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bucky
Water run back

I just moved into an older home with baseboard hot water heat. When we moved in a month ago the relief valve was dripping slightly. One night it blew off and we could hear water running back in the tubes after the pump shut off. A day later that stopped and went back to its quiet running again. The water softener was not working, old model, and I replaced it with a new one, now the running water sound is back again and not going away. The relief valve is dripping more after the pump stops. What is going on and how do I fix it. The house is not cold, but the boiler cycles alot. Any suggestions?

johnjh2o
Re: Water run back

The water you hear running is the auto feed refilling the boiler to it's proper pressure after the relief valve blew off. The reason the relief blew was because of excess pressure. There should be a expansion tank to prevent this from happening. There are two types, one is a bladder tank the other is just a small tank hanging between the floor joists. If it's a bladder tank it may have to be replaced. The other type may just need draining.

John

bucky
Re: Water run back

Thanks John,
I have the steel tank between the floor joists. Do I need to completely turn the boiler off, thermostat, gas and water, or just the water and open the faucet on the tank? Would I be able to change the blowoff valve at that time also, or does that take draining all the water out of the baseboards?

johnjh2o
Re: Water run back

There should be a valve between the boiler and tank. If you turn that off before draining the tank you will not drain the boiler. Be sure to turn off the boiler so it wont come on when your draining the tank. After draining the tank turn the valve back on, after the tank has refilled then turn the system back on. The relief valve may not have to be replaced after the tank has been serviced. Keep in mind that it may take some time to drain all the water from the tank, and it must be totally empty. If you are not sure how to do this I would call a heating contractor.

John

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