignite.

    1. That is Call For Heat, heater is starting flame rectification process and is in the way to achieve temperature set point indicated – Ricardo Gonzalez – Raypak Training Mgr – Domestic and International

      1. Hi Ricardo –

        First time here…I have a Pentair Easy Touch with a Raypak heater (207A-407A). Everything on the automation end seems to be working. When the set point for the pool or spa is higher than the current water temperature, the LED on the heater turns on as if it is getting ready to fire up. But in both cases, it says “Remote No Demand”. If I take the heater out of remote mode into pool or spa mode, I can get the heater to work every time. Any ideas why is won’t turn on using Pentair Automation?

  2. I’m not getting any codes, but heater runs for only 30 seconds or so, then quits and starts right back up and repeats. Showed up about the same time as a leak appeared. Related? Any ideas? Thanks.

    1. There could be a low water flow issue causing the heater to shut off to protect itself. Or the heater may need to be cleaned, ash and soot can build up in the burner tray suffocating the heater.

    1. I’m going to go ahead and take a wild guess the issue is stemming from a failed sensor. haha

      But to be more specific it is likely a water temperature sensor problem, it is reading the water temp either above 110 degrees F or below 36 degrees F. Usually, the sensor failure error code is SNS. the temp sensor for that unit is part number 009577F.

    1. This is actually mentioned in the blog:

      ROL – Thermal fuse tripped inside heater due to excessive heat or flame roll-out detected.
      2. Does your unit need a high wind stack?
      4. Replace wires if necessary.

  3. mi calentador no es digital es modelo p-d106a-ap-c, el probema con el es que no calienta como al principio solo deja el agua a baja temperatura, cual es el problema ,revise el interior y no tiene oyin que lo sofoque

  4. Hi. I have a raypak p-r406a-ep-c propane heater. It is flashing CFH. I turned off the power for 90 seconds and restarted. It will try to spark (spk) but nothing happens. Then goes back to CFH. Thanks for any help.

  5. I have a raypak p-r266a-en-c ever since I replaced the pilot assembly after I turn it on it sparks then pilot lights then CFH the burners all light with strong blue flame then quickly shuts off. It then repeats this cycle for unto 60 minutes before the burners stay lit. do you thinks I got a bad pilot assembly or is there another sensor that is keeping the burners from staying lit.

  6. I have a Rheem M366A that is displaying, Flame w/o CFH. I just finished rebuilding the burner box and replaced some burner tubes. The heater has worked fine for a month and now shows this on the display.

    1. According to Raypak, it could be a bad board/control module. And in very rare instances, it could be that the gas valve is being over-pressured keeping the pilot light lit when it shouldn’t be.

  7. I have a Raypac model8350 led reading LP , heater was working fine had tech by to check my pool temp sensor going to my pentair touch unit he told my wife sensor was fine even though it was reading 104 degrees in the pool that was actually 88 . Said one of the wires in touch unit was rusty and cleaned it and the temp then read 63 10 minutes after he left heater stopped giving heated water , 4 hrs later got the codeLP

    1. According to Raypak’s manual the LP & LP3 error code means the following: “Shortage of refrigerant gas in the unit or faulty low-pressure control. The unit will show (LP3) after 3 LP faults and shuts down the unit and pool pump for protection. If this occurs, you should call for service.”

  8. I have PRS code clean filter heater won’t start. I already backwash filter, pressure now normal but heater still won’t start showing the same error

    1. Pressure Switch. Filter is clean that’s good. Pressure Switch is at fault.
      Call a technician. After replacement new switch must be adjusted precisely.

      1. I have the same model PR405BL and same message…When I flip the switch it reads RV 0, then CFH, then SPK as well as showing a pic of the flame and the spa temp that I set it to. (104) It clicks once and that’s it. I don’t smell any gas and nothing else happens.
        I cleaned out everything on the heater as well as backwashed and cleaned the filter.

        Any suggestions on why it won’t start and how to fix this issue?

  9. I get a Sw open default. The manual states it is a Water Pressure switch open.
    Now what? Can’t find what to do about it in the manual.



    1. Hello Pooldok, are you sure that is the correct code and model number? I searched PA6 in a few manuals and come up with nothing. Also, the model number ending of “G” is not a usual number, it should be a “C.”

