The cost of oil fired central heating per hour

By The Helpful Engineer / On / In Energy Conservation

In our house we have a boost button on our heating control panel. By hitting this button the boiler will come on immediately for one hour only. This got me thinking, how much does this button cost me every time I push it, or putting it another way how much does your home oil boiler cost in fuel to run every hour? Well it is relatively easy to calculate; I worked it out to be €1.20 ($1.64) per hour or €1.20 every push of the boost button!

I calculated this as follows. The typical oil boiler used for home heating injects the fuel into the combustion chamber using a nozzle. Depending on the size of the house/ boiler, this nozzle will vary in size between 0.5 and 0.9 gallons per hour, (at a typical pressure of 10 bar). In an average three or four bed-roomed sub-urban house, the boiler nozzle size is typically 0.6. Converting this to metric, 0.6 gallons per hour is approx. equal to 2.27 Litres per hour. When the boiler is operating, it will burn until the water reaches a set temperature and then it will stop burning until the hot water cools sufficiently. The hot water cools as it is pumped around the house to the radiators which heat the house. The rate at which the water cools will depend on a large number of factors, i.e. whether the house is well insulated, the external temperature, radiator sizes, radiator settings etc. Therefore during cool weather in a well insulated house, the boiler may only actually be burning oil 50% of the time it is operating. But during very cold weather in a poorly insulated house the boiler may well burn oil continuously.

Therefore if we assume that the boiler, when operating, burns oil for 65% of the time, then the amount of oil used is 1.48 Litres per hour (= 2.27L X 0.65). As the current cost of oil, including taxes, is approx. €0.81 per Litre, the approximate average fuel cost of running an oil boiler is €1.20 per hour. This figure is an approximate guide and depends on your house conditions as detailed above as well boiler efficiency etc. The cost has increased in recent times as a result of higher oil prices and green energy taxes and will probably increase further.

58 thoughts on “The cost of oil fired central heating per hour

  1. I don’t know that! I appreciate you giving us a view on what is happening when we push that button. I think people should know this detail so they will know if it’s really fair to have it in a higher cost or is it just a necessity for us to have one. Government should remove the tax since people needs this.

  2. Still confused about this boost button – we have moved into a new build and have 3 boost buttons, 2 for different areas needing heating (living and bedrooms) and one for hot water. A few questions.
    1. Is the boost button dearer in terms of energy consumption that using a timer switch.
    2. If I hit the heat boost button for an hour – will that automatically heat up the water or do I have to hit the hot water boost as well?
    Our bill for 2 months after Christmas came to 270 Euro – we nearly died! DO you know if the ESB nightsave is a good deal – we do use drier and dishwasher a lot!

    1. Hi Meave.
      You are lucky you have zone heating a lot of houses don’t . To answer your questions:
      1. It depends how it’s set up. All a boost button does is turn the heating on for a set length of time. So if you are feeling a bit cool and press the boost button for only one zone that will be better than using your timer to heat all zones. You are saving oil and energy.
      2. It is usually more efficient to heat the water in the tank with the boiler than via electricity. The night saver scheme does save people money as the electricity usage rate is half the day rate but there are extra charges with it for a new meter. Also you will have to run your appliances at night time which might not suit. In my experience it is only really worth it if you have electric storage heaters which you don’t seem to have. To finish normally hitting the boost button will heat your water as well. It does in my house but it depends how your system is set up. You can check this, next time you use the boost button simply feel the tank.
      I hope the above helps.

  3. Hi Help Engineer,

    My query is as follows:

    I have 3 apartments (A,B,C) in a three storey building, all of which are heated by one Oil Fired Boiler located in an outhouse to the rear of the property. At present the heating system in each apartment is operated using an APT manually operated clock. The problem is that if the tenant in either A,B or C does not contribute to the purchase of fuel in the one tank used for all apartments, they can still avail of heat by operating the clock to put the heating system. Whatsmore, tenants who purchase oil for the tank were only purchasing a 15 or 20 litre drum of it as they were afraid of others using it. What was happening was they were constant burning out the boiler motor because there would be an insufficient level in the tank to cause the burner to ignite and cause the heating to come on.

