How much electricity does a gas boiler use?

January 13, 2013 12:29 PM

I know this question is a little bit arbitrary, but any response will be helpful. I live in a 2 family spilt house/condo. I noticed that my electrical box is powering the OTHER unit's gas boiler. I assume that the electrical just feeds the thermostat and maybe triggering the pilot to boil the water?? (My knowledge here is limited.) Without knowing too much about their heating use, I am trying to determine the urgency of getting an electrician to switch it from my electricity to the other unit's electrical box.
posted by lccslug to home & garden (8 answers total)

You're probably also paying to run the pumps that move the water through the system (you might want to clarify if you're talking about a heating system as opposed to just a hot water system).
posted by HuronBob at 12:39 PM on January 13

Sorry, it is the heating system, not the hot water.
posted by lccslug at 12:48 PM on January 13

If it's a water-circulating radiator system, you're probably running the other system's water circulating pump.

If it's an air-blower duct system, you're probably running the other system's blower.


Both of these loads are an order of magnitude smaller than the energy going into the system to actually create heat (the natural gas burner).

If you're getting an electrician to do other work, it's probably worth it to switch it over. I wouldn't do it on an urgent basis.
posted by Kakkerlak at 12:54 PM on January 13

Scroll to table 7.8.5 in this paper (PDF). This suggests electical usage between 100 and 200 KWH per year. The actual depends of course on climate, size of the premises etc. Check your electrical bill for per/KWH cost, but you're probably looking at a ballpark of $30 per year. So I second Kakkerlak's suggestion.
posted by beagle at 12:59 PM on January 13

It is a water circulating radiator system. And thanks. I thought the cost would be small, but I wanted to make sure.
posted by lccslug at 1:00 PM on January 13

One way to check the cost is to switch off every electrical appliance in your home. Make a note of how many units are used for say 10 minutes. Then use your electricity bill to work out the cost per year.
posted by Ranting Prophet of DOOM! at 1:43 PM on January 13

I have a circulating radiator type gas heating system. I use it a lot for about five months of the year and switch it off at the wall the rest of the year. The difference in my electricity bill is very small, maybe five-ten euros every two months (which also includes more lighting, more electric blanket, etc). Yours may use more and it's still worth getting it fixed regardless, but it's probably not urgent.
posted by shelleycat at 2:57 PM on January 13

If you are on the top floor, the cost of running the pump for the other unit is probably offset by the fact that your unit is being heated partially by heat rising from downstairs, and the wiring may in fact be designed to equalize the prices.
posted by kindall at 8:42 PM on January 13