Soapm
Member
I had to change the fresh water pressure reducing valve on our boiler at the church. Thanks to reading this forum, the boiler was staying at 30lbs with constant seepage from the PRV. I found I could shut off the fresh water supply and the system would stay where ever it was set for days. Open the fresh water supply and the system would slowly rise over the course of a few days until it hits 30lbs and the seeping starts.
While I had the system down I changed the reducing valve, expansion tank and PRV. However, not knowing what I was doing I let the air out of the expansion tank trying to check the level. I did it with the system pressurized so it was reading high and I kept trying to reduce it to 12lbs and now it's out of air (my bad).
I would hate to have to open the system and purge it again since that took about 4 hours to get all the air out of all 5 zones.
If I turn off the fresh water supply then open the PRV and let the system go down to zero, is that sufficient to adjust the expansion tank? Does opening the PRV introduce air to the system? I don't know the normal process to adjusting the expansion tank but taking it off the system means completely draining the entire system since there is no shutoff valve going to the expansion tank.
Also, the new reducing valve holds the boiler right at 20lbs. It used to sit about 15lbs. We have two floors, basement and upstairs with 5 zones. Is there any reason to adjust the reducing valve down to 15lbs or can I get by leaving it at 20lbs. I prefer to leave it at the factory setting if there is no potential harm.
Lastly, if the new pressure reducing valve holds the system is at 20lbs, where do I set the expansion tank? That's why I was looking at it, my logic was if it's set at 12lbs then it will stay full since the system will always be at a higher pressure. My logic is it needs to be set the same (20lbs) or slightly above the system pressure (22lbs). Am I on the right track?
While I had the system down I changed the reducing valve, expansion tank and PRV. However, not knowing what I was doing I let the air out of the expansion tank trying to check the level. I did it with the system pressurized so it was reading high and I kept trying to reduce it to 12lbs and now it's out of air (my bad).
I would hate to have to open the system and purge it again since that took about 4 hours to get all the air out of all 5 zones.
If I turn off the fresh water supply then open the PRV and let the system go down to zero, is that sufficient to adjust the expansion tank? Does opening the PRV introduce air to the system? I don't know the normal process to adjusting the expansion tank but taking it off the system means completely draining the entire system since there is no shutoff valve going to the expansion tank.
Also, the new reducing valve holds the boiler right at 20lbs. It used to sit about 15lbs. We have two floors, basement and upstairs with 5 zones. Is there any reason to adjust the reducing valve down to 15lbs or can I get by leaving it at 20lbs. I prefer to leave it at the factory setting if there is no potential harm.
Lastly, if the new pressure reducing valve holds the system is at 20lbs, where do I set the expansion tank? That's why I was looking at it, my logic was if it's set at 12lbs then it will stay full since the system will always be at a higher pressure. My logic is it needs to be set the same (20lbs) or slightly above the system pressure (22lbs). Am I on the right track?