    I want to know what would be my most economic way of controlling the heating system in these apartments.
    The electricity for apartment is operated via smart card- is this type of system via for my oil heating system ? I know Vitalenergi have a system but for to install it into my property i estimate it would be over £3000. Furthermore, if the current cost of filling my current oil tank were to now cost say £1000, and later in the year this was to rise to say £1500, this would have to be reflected in the charge / cost for the tenant/s who wish to avail of
    the heating system. In addition to the smartcard system i would be interest to hearing your views and knowledge on this matter.
    I look forward to your response.

  4. Hello,
    I need advice. I live in upstate NY and I was wondering how much does it cost a year to fill the tank? We are moving intoa home that is fuel oil and I am so scared we wont be able to afford it. My husband thinks it will be fine but I have a gut feeling it wont. How much will it make our electric go up?

    1. Hi Sam. It might be different in New York but here the oil company will deliver what ever you require, within reason. But if you just examine the tank for the capacity and ring the oil company they will be able to tell you how much it will cost to fill or half fill. If the capacity isn’t written on the side of the tank you could measure the outside dimensions and estimate the volume that way.

  5. Some oil companies here in eiré have a scheme goin where u can pay into a card,say 50 a month,20 a week or whatever, we ring em up for a fill or half fill and pay with the card, handy out, worth tryin the companies in your area, they might do the same

  6. We are considering renting an older 4 bed house, ( not actually seen it yet as we are relocating ), as a consideration how much on average is it to use oil fired heating systems ?

    1. Hi Scott. Its very difficult to say as every house and resident is different. I think we spend about the €750 a year. But we have a wood stove as well which reduces the amount of time we use the oil heating. Anyone else want to say what they spend a year on oil?

  7. I have just been questioning the amount we are spending on oil, coal, electric & bottled gas. We are renting a 6 bedroom farm house which was totally gutted and reburbished in 2007. I would assume it has been done correctly and is well insulated. The walls are probably 1.5-2ft thick if the depth of the window sills is anything to go by. It looks like there has been a new skin built inside the old frame. The rooms are all large with large ensuite-bathrooms to every bedroom, a massive 30ft long kitchen-diner & 2 more reception rooms. So far from January this year we have used 5000ltr of heating oil. 30bags of coal. 3 deliveries of logs, 3x15kg gas bottles for a potable heater and on average £130.00 of electricity per MONTH and I am currently sat here with a jacket on! I have had 4 heating engineers out to check the oil burner but none seem to really know the system inside and out and each one comes up with a different faulty part that they replace that could be causing a potential problem. I had 1000ltrs of oil delivered 2 weeks ago and we have nearly used half. And although it has been a wet miserable, cold season up in the highlands of Scotland we have not had the heating on 24/7. Most times we just had the wood burning stove on in the kitchen or lounge wherever we were going to sit as the evening got colder and that wasnt everyday. I am at my wits end with purchasing fuel and cannot get out of the lease for another 12months. Any suggestions?????

    1. Hi Jayne,
      I am a heating engineer and was shocked when I read your tale of woe. It is impossible for me to give you a definitive answer to your problem but safe to say that your oil usage is way way beyond normal even for a poorly insulated stone castle. Can’t imagine what type of cowboy heating engineers inspected your system ! I suggest you firstly leave the heating off for 24 hrs and dip the oil tank to check if there is a leak also be mindful that your oil may be stolen. If no leak or theft please ask a good local plumber to inspect the whole system.

  8. Hi

    This is a very interesting blog as I’m reading currently in bed with two hot water bottles trying to work out if my my boiler is using too much oil or whether it’s an expensive commodity! I’ve used €300.00 of oil in the last 6 weeks. The boiler has only been on 4-5 to hours a day max sometimes less if I’ve been out. After 2 weeks I switched 1 radiator off in a room infrequently used so now I’m only running 4 large rads and I’m turning one more off tomorrow. Will this make a substansial saving? This is an old cottage which seems warm once it heats up but the boiler is a about 12 years old do you think it’s running efficiently? How much should it cost on average for those 3 or 4 rads? I can’t see a thermostat anywhere though….I nearly cried when I saw that you only spent €750 a year. My oil cost is 1.02 cent per litre last time I filled up I also use the fireplace in the large kitchen/ diner and only a woodburning stove seems to be needed in the sitting room.

