water hammer with central heating

[greg555]

Hi,

When my room thermostat reaches temp (the LED turns off) Is it common to hear water hammer? The noise seems to come from above my celling in the living room. (where the motorized valve must be) and can be clearly heard shutting 3-4 times a night.

Could this cause damage?
Is it common to hear water hammer from your heating system?
Should this be silenced or buffered in any way?


additional info- I think I have a combi boiler (its set at 1-1.5)

any replies would be appretiated !!

cheers!,
greg.

 

[Softus]

Sounds like you have a two-port valve and no bypass on a boiler with pump overrun.

 

[LUNAT]

HI

sounds like pump stops immediately when the boiler/burner stops thus causing heat to remain inside the boiler.
1.no by-pass fitted
2.by-pass fitted but closed

 

[Softus]

sounds like pump stops immediately when the boiler/burner stops thus causing heat to remain inside the boiler.

What on Earth are you talking about?

 

[namsag]

Danfoss motorised valves have a habit of making a hell of a clunk as they close when they start to wear so if you have one of those that maybe your problem