  10. Ignition failure Raypak 266,000 btu.
    I hear clicking but no ignition, could this be a bad ignitor? Heater is 2013

    1. Best guess: The burner near the ignitor might be clogged. If you hear the ignitor attempting to spark but there is no flame, there might not be enough gas or air to make for proper combustion. That is something you should have a professional come out and take a look at, for safety reasons.

  11. I have a LoNox Tab Fault in my Raypak P-R406A-EN-X. I already reset factory defaults and cleared fault codes, but error keeps reappearing. Low Nox Tab is not broken and I know the manual says that “If TAB is NOT broken and the board detects power at Lo NOx connector, Lo NOx Tab Fault is displayed and the heater will not operate”. Manual does not say how to fix this. How do I fix this/make sure board does not detect power?

  12. I have a customer with a raypak heater that has a code that says either water supply or water switch open. Is that a pressure switch problem? It hasbeen backwashed and put on recirculate to test unit.

  13. Raypak heater turns on, when turning on the heater after winter it just sparks and doesn’t ignite…please advise.

  14. Matt,
    Raypak 336A gas heater. Unit in service for 10 years. Getting code “no pilot sensed ignition failure.” Pilot sparks for minute or two like it wants to light but will not and I get the code and pilot continues to spark. Any ideas for me? Low/no gas supply from clog maybe? Yes, there’s gas in the car (gas supply turned on).

  15. I have a Raypak 406A pool heater. After ignition and flame an “low voltage” error displays on digital panel for the duration of operation. No explanation in manual.

    1. What is the code that is being shown on the display? The code will only be three letters long.

      Going by the 36-degree reading, and the time of year I would say something is wrong with a temperature sensor. But that is a guess until we get more info.

      1. I don’t get a code ether
        My unit is set for 85* but as the unit is heating it stops at 81* and flashes internal fault and won’t heat any more
        just had mother board replaced this summer

  16. I have a Raypak 336A and I am getting a CLK message. I don’t know if it is wired through the pump timer but the pump is running.

  17. The CLK fault code means “Clock – Time Clock. Heater is off by programmed control of a Time Clock.” Is your heater controlled by an automation system like an InteliTouch or Aqualink

  18. I have Raypak (Rheem) 266A that is nine years old and I have my manual but it does not show fault code TA6, can you help?

  19. Hi I have a raypak model p- m206a-en-x . I had error code of sensor had burnt wires and repair turned on and it ran . Then turned on in morning and unit would run and then error of ta6 and fan codes are coming up? Any ideas of what to look for? Thanks

  20. I have a Rheem Electric Heat Pump M8350TI-E. It reads DEL. What does that mean and how can I fix this issue. The unit won’t operate. Thank you for your help.

    1. I have looked everywhere, and I cannot find that code. I have looked for Rheem and Raypak manuals and they have nothing on this code. It is very strange. You may need to call Raypak.

      Honestly, if this was a slower part of the season I would give a call myself, but the pool season is in full swing for me. If you get an answer, please post an update.

  21. My Raypak control board is reading VNT and SERVICE in top right corner? I believe this means there is an issue with the Vent switch but not sure how serious this is?

    1. VNT code means the vent switch is open. The manual does not show too much information about it. They only state to turn off the heater at the breaker, turn off the gas and power; then call a technician.

  22. I have an RP2100 works fine but the temperature setting went to 104 and I can’t adjust it down. Heater seems to work fine, I have to turn it off when it reaches desired temperature. Do you have any idea which part or parts could be bad?

    1. I’m not a heater tech, but that sounds like you have an issue with the hi limit switch or the thermister. You probably want to give a call to the manufacturer just for a quick troubleshoot.

  23. Hi Matthew, I have a raypak 266A pool heater with no error codes. It makes a squealing noise when heating. Not at first, but 30 seconds after ignition. What are your thoughts on this?

    1. There may be a deformation of one of the gas orifices or the gas line causing the squealing noise. Kind of like when you purse your lips to whistle.

      To check the line, you need to get a professional out there to take a look.