    Please help!

    Frozen in Ashford

    1. Check with your oil supplier – usually cheaper if you buy 500 litres or more. I can get 500 litres for .86c/litre in Meath.

  9. I dont know if you got my last message, but it was about my boiler using 300 litres of oil since the 21st of november, when it is only on for about 6 hours a day any idea why.

    1. Hi John,

      I am not sure as there are a huge amount of variables. It could be as simple as an oil leak (although I hope not for environmental reasons) to something more complex. The first step would be for you to get a fully qualified oil boiler technician to investigate the problem.

  10. Thank you for your comments.This is the line i was going to take,i dont know enough about boilers to try and do something myself.
    thank you again. Wishing you a happy Christmas,and all the best for 2013

  11. Very interesting –

    Just a question on the conversion of 0.6 Gallons per hour –
    Is the assumption here that all boiler nozzle sizes are quoted in US gallons ?

    0.6 US gallons = 2.27 litres
    0.6 GB gallons = 2.72 litres

    1. Thanks Dan,

      To answer your question, yes oil nozzle sizes in Ireland and the UK are generally quoted in US gallons.


  12. Hi , just 2 questions,
    Does the burner cut off at the thermostat setting thats in the room??
    Does it cost alot to have it starting and stopping 3 times in the day?
    As in starting it up i mean.

    1. Hi Norman,

      For the typical domestic situation the burner in the boiler is usually regulated by the setting dial actually on the boiler. This dial sets the top temperature for the water heated by the boiler. The burner then kicks in when the temperature of the water drops a set amount below the set temperature (as set on the boiler). The thermostat in the room usually just turns the boiler on and off when the temperature drops below the set point (or rises above it).

      The above situation does not apply where zoned heating is provided, which is more complex.

  13. We moved into a 15 year old 4 bed semi dormer bungalow late last year. During the winter we were using 300ltrs of oil a month yet only putting on the heating for 2.5hrs a day as we couldn’t afford to keep it on for longer (we were frozen). Every month we had to top up the tank with another 300ltrs, we have a lock on the tank so know it wasn’t being stolen. Could this usage be due to the age of the boiler, it appears to be as old as the house or would it be possible there could be a leak in the pipe running from the oil tank to the house? Thanks

    1. Just bought a 35 year old 4 bed bungalow. Oil heated. Got a new high efficency condensing boiler to replace the 10yr old firebird heatpac. and an new insulated copper tank.

      My radiators aluminium and have thermostatic valves. The walls were pumped with insulation. Upvc double glazed throughout. Added insulation in attic. lots of variables. I keep doors closed I turn the thermostat down. And we wear heavy jumpers in the house.

      Very hard to figure out where the oil goes. There are honestly a lot of variables and my activity could be wildly different to yours OR our houses could have very different levels of insulation.

      Probably make a small sheet of things you can afford to change ( close doors, wear heavier clothes, etc..) and try that first. Then target something not too expensive like attic insulation and see how that helps.

      Probably lots of small things that together will make a big difference. hope that helps you. I’m happy to compare notes on houses ( It always helps to get more data points )

      1. What size boiler do you have? Are the rads sized for the rooms. You should get a oftec guy to check out your set up. A lot of boilers are over sized. leaking tanks/oil lines ect.

    2. 300ltrs would last me all winter. There must be something going wrong, it might be worth someone coming in to check it out. Mind due a bungalow wouldn’t have any to no insulation or does it. Not that you should be going through 600 ltrs.
      Elaine check my little boilers out, they heat for underfloor heating and hot tubs, and Radiators. The radiators don’t have a lot of water in them so this goes through 1 litre per hour burning between 300-350 degrees F.

