Hot water tank sounds like running bath..

[Jimothy]

Hi all,

had a radiator replaced yesterday, and since then, whenever the pump that circulates the HW/CH is running, there's a very noticeable "running bath" type sound eminating from the hot water tank. This didn't happen previously.

Now, looking in the airing cupboard, it seems that our system has a short loop of pipe that connects the outlet (lower, "cold" end) from the tank's heat exchanger back to the pipe that lies between the pump and the inlet to the heat exchanger (This strikes me as odd, as it bypasses the boiler, and effective creates a "short circuit" between the hot and cold ends). There is a stop valve on this loop, and my gut tells me that is should be closed in normal operation, and it was left open by mistake - if I close it, then the running water noise stops, but I don't want to leave it that way just in case I've misinterpreted what purpose it serves.

Any ideas?[/i]

 

[Armo74]

Check all vents are bled.
Check water level in feed and expansion tank and ball valve operation.
The pipe you are talking about does sound like a by-pass which has a gate valve on it to regulate flow through the boiler.
If everything was ok before leave it alone otherwise it is likely to leak.
I would hazard a guess that the sound is due to the system not being filled properly.

 

[Jimothy]

If everything was ok before leave it alone otherwise it is likely to leak.

The thing is, the plumber who fitted the radiator may well have fiddled with it, so I have no way of knowing if it's still set as it was before the work was carried out.

I would hazard a guess that the sound is due to the system not being filled properly.

Actually, my initial thought was that maybe there was air in the heat exchanger somewhere, but then I noticed this odd little loop and discovered by chance that it had an effect on the noise, so that's what made me think that a change here was a likely cause.