  24. I have a Raypak 2100 unit which is 12 years old , I have replaced the control board but it would seem that the first problem was the switch on the side.
    So I finally have a code R1/ 1 exactly like that , what does that mean it then shows the water temp but off and I cannot change the state.
    can anyone help

  25. Mr Simmons, thanks for all the info; you’re a huge help. I have an issue with my Raypak pool heater (r206a) and hoping you can help. Unit lights fine, gas burns evenly: However when the unit gas feed “steps up”, it kicks in a horrible jack hammer like sound, like it’s trying to ignite gas that’s already burning. And it’s not every time, it’s sporadic. I get no error code, system just says heating. At a loss on this one. Thanks!

      1. Everything I have read leads me to think it is a water flow issue. the jackhammer or knocking sound could water boiling inside the exchanger. Obviously, not good. This may be caused by scale, bad bypass valve, pipe blockage. Because I am not a licensed tech, I couldn’t tell you safely check your heater, so I suggest calling a service tech.

        By the way, cool name.

        1. Yes! Great name, ha ha. Just a follow up. The sound emanates from the gas valve itself. I’ve seen all kinds of weird valve issues in my life but this is a new one. Anyway, thanks for the response. I should have went with hayward, ha ha.

  26. I have a gas Raypak RP2100 R265 that is about 10 years old. I recently replaced the heat exchanger with no issues. I go to turn the heater on and there is no reading on the digital display and the unit does not spark and light. It appears as if there is no electricity to the unit. Are there fuses on these heaters?

    1. When you turn on the heater, does the breaker flip? Do you hear any noises like clips or hisses?

      The only fuse I see is the Thermal Fuse, part # 005899F. According to the manual, “This is a “single-use” type fusible link or thermal fuse, that must be replaced when disabled by an over temperature condition, caused by excessive restriction in the heat exchanger flue passage.”

  27. Hi
    My electric heater immediate flashes off when the breaker is turned on. When I try to turn up the temperature, it either flashes r25 or lets me click it up to desired temp but then goes back down by itself. It is sporadically working. It is model R410A

    1. R410A is the standard type of freon used in air conditioners and heat pumps, it is not a model number.

      Also, because it is a heat pump, the codes will likely be different than the ones for a gas heater.

  28. My heater says revision 1.03 when I turn it on. Does not ignite or give any other code. I can’t find this code anywhere. raypak heater digital panel purchased 2015. Model number M266A

    1. That seems more like a firmware version instead of a code. if there is no code, no code and the heater still isn’t firing, you may want to try calling the manufacturer for their suggestion or having someone onsite to inspect the heater.

  29. Hello,

    I am having a problem with my Raypac 206. The temperature was reading 207 degrees (No Demand), but obviously the spa was not 207 as it was more like 50 degrees. So I thought it was the Sensor and so I replaced it…. no changes…. so I thought it was the circuit board…so I replaced it…. no change….

    Anyone know what could be the issue?

    1. Chris, at this point you have replaced the two things I would have suggested. I think it is time to stop guessing and have a technician look at it in-person. There comes a point, where guessing what the issue is is costing you more than what hiring a technician in the first place would have cost.

  30. i have a raypak pool gas fired with a code w/o cfh and the ignighter not turning on ive never seen this code before been a tech for 20 plus years has me stumped must come to conclusion

    1. This is the only code I could find with the “w/o” in it:

      Flame w/o CFH – Pilot flame detected with no Heat Demand. Control Remains locked out until flame is not present. Gas valve (pilot) may be stuck open.

      1. what does that mean though? And how can i fix it?!? I’m getting that same ‘flame w/o CFH’ error. I’ve read numerous places the same description you quoted, but no answer as to what exactly that means or how i’m supposed to fix the issue?!? Is it dangerous if the pilot is stuck open? If so or if not, how can i fix it, or do i need professional help? Mine happened when i turned the heater on and then shut the pump off for a second. I quickly contacted my pool builder, he suggested shutting it off for 20 minutes and trying again, but i left i about an hour and still no good?!?

        1. It’s dangerous if you do not know what you are doing. Get a professional to take a look at your heater. Pool heaters with open gas lines, faulty equipment, and a novice poking around can lead to an accident.

    1. The PLT fault code on Raypaks is acknowledging a pilot failure. This can be fixed by replacing the pilot, or you need to clean the orifices and burners. Call a local service company to come inspect and correct the issue.

  31. I have a rollout switch open code on my heater model number cr-406a-en-c
    I understand this is a flame issue and am wondering if there is a possible reset I can do to see if the message goes away. We live in Las Vegas and it gets quite windy here and wondering if maybe that caused the issue.

