Pipe Hammer

[stevenrafferty]

Can anyone help?

I recently had two radiators on a combi boiler heating system repositioned, using the existing thermostats on the radiators.

However, now that the cold weather is back, we are getting "Pipe Hammer" when the thermostats get the to the set temperature.

Anyone know what is causing this/how to fix it? I will obviously need to get my plumber back but would prefer to know what needs to be done first.

Thanks

 

[Bas]

sounds like the valves were installed the wrong way round. newer ones can be installed either way but older ones not so. there may be an arrow on them to indicate correct flow direction

 

[stevenrafferty]

We did install new reads, but reused the existing thermostatic values, which are modern ish. These were simply taken off the old rads and installed ion the new.

Might they be on the wrong way round?

Can I fix the existing valves or is it eaiser just to get ne valves fitted?

Cheers

 

[Bas]

if the noise is coming from them then they are the wrong way round. Its easy to do. as i said check the flow arrow on ther valve body

 

[stevenrafferty]

I will check the arrows.

Just thinking, could it be caused by the thermostat being installed on the output side of the rad?

I would hope that my plumber got it the right way!

 

[Malc]

Do you have a automatic bypass?

If you don't and all the TRVs are closing the pump head will rise and that will cause hammer, especially if the valves are on the wrong side and so more prone to it. In this is the cause the hammer will stop if you open a valve.

 

[stevenrafferty]

No idea if we have an automatic bypass?

The hammer stops when I turn the valve, either up or down and then can sometimes start again, I presume when it gets to the new temperature and is trying to close?

I will check the direction of the arrow, see if they are on back to front

cheers