  14. Hi,
    I live in an 1 bed apt – an annex of my landlady’s house.
    She is upping the heating bill from €50 to €80 a month. I have no control over the heating as it is fixed at 5 hours per day.
    Do you think this is a reasonable price for heating – 1 bedroom and 1 small kitchen/living space.
    Many thanks

    1. Hi Sara,

      I am not sure as there are a large number of unknowns like insulation levels, drafts, whether this includes hot water, standing charges etc.

      Perhaps the best way forward may be to simple split the overall heating bill on a floor area basis?

  15. Just for anyone’s interest, I decided to check on the cost of oil consumption on my 20 year old boiler. Origionally I fitted a t piece on the oil feed in the garage. If you then fit a clear plastic tube to the upright of the t piece then extended the tube to the ceiling and fix to the wall you have an accurate way of judging how much oil you have in the tank. Take a measurement on the full tank and the same when it’s almost empty It’s best if you fit a valve on the t piece for safety reasons. I fitted a 1 ltr container to the top of this tube and secured it and filled it with exactly 1 litre of oil. After turning the main oil feed off at the tank outlet I started the boiler. The 1 litre then feeds the boiler. It took 23.5 minutes to use one litre. As the boiler turns on and off I fitted an old mains clock across the motor start up and set the hands of the clock to 12.00 o clock. Whenever the boiler started the clock started so it was possible to see the total “on” time so it is then possible to calculate the total cost of heating. Hope this rambling is possible to understand, if not please ask.

  16. I have used 375 litres of oil in 5 weeks.
    Boiler on for 3hrs per day for 4 of the weeks and 5hrs per day Christmas week.
    So it took 120 hrs to burn 375 litres. So my Firebird 90 (14-26Kw) is burning oil at a rate of a little over 3L/hr @ a cost of €0.86/l.
    I have a 1500 sq foot bungalow with
    4 large double rads
    3 large single rads
    3 small double rads
    3 small single rads.
    Costing me about €2.70 per hour to run oil burner.
    Also have open fire in lounge costing about €20/week for coal and briquettes. Along with gas fire in kitchen costing €10/week.
    Total cost of €86 per week not including cost of electricity for immersion etc..

    1. You are correct in saying that your firebird 90 burns 3liters per hour that exactly what my boiler uses I connected a clock to the burner and this tells me
      how many hours the boiler burns each day 500 liters last around 166 hours
      I live alone in a two storey three bedroom house so two of the bedrooms are not used so the rads are switched off.I burn about 14hrs a week just heating the sitting room 1 bedroom the kitchen when Im making dinner the bathroom
      the main thing with oil heating is to have a good digital thermostat installed in the room you use most this will save you a lot of money ok.

  17. hi………. is it cheaper to turn Rads off in unused rooms ? or does it cost same regardless of how many rads are on seeing as it has to heat the water anyway ? …… also, the room where my thermostat is isnt used…….. is it better for me to keep rad on in there to control thermostat ? if i turned rad off in that room would boiler keep burning continuously due to room being cold………… i know its prob silly and obvious questions 😛 but want to double check 🙂 be grateful for any advice . thanks in advance !

  18. I just had a Stanley solid fuel converted to run on oil on basis that keeping the original set up was only efficient if someone kept feeding it 24/7. Without that, the ambient temp in the house would drop and so bringing it back up to a comfortable level required intense fuelling and effort. The house is fully insulated/dble glazed, lagged etc but has no cavity walls, only mass concrete ones which, if they were dry lined would cause massive upheaval and expense as well as making not very large rooms even smaller. That first week of ‘inferno’ setting oil fired heat used what appears to be (no gauge only a visual guess) 250 l ..but the house & contents are all now universally warm. The rads are now off at night and the range temp has been perm turned down by approx 1/2 (except when cooking) . The boiler kicks in fairly infrequently now and despite being 2 degrees C outside, the ambient house temp has not been less than 18 degrees. That’s before switching the rads on in the morning after being off for roughly 12 xhrs. The range itself is left on 24/7 at the moment as it acts like a single big rad and the kitchen door is left open so that heat can disperse through the house (a bungalow) . Whatever is being used now is considerably less..but the ‘inferno’ week has ensured that the fabric of the house, the furnishings, beds etc have absorbed heat. Therefore to feel physically warmer takes only mins as it is only air being heated and not air being heated and then soaked up by house and furnishings (which don’t lose heat easily). It will always cost a decent amount of cash to run & heat the house, but by insulating as much as possible, using some common sense about doors & windows, closing curtains when the outside temp drops (but not obsessive – it is a home after all) Whatever it costs, is therefore going to be as little as it is ever feasible to be. Heating the garden or sky is really what causes any heat source to be over abused.