  32. There doesn’t seem to be a reset button unless it is under the cover where you turn the valve on and off but it seems to take a security torx fitting to remove it. Thanks


  34. Matt, I have a Raypak R206A pool heater that is giving me a message that reads 6 minute ignition delay, what should I look at first ?

    The heater does fire up but stops after a couple of minutes….

    1. What is the actual code that reads on your display? Generally, Raypak’s codes are 3 letters long.

      Also, when the heater does finally ignite is there a loud bang or “whoosh” sound? Before the heater stops, is there a knocking sound or hissing?

  35. We have a model Raypak 406-A unit with a new curcuit board recently installed about 3 months ago. We needed to break the the Low Nox circuit tab as it is not a Low Box unit. We actually forgot to break it when we first out it in and then realized we forgot to break the tab and got the TA6 Tab error code.

    It had worked flawlessly since we installed it.

    The old board (circa 2006) had a CLK error that we couldn’t clear likely to a degradation of the circuit. It also had the NOX tab broken.

    Anyway, yesterday we went to fire the heater (after using it several times in the past week) and now have the TA6 (Tab) alarm.

    Any idea what to try?

  36. OK, so we have figured out a workaround, let me know if this is safe. I unplugged the P-10 air switch terminal wire on the board that is right beside the Low NOx tab (broken off), started the unit and it fired. It then ran for about 30 seconds and shutoff with a FAN error code. I started it again and this time after it started, I plugged in the P-10 air switch wire and it continues to run. Do you see any safety issues with this?

  37. So it turns out that now when I start it with everything back normal, the heater fires without issue. It looks to me like it is a glitch in the firmware code of the circuit that can’t be cleared until the heater fires properly again. I had cleared all faults and set to default earlier but not until I unplugged the P-10 wire and then plugged it back in after it started did the error code for TA6 no longer appear. I wouldn’t just throw away the board if you get that error with a Low NOx unit, try the steps that I did and see if it can work for you as well.

  38. One more thing, if you cycle the power to the board, the TA6 error returns and I have to unplug the P10 wire, fire the heater, then after it starts plug the P10 wire in again. It will start after you shut off the heater until the next power cycle.

  39. Thanks for the reply, totally understand the late response during Holidays, Happy New Year! Our Holidays were much happier with a hot spa😀

  40. Last one…so we have cycled the power at least 3 times recently and the heater has fired without issue. No more TA6 errors. I have put the screws in the panel to keep the board in place and we are enjoying hot water on demand remotely.

  41. I am having an issue with my pool heater.
    Raypak model number C-R206A-EN-C ASME.
    It sparks, fires up and runs for about 10 seconds, then it says “no demand” and “SW Open”. It is about 10 degrees outside, so I am wondering if it is just too cold? The heater is in a room with the other pool equipment, but it is very cold in there. Please help

    1. Those readings are likely a bad pressure switch or temp sensor. But those codes could also be a byproduct of the temperature. Pool heaters are not meant to run in temp that cold.

      Because it is a commercial install (ASME) heater you should probably call Raypak directly to get a confirmation.

    1. This is what the manual says about the Roll Out SW Open:

      Roll Out Sw Open – Rollout Switch – verify gas pressure, combustion air, blocked heat exchanger, proper vent size/connections, high wind conditions.

      Have you or a technician checked these causes?

  42. Mathew,
    The sun baked out my display on a Raypak 010253F circuit board ( I have Raypak heater 406a-EP-X-010213), I put on a new LED display fired up the heater and I can only toggle between “Remote No Demand” and “Off Water Temp”. I pushed the reset button to bring it back to factory settings, and when pressing the up/down arrows, it doesn’t go to “Defaults Set”. It appears my navigation is severly limited when pressing to the up/down and mode button. I’m thinking may the board is bad since it doesn’t allow me to move around the settings. Your thoughts?

  43. The sun baked out my display on a Raypak 010253F circuit board ****LED*** (See previous post) So I put on a new LED Raypak 013640F……

    1. I received the below reply from my contact over at Raypak:

      With respect to the problem on the 010253F PC board, it sounds like the customer had accidentally put the heater into remote mode- prior to replacing the LCD display. In order for the touchpad to operate, they must take the heater back out of remote mode- by holding down the UP and DOWN buttons for 3 seconds. This will take the heater out of remote mode, thereby enabling the touch pad.

