“Tinkling” sound in system

northernsoul

Hi there

Gas boiler system with original 1930s rads and metal expansion tank.

This last day or so it sounds like a tinkling sound coming from pipes/expansion tank in the boiler room. It happened around this time last year as well and lasted for a few weeks. Hasn’t happened until now this heating season

Not sure if a pipe is loose or there is something in the tank- it’s like the sound of a small piece of metal moving or the sound when a pot lid rattles when boiling .

Expansion tank was emptied and recharged weeks ago.

Any ideas ?

northernsoul

I should add that it seems to mainly happened when system starts and then for about 30 min after it shuts off.

JUGHNE

How about a rattling flow check valve; would only chatter when the pump is running.

northernsoul

Is that the pressure setting valve on the water pipe ?

JUGHNE

Back up and take pictures around the boiler.

northernsoul

I can do that - we did just replace the auto feed valve this year

northernsoul

> @JUGHNE said:
> Back up and take pictures around the boiler.

JUGHNE

Need to look at the pipes above the boiler.

northernsoul

> @JUGHNE said:
> Need to look at the pipes above the boiler.

JUGHNE

Does the sound correlate with the pump operation.
Can you back up more for pictures....too close.

northernsoul

> @JUGHNE said:
> Does the sound correlate with the pump operation.
> Can you back up more for pictures....too close.

Good question - how long would a pump normally run after it stops heating ? The pump is very quiet so I’ll need to go inspect next time it runs.

I had thought it was maybe something loose in expansion tank . Hard to isolate sound so far

northernsoul

Pic

JUGHNE

I don't see any flow checks in the pictures.
They could be hiding somewhere in there though.

They were to prevent unwanted gravity flow of hot water in parts of the system. The pump pressure would lift a weighed disc in the valve. Sometime not enough pressure to completely lift and produce chatter.
You may have only one zone however.

Google "Flow check valves" for pictures.

northernsoul

Thanks I’ll have a look. I had thought maybe it was a loose piece of solder in a pipe or tank rattling

Jamie Hall

It it's really tinkling, and not a lower frequency sound, it might be a little air in there somewhere. Or even expansion -- which might have an almost musical "plink" kind of sound.

northernsoul

> @Jamie Hall said:
> It it's really tinkling, and not a lower frequency sound, it might be a little air in there somewhere. Or even expansion -- which might have an almost musical "plink" kind of sound.

Yes it’s a high frequency tinkling sound - hard to describe but like a small piece of aluminium rattling in a jar etc.

northernsoul

Well turns out it was a nail from subfloor above that was resting against top of tank so when system was running and vibrating a little it was rattling against nail.

Whoever did the new floor a few years ago didn’ pay attention to the basement fittings

Fred

northernsoul said:

Well turns out it was a nail from subfloor above that was resting against top of tank so when system was running and vibrating a little it was rattling against nail.



Whoever did the new floor a few years ago didn’ pay attention to the basement fittings

You're fortunate they didn't drive a nail into the tank. Glad you got this resolved.

northernsoul

> @Fred said:
> Well turns out it was a nail from subfloor above that was resting against top of tank so when system was running and vibrating a little it was rattling against nail.
>
>
>
> Whoever did the new floor a few years ago didn’ pay attention to the basement fittings
>
> You're fortunate they didn't drive a nail into the tank. Glad you got this resolved.

Tell me about it!