I don't know if anyone remembers me, I had a really long thread on here last year.

Now that we're into heating season, I"ve noticed again that I don't have heat on the second floor of my house. I checked the pressure and it was near zero. I do have heat on the first floor and the boiler is in the basement.

I drained the expansion tank and it still didn't raise the pressure, so I added fresh water to the system until the pressure came up to about 17 (this was the normal pressure from before). Then I bled the air out of the lines, but when the boiler runs, it still isn't circulating hot air to the second floor. Everything seems to be working properly. Any ideas?

 

I meant to say that it isn't circulating hot WATER to the second floor.

I've also noticed today that the pressure is going over 30 psi, and the overflow valve thingy is leaking. I'm thinking that the PRV or the fresh water intake valve are/is leaking?

 

Your pressure relief valve seems to be lifting - it's probably set at 30 psi.

It seems that your expansion tank isn't doing its job? What type do you have: the diaphragm type (with a rubber bladder separating the air from the water) or the standard tank (where the air bubble is in direct contact with the water)?

Draining the expansion tank shouldn't increase the system pressure.

If pressure drops too low, air can be sucked into the system.

You first need to figure out why the pressure is going haywire.
Doug

 

Thanks for your response! It's an older type expansion tank, not one with a bladder. I let fresh water in via the PRV and the valve to raise the pressure and that worked, but now the pressure is getting too high. I think I have a leak/faulty valve or PRV. I'm going to try to replace the old valve with a ball valve first. Does that sound like a good plan?

 

No, I think you need to figure out why the pressure is going haywire first. I think your expansion tank is waterlogged. You'll need to open or drain the system to the point where air is admitted to the expansion tank. The procedure for this depends on how your tank is valved.

Do you have an "airtrol" fitting that diverts air into the tank? Without one of these, your expansion tank will likely become waterlogged again.

Draining by manually lifting the pressure relief valve isn't a good idea, and may have contributed to your expansion tank becoming waterlogged? And if the relief valve is simmering with the system pressure at the PRV's set point, say 30 psi, there isn't necessarily anything wrong with the PRV - it's doing what it is supposed to do.

You say the you intend to replace the "old valve" with a ball valve. What "old valve"? Not the PRV, I hope!

You said that you drained the expansion tank. Did you get it vented to atmosphere to fill it with air or did you just open the drain valve on the tank and let some water out of the system?
Doug

 

Ditto what has been said above. Fix these issues first then realize you have air in the upper lines that needs to be bled or forced out. If air is entering the system it will always find the high point. Do you have bleeders on the upper floor part of the system? When we had a zoned hot water system with no upstairs bleeders I had to force water thru the upper zone with the fill valve to get the air down to the bleedoff valve or out of the system. I did this by attaching a garden hose to the system drain and draining it outside, then while opening the upper zone and closing the others I opened the valve that adds fresh water to the system, forcing water thru the upper reaches of the system and let it run till the air came out.

 

I already drained the expansion tank. It isn't waterlogged. I meant to say that I wanted to replace the valve that lets in fresh water, rather than the PRV. It's very old and I suspect that it's leaking water into the system and raising the pressure every time the boiler runs. It's set at 30. It keeps raising above that when it runs and is about 25 cold. I was draining off water after each time it runs in order to reduce the pressure.

When I say that I drained the expansion tank, I shut off the valve before the tank, then drained it completely. Then after turning the boiler back on, I SLOWLY allowed water to flow back into the tank. It fills to about 1/2 to 2/3.

I bled all of the lines on the second floor, furthest away from the system. There was some air, but I bled all of it out.

 

Deanna, did you do all the things that I suggested last year be done this this summer? If not then you have no one but yourself to blame. Heating system repairs are to be done during the non-heating season.

 

I just replaced the old valve with a ball valve today and everything is now running smoothly, for now anyway. I know it's my fault. I was so tired of messing with it, it got to be really frustrating. It's not really very cold yet, so I was trying to get it done a little ahead of time. I guess the next thing is to redo all of those pipes?