  19. I have a waste oil heater that is setup outside and pumps boiling water in to a radiator by thermosiphon no pumps needed. The oil I get for free, now it can be used chip oil or engine oil from oil changes in cars. The heater burns 1 litre of waste oil per hour @ 400 degrees fahrenheit. I no for a fact that your heaters can use filtered waste oil in your heaters, has anyone tried it to date? Do check my website out it might be worth a look.
    No buttons to press just runs 24 hours a day 7 days a week.

  20. I have a Grant 90/120 outdoor boiler in the house I am renting. Could you give me any idea how much kerosine per hour it burns? It heats 7 rads (2 small/2med/3 large) and hot water.

  21. Hi Mary,

    Yes you seem to need your oil boiler serviced alright.
    I don’t know any Oil Boiler Technicians in Kerry. But you will need someone trained, experienced and registered. So if you click on the link below (from the OFETC website) you will be able to search County Kerry for trained and registered oil boiler technicians.

    I hope that helps,

    Kind Regards,

    Arthur (THE)

  22. Hi I am spending about £6000 a year on oil. I am living in a large five bedroom house with open chimneys and draughty windows and doors and open up to roof beams! This seems so much. How do I check my oil is ok and I’m not being ripped off?

  23. Hi
    We have a largish bungalow with a potter ton statesman oil boiler. We are spending about £2200 per year on oil, and am thinking of changing to an air source heat pump.

    My question is how do I calculate how much electricity my oil boiler uses, to pump around the water and do whatever else it does to facilitate the oil boiler . Many thanks

  24. I was very interested in David Walkers experiment. Iwould like to know how many rads were on ; how big of an area was being heated; is the house well insuated .Well done David

  25. Hi, I’m currently being asked by landlords to work out how much i owe them for oik heating….There is no meter and the only info I havr been given is that oil was 0.59 pence per litre. If I used one radiator for approx 3hours a day for 8 weeks how do I know how many litres this used?
    Many thanks!

  26. OMG after reading a few of your comments, I’m just amazed at what you people are spending on heating oil a year it just seems absurd. Hold on, power to run the heater too what’s that about. Please why don’t you convert them to burn waste oil and save thousands, has guys with videos that show you how to convert your old expensive burners to burn waste oil heaters, you may need to filter the oil which isn’t a problem, and you must be able to get it free like we can in New Zealand. I burn 1.2 litre an hour at 350 degrees Fahrenheit, this heats one long radiator to 43 C which heats a 3 bedroom home, 2 cats 1 dog and three people two storied too totally FREE. Maybe time for a change guys all the best this winter. Check out my website you might get some new ideas in free home heating. I hope I can help in someway your prices are too high.

  27. …The Run button.. I normally press this to heat house for an hour..but this heats water it cheaper to set timer for jus heating…

  28. Hello,
    Having read through the previous posts. I too am of the thinking there could be something wrong with my boiler efficiency, for the reason, I am burning on average approximately 40litres every 5-6 days with the boiler on 3.5 hours a day… The thermostat is set at 65 C, nozzle is a 0.6 danfoss type, 80% Rads have trv’s. I timed it one day with the boost and it ran for 45mins of the 60mins. The burner is a new reillo 30 from memory.. It’s a 4 bed detached house…. My query was would you be able to calculate boiler efficiency based on the above, as I am guessing that it less than 60% effective or am I way off mark… If you require further information or could tell how to go about doing this calculation, would be greatly appreciated..
    Thanks in advance..