  44. I have a Raypak Heat Pump Pool Heater, Model # R6350TI-E giving a flashing PSd code when powered up. Cant find this code anywhere in the manual.

  45. Try to heat the Spa, supply and suck water to and from Spa only. The water level goes down and temperature not increase. Any suggestion? Raypak model R8350ti-e flash with FL3

    1. Going by the description of the problem, it does not seem like a problem with your heat pump, but something is up with your pump/plumbing. Below is the list of things the manual says it could be:

      Possible causes:
      • The filter is in backwash position.
      • The filter pump is stopped.
      • The filter is dirty.
      • Shortage of water to pool pump.
      • FIL parameter must be set to activate pool pump.
      • Water pressure switch must be adjusted or it is broken.
      • The unit is in the protection mode and will show (FL3), press any key to restart the unit.
      FL3 code will stop the unit and pool pump.

  46. Hi I have a RAYPAK 406a I got a code of rol Is there any way to reset this or bypass Or what do I need to fix this problem

  47. I have a ream pool heater that works for about an hour then goes to spark and call for heat continuously until it Burns out the roll out

  48. I have a Raypac RP2100 heater. I was getting a error code of INT (the display is hard to read), the service light then flashes and heater will not start. I had a guy come out and said the high tension wire was loose. It then worked. About a week later it did the same thing and did not start. I had the guy come out again and it started right up for him. The display shows the CFH and SPK codes, temperature, as it should. What is wrong, any ideas for this random problem?

    1. Call For Heat (CFH) and Spark (SPK) are normal codes when the heater is initiating its start-up procedure.

      TThe closest code I can think of that resembles INT, is VNT which is Vent Switch Open. Raypak state to turn off the heater at the breaker, turn off the gas and power; then call a technician.

  49. Our heater stopped working last night. When we turn it on, the RV1 code comes on, then switches to the Temperature of the Pool on the left, and Set Point of the Pool on the right. The code then switches from the temperature of the pool to the CFH code with “Clean Filters/Strainer” above it. We did a backwash and cleaned all the strainers in the pool. The code then switches from CFH to PRS with the “Service” blinking above the set point temperature. We check there is water going into the water heater and nothing has changed for the past 2 years. Pilot flame is not lit and no clicking is heard when we start it up. What do you think the problem could be?

    1. If you check your filter’s pressure gauge, is it reading the normal PSI as before when the heater was working? The issue seems like that water pressure switch is not receiving enough pressure to give the ok for your heater to ignite. That can be either a real flow issue, or you need to replace the pressure switch.

      To troubleshoot it further, I suggest you call Raypak. They are really helpful when it comes to troubleshooting these types of problems.

    1. This is a reply I received from a Raypak tech regarding your Remote no Demand code:

      It means that the heater is in “Remote Mode” and the water temperature is at or above the setpoint temperature selected on the controller. First of all, is the heater connected to a remote controller?

      If not, then the customer may have accidentally put the heater into remote mode -by depressing the up and down arrows for three seconds or more. If this seems to be the case, they do the same thing to exit remote mode. If this continues to occur, then the buttons on the touchpad may be stuck, in which case they would need to change the touchpad (decal membrane switch). Hope this helps. Please feel free to give me a call to discuss further.

    1. I believe it is the Temperature Sensor, IID Units – 009577F. The parts diagram for the ehater can be found here: Raypak Atmospheric Digital Heaters 206A-406A (11/01/04-Current) As shown in the article, the things to check:

      1. Water temperature is below 36F or above 110F
      3. Loose or corroded connection at P1.

  50. Hi,
    I have a Raypak R406A that I have inherited when I bought this house. Since I moved in, it has displayed HL2 after running for a little while (hour or two). If I bump it up only a couple of degrees at a time, it will take longer to display HL2 but it will inevitably get there every time I use the heater. The hottest I have seen the temperature get befire displaying HL2 is about 92 degrees but I have triggered the HL2 in the 80s as well.

    I already replaced the internal bypass kit which was toast, the temperature sensor which was still working but the thermowell was in bad shape, and the 2nd limit switch.

    Ran an inspection camera down the tubes and they do not appear to be bad condition or have much buildup at all.

    I took apart all of the jandy valves and they are all clear from obstructions.

