noise in central heating system

have just had gas central system upgraded [ new condenser boiler, thermostats on rads etc] but now I have a constant noise like a duh, duh, duh, which seems to be coming from thr radiator/pipes. Called out the plumber but he said it was just the pipes contracting as they heated up or cooled down but I've never had the problem with my old system and the pipes have not been changed. Help please the noise is driving me mad!



thank you Lemrac

I've got a whistling boiler. It's doing it right now...

Or is it a secret admirer?

BM

I had this in a new property,it was so bad it used to wake me up in the morning.Every tool on the site looked at it scratched their heads a gave a different excuse,i traced it to the thermostat in the hot press being turned too high or low (can't remember),a little turn left or right and hey presto never heard the noise again !.so much for the professionals..........

thanks will try the thermostat but isn't there soemthing about not having it too low because of Legionaire's disease and warm water? If so how low can i safely go on the thermostat on the cylinder?

lemrac said:

thanks will try the thermostat but isn't there soemthing about not having it too low because of Legionaire's disease and warm water? If so how low can i safely go on the thermostat on the cylinder?

Click to expand...

My cylinder was heated by electric for showers baths etc.,it was when the heating (gas) was on that the banging started although the heating would half heat the water in the cylinder.Still traced it to the thermo in the hotpress !.I'm no plumber though.