Noisy Forced Hot water system


Old 12-07-12, 12:34 PM
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Noisy Forced Hot water system

My forced hot water is making a LOT of noise - not flow noise through the pipes. Sounds like an old man who has smoked all his life wheezing for breath.

I know systems need to be bled and that may be it but as I read the posts
I am at 12.5psi at c200F which sounds like its 8psi too low.

There are so many pipes and valves for just 2 measly zones I am at a loss.

So I took some pics...and as i did that I saw some crystalline deposits on a joint...I wonder if I have a leak?

Noisy boiler - a set on Flickr

And one last thing ... which may be totally unrelated...there is a green valve/tap with hose threading toward the bottom of the tank which for some reason started dripping a few days ago...quite a puddle. The valve is remarkably easy to turn (very light finger pressure will turn it) we think a few of our foster kittens may have played on it...or is there a system reason? Since we tightened it it hasn't leaked.
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Old 12-07-12, 12:56 PM
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Several things you will need to do IMO to start.

1, Change that air vent on top of the air separator.
2, Check the charge in the exp tank while changing the air vent.
3, Let the boiler cool and when adding water adjust to about 15 psi cold. May need a new fill valve. I see a new back flow but why did they not change the fill valve too?
4, Lower the boiler temp. 180 should be OK. Check and take pics of the aquastat.
5, Read stickys on on how to adjust psi in exp tank and how to verify tour pressure gauge.

At a minimum that above would be needed, then see how she runs....
Old 12-07-12, 02:39 PM
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Here are some thoughts in addition to those that Mike posted.

Yes, your last picture shows a fitting that is leaking. It could be the soldered joint or, less likely, a pinhole in the fitting itself. You can probably wait until spring, at which time you'll have to drain the system below the level of the fitting to replace it.

Is the noise coming from the combustion chamber? Sometime boilers rumble.

But first, depressurize the system, pump up the expansion tank to 15 psi, and refill the boiler to 15 psi (cold). That may solve the noise problem.

I know systems need to be bled and that may be it
No, the system doesn't ever need to be routinely bled - that just adds air. But in your case, it needs to be depressurized, which does require draining until the pressure is zero.
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