    I am out of ideas here. Please help.

    1. Hello MD – I sent your question to a Raypak tech that works with Inyo, and he provided the following answer:

      HL1 or HL2 is an indication that the heater shut off via one of the auto-reset 135-degree high limit switches in the safety circuit. These redundant switches monitor the temperature of the water in the inlet/outlet header.

      When the water exceeds 135 degrees, one of the high limits will shut the heater down and either HL1 or HL2 will appear on the display. Assuming that the pump is running, the water inside the header will cool down and the high limits will reset- allowing the heater to fire up again- until the point where the water in the header exceeds 135 degrees and the process will repeat. This is typically referred to as “cycling on the limits”.

      This is most often caused by insufficient water flow velocity through the tubes of the heat exchanger. Causes can include: restriction in the tubes (scale buildup), corroded bypass, eroded bypass spring, corroded Unitherm Governor, restriction in water flow to the heater, or back pressure after the heater.

      If the HL2, in this case, is resetting and allowing the heater to fire after cooldown, then the switch is fine. If it does not reset after cooldown, then replace the high limit switch.

      1. Thank you for your quick reply Matthew. I already replaced the 2nd high limit switch (assuming this is the switch that is closest to the right). I also replaced the U.G. and the internal bypass spring which was corroded. There did not appear to be any build up in the heat exchanger tubes.

        The heater does cool down and produce hot water again but then the HL2 code returns after a while again. Is this safe to keep running this way?

  51. Hi… At my job, we have a model P2005-A and the error code is DELTA T. What does this mean? I’ve looked through all the recent messages and haven’t found anything similar. Can you help please?

    1. That model looks to be a commercial boiler and not a pool heater we are referring to in the article. Your best bet would be to contact Raypak directly.

      A simple search in google brought up an owner’s manual with all the codes for me. A little search goes a long way.

      “Delta T – Captures the highest Delta T Temperature recorded. Press UP & DOWN buttons for 3 sec to clear this entry”

  52. Rheem natural gas pool heater model P-M267AEN-C throwing code PR5 and message “CLEAN FILTER STRAINER” with “Service” in smaller letters on top right hand side of display. According to your code reference it may be a clogged pool filter needing backwash. Are there any filters inside the heater I also need to pay attention to?

    Thank you.

    1. The heater does not have filters that need cleaning. The PRS code is referring to low water pressure. If your pump strainer is clogged or your filter media is dirty, the water flow could lower below the heater’s minimum water requirement. If you have a variable speed pump, sometimes this will flash if your pump drops to lower RPMs.

  53. Hi
    I”ve got a RP2100, it’s worked fine for about 10 years, in the last week it will only heat up to about 85 deg. I’ve got the temp set for 102. It turns on fine SPK comes on and ignites runs with no error codes after about 15 minutes it will show SPK on display and reignite and run for about 10 more minutes then it repeats that and only gets to about 80some degrees. where should I look for the problem, no error codes.

    1. One of our close Raypak techs said to check for any loose wires/crimps in the wire harness. Also, check the wired going into the connector that plugs into the PC Board. Sounds as if it could be momentarily losing contact.

  54. i have a raypak tankless and when i run water it flashes 11 and beeps when my temp should be 120 any ideas whats wrong here?

    1. Is this Raypak unit you are working on a pool heater or a tankless water heater? I can help you with the pool heater, but I would need to know the model number of the pool heater.

      If you are referencing a house water heater, you would have to contact Raypak or a boiler technician company.

  55. Hi Matthew
    i have just purchased a new raypak M206A Pool heater and i shipped it to Thailand.
    Can you tell me what the input gas normal operating pressure should be.

  56. Hello Matthew!
    We have a Raypak M336A, and the tech came out on Monday to turn the pool on for the season. He checked the heater and it fired up right right away. But now it won’t ignite, it just sparks. It’s throwing the HL1 and GVO codes. Any help would be appreciated, Thanks!

    1. Andres, those codes and what are causing them are listed in the article. Have a tech come out to correct the issue if you do not think you can check the systems that are mentioned in the recommended actions.

  57. I work at a rental property and they have a pool&spa area. I have two ray pac units that are giving me problems they both go into pro5 codes and say clean both pumps straners and i take them out and clean them which they both have nothing in restart them both they light and run for 2 minutes they both shut down and relight again but they both go into pro5 codes saying clean straners again but nothing in them . What can i do.

