boiler for radiant heat solenoid banging noise in the boiler cabinet

handysteve

Hi...



I have a radiant heat flooring system, and notice every once in a while while the thermostat calls for heat, I can hear the boiler exhaust vent begin and within the plastic insulated boiler cabinet i hear this loud bang every so often when call for heat.

i took the green plastic cover off the boiler and there appears to be this solenoid control valve that pops and makes a loud bang...loud like a gunshot bang.

I saw a blast of air come out of it once when i timed it right for inspection and the air blast seems to come from a solnoid or valve control.



my question is what causes the bang noise? and how can i eliminate it or reduce the noise?  It can wake you up in the middle of the nite while sleeping.

thanks



Steve