System Fluid Fix

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Here in Fairbanks, AK, October brings sub-zero temps, and the college kids like to take photos in their underwear in front of the University of Alaska Fairbanks temperature sign when it gets into the -40s. We average almost 14,000 heating degree days each year. The difference between a functional heating system and a non-functional one can mean frozen pipes in less than an hour.

In the 1970s and ’80s, the oil pipeline boom came to Fairbanks, bringing with it an influx of new residential construction. Thousands of homes were built quickly, many with in-slab radiant and oil boilers. In the past decade, we’ve discovered that these systems include non-oxygen barrier tubing, which is murder on pumps and boilers. Sludge was so thick in some pipes that flow ceased entirely, and when drained, system fluid looked like mud.

What we did in the past was isolate the new near-boiler piping with a heat exchanger. That way, the boiler and other new components were free of the corrosion that oxygen-rich water creates. We’ve since found another solution, and one that comes at a substantially lower cost to the homeowner by eliminating the heat exchanger.

One of the jars is treated with inhibitor, and the fittings look warehouse-new. The fittings in the other jar though … well you can’t really see them through the muddy goo.


In late 2012, we learned about water treatment products made by Fernox that have proven to stop or minimize corrosion even in the presence of oxygen. Other companies, like Rhomar Water, make similar products, we just began using Fernox.

We primarily use the Express Cleaner (F5) and the Express Inhibitor (F1). (They call it “express” because of how quickly it’s applied.) After seeing how effective they are, we started suggesting it for every hydronic job: new, retrofit, or service.

As a matter of fact, I have a pair of ball jars on my desk full of fittings and tap water. One of the jars is treated with inhibitor, and the fittings look warehouse-new. The fittings in the other jar though … well you can’t really see them through the muddy goo.

How we use it

The treatment is a two-step process; clean and protect. Together, it’s an inexpensive insurance policy for our customers. Both the cleaner and inhibitor come in a pint-sized aerosol can that has a hose connection for the boiler drain. You screw the can to the system, open the valve and inject the liquid. It takes about 10 seconds total.

Inside the can, the liquid is in a bladder, so you’re not actually forcing any gas into the hydronic system, just liquid.

We inject the cleaner a few days before we plan to drain a system, though the instructions say a few hours will suffice. The dirt that comes out afterwards is staggering. After we refill it, we apply the inhibitor, and test the water with our protector test kit to make sure we’ve added enough. From that point on, we

check the inhibitor level once a year and re-apply just the inhibitor if needed.

Because there’s no time involved in the process, we don’t actually charge labor for using the liquids. We just charge for the product itself. It’s an added service that I can feel very good about.

We sell the Fernox products based on a system maintenance and longevity advantage, but the manufacturer has done tests that have proven a 15% efficiency increase when the cleaner and inhibitor are coupled with their magnetic TF1 Filter.

Because severity of our winter fluctuates so greatly from year to year here in Fairbanks, it’s nearly impossible to make any attempt at tracking fuel savings. In our opinion, the maintenance advantage alone is well worth the minimal cost.

Fernox sells the F1 and F5 products individually, or as a kit that includes both as well as a test kit that indicate dilution ratio of the chemical in the system fluid. That said, it’s impossible to over treat with either product. You can’t do any harm to metal, plastic or rubber components by adding more than you need.

Each can treats roughly 26 gallons. When we’re working on a big system, we’ll use two cans of each. If we’re working on a huge system, Fernox sells the same products in a jug, as opposed to a can. These products have been available in the U.S. for seven years, but your neighbors to the north (or my east) have had it for nearly 20 years.

Based on the fact that I’ve seen numerous systems come back to life from a no-heat situation caused by sludge, we’ve decided that it’s worth using the chemicals on every job. In many cases, it has saved thousands of dollars and number of migraines.

By Jeff Kaufman, Operations Supervisor at Rocky’s Heating Service, Fairbanks, AK

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