Banging noise in central heating system

[RK_London]

I will try again

 

[RK_London]

Cylinder connections

https://www.dropbox.com/s/4xkennnxju5n5j8/2020-12-23 23.23.36.jpg?raw=1
https://www.dropbox.com/s/ctvk0b4veujmp7d/2020-12-23 23.23.57.jpg?raw=1

 

[ianmcd]

in your second pic the top pipe going into the cylinder with the two port zone valve on is the flow , does that get hot first before the lower one ? To post a pic just click upload a file from the bottom right of the page from on here

 

[RK_London]

Heating is on and right now top on is hot and bottom one cold. What's the best time to check which pipe gets warm first?

 

[Harry Bloomfield]

Heating is on and right now top on is hot and bottom one cold. What's the best time to check which pipe gets warm first?

Just as soon as the boiler fires up, the temperature of the flow pipe will quite suddenly increase, with the return pipe being obviously cooler - so a hand on each.

 

[RK_London]

Flow pipe warming up before the return on the boiler. The flow pipe connecting to HW cylinder (top pipe) is warm but not as warm as the flow pipe going into boiler although they are connected to same pipework.

 

[ianmcd]

sorry just re read your posts and see the cylinder was changed at the same time as the new boiler so the test I asked you to do is not conclusive

 

[RK_London]

Effort appreciated

 

[RK_London]

General question - is it reasonable to ask my installer if he balanced system after powerflush, new boiler, new cylinder and three new radiators? I'm putting together a list of things I want my installer to look at when I ask him to come back

 

[Harry Bloomfield]

General question - is it reasonable to ask my installer if he balanced system after powerflush, new boiler, new cylinder and three new radiators? I'm putting together a list of things I want my installer to look at when I ask him to come back

From my experience - many installers will have heard of balancing a system, but generally try to ignore it. They lack the time or patience to do it properly. In my opinion (others will disagree), it is balancing is not as crucial if their are TRV's on all radiators and they are appropriately adjusted.

 

[RK_London]

thanks - some of my noisy radiators do not have TRVs ( bathrooms and Hallway where the Thermostat was originally fitted)

 

[denso13]

some of my noisy radiators do not have TRVs

I'm not convinced the system is piped up incorrectly and if some of the noisy radiators don't have TRVs then I'm even more convinced.

 

[RK_London]

what do you think the problem might be?

 

[ianmcd]

One faulty Trv will echo through the whole system , the only way to find which TRV is causing it , is when the noise happens put your finger on the TRV dont turn it and you will feel it

 

[Harry Bloomfield]

thanks - some of my noisy radiators do not have TRVs ( bathrooms and Hallway where the Thermostat was originally fitted)

The noise from one TRV will go all through a system, the only way to be sure which is the cause, will be to adjust the setting up or down to see if it stops.