when gas burner lights it makes a noise . as if the burner is not burning all the way round . it then goes quite and burner is lit correctly after about 1 min. is this due to lack of gas pressure, and is the gas pressure ajustment on the throttle screw on the gas valve.

mark,, November 2009

This boiler has a premix burner. Do not adjust the throttle unless you have a gas analyiser. The gas pressure to the boiler may be the problem but you must get a qualified person who is registered with gas safe to check this.

peter, November 2009