What the heck is going on?

chris_95

Well at least the relief valve is brand new :)

chris_95

So for the past 3 days, I come home from work, and find that my pressure has dropped to nothing... I open the fill valve ever so slightly, and it jumps back up to 20 psi. I'm also hearing a very odd noise, its a loud thumping/pounding that gets louder, lasts about 20 seconds then goes away completely... its when the burner/circulator is running, but it can be fine for all day, and then it just randomly makes this noise. I notice a pressure drop sometimes when it makes this noise... I don't see water anywhere, where the heck is it going?? I tried running it up to 180 and kicking circ on full time and purging air from all the radiators, but all I get is water.... Any ideas??

Pictures and more info about my system are at:
http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=51787&mc=20

look at bottom of thread for complete pics

Thanks in advance!!

ScottMP

Chris

go outside and check the chimney when its running. Look for white smoke/steam. You could have a cracked section and the banging is the boiler flashing to steam with no/low water in it.

Scott

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

chris_95

correct me if I am wrong, but wouldn't I see water near my boiler? Also the radiators on the top floor are still full of water, so it has to have water in it, right?

Paul Fredricks_3

Not necessarily. A small leak into the combustion area will evaporate before it gets to the floor. Yes, there's still water in the system, but the pressure could be bleeding off into the chamber.

Turn the unit off for 10 or 15 minutes and have someone else turn it on while you watch the chimney. You should not see white smoke (steam).

bob_46

Chris

it sounds to me like your expansion tank is water logged. bob

chris_95

Thanks Paul and Bob. Paul I removed the cover to check for any evidence of water damage, and also did the chimney thing, no problems there... Bob, what do I do for a water logged expasnion tank? Can I just shut the valve off that goes to it, and unscrew it and empty it, or I guess its under pressure?

I just called my gas company today to get the line into my house to prepare to replace my boiler soon

hvacfreak

my first thought too

but the disussion made it to a " breech " so soon I was afraid to say that , lol. Start with the most severe possibility and work backwards...hmmm...ok. How about this one...if the structure is still standing in the morning check the fluid level in the expansion tank...that just sounds bad. Anything is possible for sure. -M

hvacfreak

posting times

we were 1 minute apart , lol. Isolate the tank ( or piping section that it's in ) and drain down. If you can't isolate it than you'll have to drain the system...just remember that air replaces fluid when you do this ( or a vacuum is formed ) and needs to be dealt with when you fill the system again. The tank will need a precharge of air before putting it back into service as well ( might be a good time to at least speculate why it lost this ). You'd do well to call a pro on this issue for sure...there are too many varriables to call this a " simple " fix. - M

chris_95

ok thanks, its a brand new amtrol bladder expansion tank. theres no drain just a air chuck at the bottom. do I just unscrew and empty?? I'm guessing this might make a mess and spray all over me...or isn't the pressure an issue?

hvacfreak

yeah

you'd do yourself a favor by closing the fill valve and opening the boiler drain ( after isolating any system piping that you can ). Manually open the relief valve or something to introduce air I guess.

Just remember that the tank filled with fluid for a reason , of which can be many. -M

Chris Bunting

Ok, so I took the tank off, no water in it, was pressurized to 12 psi. so I pressurized it to 15 (my sys pressure) like it should have been from day 1 as I understand in the instructions... put everything back together, added a little water and purged air...everything is running OK so far... we'll see how it goes I guess... still gonna replace the unit once I'm out of oil, which wont be long with this oil eating beast I have OF COURSE I will be keeping the BLUE in the house...getting another Burnham

[Deleted User]

If you're the same guy that had another thread going with photos of your boiler, one of the pictures looked like your expansion tank was connected to your domestic water. Maybe it's time to get a professional out there to check it out.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"