  30. Is it better for me to leave all the radiators on instead of one in my bedroom and one in the kitchen and front room at night when I put the one in the kitchen off.
    I have eight large rads and three small rads.
    I am in the house all day and night. I go through so much oil.

  31. Hello,
    I read your €1.20 per hour with interest – can you tell me how many radiators this was heating?
    I only have two standard size radiators on for most of the day and I’d like to work it per radiator per hour basis,

  32. Hi. This is a great site. Lots of helpful information. This may be of interest to your readers. First let me make clear i am an ex electrician and would recommend if you are going to do this, do not try yourself get a professional. I have wired an ‘hour meter’ to the burner motor feed. This enables me to see an precisely how many hours the burner has run and using the hourly usage scale for the jet, how much it cost ( using local charges for oil). When i last filled tank my calcs said 1000 litres. On delivery we had 996 liters. Keeping data on spreadsheet on phone it enable me to see that in a cold spell in winter, heating was costing £7.85p per day. Scary but at least i was in control and reduce if i wanted

  33. Get It Serviced Annually
    The expert recommendation is to have your system serviced once every twelve months. In fact, this is a legal requirement for landlords. It is not mandatory for those who own their homes, but it is strongly advised. You can, of course, arrange central heating servicing in Suffolk more regularly than this (twice per year), but it should not be less frequently.
    Protection from Carbon Monoxide
    One of the most important reasons for regular servicing is carbon monoxide prevention. When a boiler breaks down, there is a risk of carbon monoxide leaks and the gas is extremely dangerous. It emits no odour, and it is colourless, so it can be very difficult to detect before people in the house get sick. Regular servicing ensures that the boiler and radiators stay in tip top condition and never develop life-threatening faults.
    Proper Care Saves Cash
    It is a false economy to believe that neglecting boiler maintenance is a good way to save money. Not only do regular checks prevent full-on breakdowns (and the need for costly replacements), they also ensure that the system runs at peak efficiency. This is the best way to save cash all year round because you are not wasting money on leaky, poorly performing central heating components.
    Make Servicing a Routine
    When homeowners buy a new boiler, they are advised to start regular services as soon as the unit turns twelve months old. This helps them to get into the habit of performing these maintenance checks and keeping the central heating in peak condition throughout its lifespan. The great thing is that many vendors now offer comprehensive packages. Boiler installation, repairs, and servicing can all be included for a yearly premium.
    Choose a Reliable Company
    Whether you decide to start an annual maintenance schedule or you just want to arrange a single boiler check-up, it is important to pick a reliable provider. Central heating servicing in Suffolk is a valuable service, so look for a company with a superb local reputation. Before you sign any agreements, make sure that all installation and repair work is covered by a quality guarantee. In rare cases, there are problems with new boilers after installation, but a good provider will fix them at no extra cost.

  34. Hello,

    We are currently looking to move out of Dublin. We found a few semi-detached houses which have 3-4 bed and have oil fired central heating. I’m trying to figure out how big bills can I expect.

    Would be in any assistance in the medium isolated house how big bill could be?


  35. HI Everyone,

    I’ve just skimmed all these comments as to peoples alarm at the cost of oil heating – well, for my part, I’m not qualified in anything but have lived in houses heated by oil for about the last 20 years – the answers to all the questions are.

    1. You use much more oil than you expect.
    2. In the winter you will use up to 500 litres a month or more subject to house size – this would be for a 4 bed old house with thick walls.
    3. In the summer, on the other hand, it will be the opposite – so for me, we have probably 5 deliveries from october through to March – actually maybe 6 – from April to Sept probably only 2.
    4. In big old houses which are usually oil fired the problem will always be from the windows, the walls will be thick as you like, the windows prob only 3mm window glass, might as well have them open, I’ve had so many engineers come round who all said the same thing – when its cold you loose loads of heat through the windows – so in an old house no double glazing you prob need to warm the air in each room 4 times per hour – in a house with modern glazing, prob only once per hour.
    5. Big old houses cost big amounts to heat with oil. Its annoying but what’s more annoying, here in UK, is that you also can’t change the glazing often, as in my case, as the house is listed and must be kept like a thermal sieve all its life.
    Hope this helps.

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