water hammer update

thankyou all for your help here is a bit more detail

changed water tank thermostat
actuator changed
have not yet changed boiler thermistor
have not changed room thermostat

I put the boiler on and after half an hour the pump stopped working
the boiler was still going and started to hammer
i then turned off boiler manually
pump did not come on to disperse heat

suggestions please

Why start a new topic? You should have added this to the end of your old one

D_Hailsham said:

Why start a new topic? You should have added this to the end of your old one

Click to expand...

ok