Loud knocking noise from inside wall

[Burpie]

Hello,

We’ve had a new boiler, hot water tank, pump, T-valve and thermostats fitted and are using the original radiators without zone valves (small house). The guy that fitted it says he’s too busy to come back and take a look at the problems.

If we run just the heating, after it reaches the set temperature and the boiler turns off, we hear a loud tapping noise coming from inside the wall from what I think is the return pipe to the boiler. This happens every time the boiler turns off and the pump overruns and it’s driving us crazy.

If we run just the hot water or heating and hot water together it doesn’t happen.

This new install has a bypass fitted and the old system didn’t have a bypass and just a basic pump.

The new hot water cylinder is a lot bigger than the old one but doesn’t seem to hold as much hot water. Unless we leave it on constantly, we run out of hot water much quicker than we did with the old system.

The new system:

Vaillant Ecotec plus 415

Grundfoss Alpha 2L

 

[townfanjon]

Can you post some pics of the install, I smell a rat when the guy wont come back .

 

[Murdoch]

Just give him some negative feedback online ...

tradespeople who wont return to unhappy customers deserve to be names

 

[Jerry]

How can old existing pipework be the installers fault?

 

[Ben-gee]

The noise could be pipework expanding/contracting rubbing against ceiling/joists etc. The pipes probably got moved slightly when connecting new boiler . If you can track down noise, just ease the hole slightly and put something between pipe /wood (cardboard shim will do it)

 

[EastMidsTiler]

The noise could be pipework expanding/contracting rubbing against ceiling/joists etc. The pipes probably got moved slightly when connecting new boiler . If you can track down noise, just ease the hole slightly and put something between pipe /wood (cardboard shim will do it)

Any tips on how to track down the noise? I have a similar problem, driving me mad at night! Can't locate it, I feel like I will end up with holes all over the place before I find it. Got a stethoscope being delivered from Amazon but I don't know if that will help?

 

[plumbingdoctor]

Hello

I think its a bubble that make a noise that stream bubble when its trap and rise to your heater tank

 

[knock knock]

Any tips on how to track down the noise? I have a similar problem, driving me mad at night! Can't locate it, I feel like I will end up with holes all over the place before I find it. Got a stethoscope being delivered from Amazon but I don't know if that will help?

hello, did you have any luck? I am in the same situation, random knocking / banging noises sounding like pipes in the walls!