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Re-filling baseboard heaters???

I drained my system to replace some baseboard heating elements (slantfin/30's) and when I tried to refill the system the top floor did not get refilled for some reason. Every search I did on here lead to "Venting" the units but I have a continuous loop so there are no vents? How do I refill the system completly???

Re: Re-filling baseboard heaters???

I replaced my Dads Boiler had the same problem. If there is no bleeder valves on the base boards. then there should be a expansion tank located in the rafters somewhere near your boiler. you have to keep bleeding water off that tank. it took him a few weeks to get water to all the fin tube units. I hope that helps

Re: Re-filling baseboard heaters???

Well now that its getting warm out, a few weeks is ok since I dont really need the heat but Im more interested in finding potential leaks... I dont want to find out in a few weeks if I have one... I might try to play with the expansion tank a little.

Re: Re-filling baseboard heaters???


Hot water systems which have the old-style expansion tank between the floor joists above the boiler don't have bleeder valves on the radiators/baseboards.

Instead, these systems usually have what's known as purge stations on the return piping of the boiler.

If you have just one zone, you probably have just one purge station.

They look like a regular faucet connection connected to a stop/shutoff valve on the same brass housing.

The idea is to turn off the boiler switch, connect a length of garden hose to the purge valve, put the other end of the hose into a plastic bucket, shut off the main vent with the shutoff valve, & hit the "fast fill" on the pressure reducing valve, so that a lot of fresh water can run thru the piping, & drive the air out of the system.

When the bubbles stop coming out of the garden hose, the air has been completely removed---your pressure gague should read ~12 to 15 psi on the pressure gauge when the boiler is cold.

Google "purging air from a hot water system" (without the quotes) to get more info.

The bell-gossett site below has photos of the different valves mentioned: click onto "homeowner" at the site, then scroll down & click onto "valves", then onto pressure reducing valve, fast-fill, "purging valve". etc.

Post back if you need further help.


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