    1. What is the model number of the heater? The residential models only flash 3-letter codes. Do you mean it was a PRS (pressure switch open)? If so, thoroughly backwash or clean the filter; if that doesn’t work then you’ll likely have to replace pressure switch.

  58. I have Raypac C-R406A-EN-C. When it turns on it calls for heat, says spark, the pilot lights, then opens gas for the burner and burns for 3 seconds says heating, the burner turns off then calls for spark again. This continues cycling off and on, yet is does not stay burning. I have checked all sensors and none are bad. Help please.

  59. Hello, I have a raypak p-r336a-ep-c. The unit was already installed when I bought the home and come to find out it does not work. I going the transformer was bad and not supplying voltage to the PCB. Installed a new transformer in the unit and now I have power to the PCB and the LCD backlight turns on but there is nothing displayed. Do you think i need a new PCB or just the display? Is there any way to tell if the PCB is working? Also the unit had some burned up wiring down to the ignitor that I fixed as well is this something that happens with these units. Thanks a bunch.

    1. Most likely took out the sacrificial 5 amp fuse on the PCB- located next to the P6 terminal. This fuse protects the board from being shorted out. Its easily found at hardware or auto parts stores, or can be ordered under part #013733F.

      The igniter’s high tension wire is not one that is typically able to be repaired. It could have either been melted or chewed by rodents. The high tension lead is part of the igniter #002003F and should be replaced. I would also inspect all other wiring in the unit prior to replacing the 5 amp fuse and powering up the heater.

      1. Thank you for the reply. The fuse is not blown and there is no other damage with the wiring that hasn’t been fixed. The LCD backlight lights up but there is no actual display. Is there any way to determine if the LCD is just not working and the PCB is? Thanks again.

        1. Okay, good. Could be just the display, but the heater should work. Problem is that, without the display, we don’t know what mode we are in and where the set points are. Try and press the mode button once and press the red up button a few times. If you hear a click and a spark, then the display is bad and the PCB is good. The display is replaceable, by removing the PCB and squeezing the two tabs on the back that hold the display to the board. If indeed this is the case, I can have one sent to you.

  60. Hi Matthew, just installed a Raypak 156a pool heater. Getting a sensor failure code. The unit is brand new but sat in garage for a year waiting for gas line install. Was unboxed and hooked up but won’t fire. Looking for initial install startup guide or checklist. Can’t imagine what’s wrong or where to start troubleshooting.

  61. Ok I’ll start there. Are there any detailed instructions or diagrams as to accessing the sensor and wire? I have taken off the front cover but do not know where to go from there. What is the easiest way to access the sensor and wires you think are damaged? Remove the upper panel where the digital display is? Or a side panel? Or is it in the rear? I’m fairly handy but don’t want to pull things apart that don’t need to be. Thanks!

    1. Ok Matthew it was a lose connection at the sensor in the rear. I now have SPARK appearing on the display but it isn’t lighting. I only let it try for about 30 seconds at best. I wasn’t sure how long on initial unit startup (zero use so far, new install) it should take to fire the heater.

      1. So I let it attempt to light for several minutes and now get the error code Ignition Failure, no pilot sensed. Gas appears to be on, could it be a low gas flow issue? Lines are new, could I possibly make an adjustment to the gas valve to allow more flow?

    2. The sensor is located on the inlet side of the inlet/outlet header (where water enters the heater), in a white compression fitting. You will need to remove the side access panel above the inlet/outlet, then follow the wires as they lead to the main control panel. To access the control panel, the front door needs to be removed as does the two screws on each side of the control panel. The panel will then hinge down exposing the PC board. The temp sensor wires plug into the board near the bottom RH side.

      1. Thanks for the info. See my messages above, as I have resolved the sensor issue but have a new issue. Could the gas be too low?

  62. Getting an “ILO” error. Are there any troubleshooting tips to address this or do I just need to call a tech?

    1. ILO is ignition lockout. If this is a propane heater, they have a 90-second lockout that is required by code. Basically, the pilot is not proving within 90 seconds. You should be able to turn the heater off and back on and it should begin the spark process again. Also, confirm that the tank has gas. If that doesn’t work, then a tech will need to look for the cause. Hope this helps.

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