Posted by Chadwick T. Morgan on October 05, 2001 at 12:02:00:
In Reply to: hotwater/expansion tank questions posted by Roger on October 05, 2001 at 07:38:00:
I have the same sort of problem. The PRV appears to be fine, keeping static room T pressure at about 12 psi. There is a cutoff between the expansion tank and boiler - the expansion tank is above head in the basement and is fitted with an B&G airtrol valve. I have followed B&G's online manula to the "T" and implemented my own procedures and I still connot keep the expansion tank from refilling.
My boiler supply is directly from my hotwater heater, using well water at about 40-50 psi. The PRV is not blocked - prior to my purchasing the house, I ran the circulator pump and boiler - while cool, the boiler maintained the set 12 psi. I have since drained quite a bit of water and it refills appropraitely. But when I do the expansion tank draining (using several methods because none have worked so far) I will open the supply line - and hear the tank refill as if there is a hole on top - but absolutely no leaks I can determine - if it is an air leak, I think it would have to be small, but then would take several hours/days to allow water to fill the tank.
So, when I fire up everything, I eventually hit 30+ psi and the relief starts to go. I have purged radiators per known procedures, as well.
What gives? I am near Chicago and we are in for colder weather shortly. I am an ex-navy machinist mate and now an engineer, so please, anyone, speak in whatever terms you wish but I need some quick advice. Thanks, C
: I've notice this heating season that my boiler psi is running around 30-35 and bleeding off excess pressure constanlty. I've drained the expansion tank and re-filled. This brings it back down to around 18-22 psi which is wher eit used to run at. Problem is that it gos back up after a day or so. Do I need a new expanion tank? Why is the pressure running so high?