Expansion Tank - Boiler

Lee Wallin_2

I have a gas fired hot water heating system. The expansion tank was damaged due to being bumped into. I drained the system, screwed of the old, and screwed on a new.

My pressure release valve was going off when it was within the normal temperature range. From a previous posting I was told the expansion tank might be filled with water. I drained the system, took it off, and it is.

What did I do wrong? How do I fix this?

Thank you.

Unknown

Ex tank

Lee, ya lost me a bit here. You had a tank, then somebody "bumped" into it,and you replaced-it, now there`s a problem?

Unknown

Tank

Lee, the expansion tank is there because when you heat water it "wants" to expand, so you need a place for it to go. If the "relief-valve" goes off, you had better find-out why. It may be the "tank" was too small to begin-with, or a feeder problem.

Lee Wallin_2

Thanks for the reply. Other than draining the system, is it simply a matter of screwing off one tank and screwing on the other? Any other steps?

rox

question

you put the new expansion tank on then you had to re-fill your system with water, what did you do to blead the air out?

Ron Schroeder

Lee

if it is a bladder tank make sure there is a twelve pound charge of air in the bladder. Check it with no pressure on the water side of the tank. If your normal pressure is higher than twelve match that pressure.

If is the old style without the bladder then drain it close the drain and air inlet port and recharge with water.

Weezbo

Go see relentless by Jet Li ....

and call a professional to stop by while you are enjoying the movie....

Unknown

Ex Tank

Bruce and Bill`s right, I forgot to tell you that. If, "and I`m assuming it is" a diaphram type tank, the air charge should be the same as the system pressure, but you gotta check-it with 0 system pressure. The "bladder" and system are 2 different things.

Lee Wallin_2

Expansion Tank - Boiler -Almost there

Your advice has been great. My Expansion Tank does have a bladder. I have the pressure set to 12. When flushing the system of air, I did use the override to let city pressure in to speed up the job, and must have let too much pressure in. Boiler heats up properly, the pressure stays between 12 and 20 while working, and the release valve does not go off. THANKS.

What is the best way to flush air? I know I may not have the terms right. Is it to shut off all valves, and for one zone at a time: 1. Connect hose to drain valve and put other end
in sink, 2. open zone valve, 3 - open shut off valves, 4. Allow auto-fill presure to flush system OR should I open auto fill override and watch the pressure. Is there a better way?

Although suggested in a previous posting, I did not go see Relentless by Jet Li. Is this a critical part of the process?

Ron Schroeder

Lee

shut off ball valve after the purge valve at each zone and one by one one open the zone valves and purge them out. I usually over ride the feed valve as it makes it easier to get the air out, just keep an eye on the pressure keep it under 25PSI to prevent opening of the relief valve.

Dave_105

Lee................

As I don`t know what kind of rads you have, or how the system is set-up, I can only tell you what I do. Think like water, bleeding gets rid-of trapped air which will rise, so I start at the lowest rad in the home and work my way up. PS- Glad you got the tank situation solved!!!