Thx for your response.
Would a lack of water flow also cause boiler not to falme up properly as I have noticed that water pump does not kick in either.
Dont know if that's because of boiler flame been low or the cause.
Its a WILO GOLD 05 pump, is there any easy way to check it?
I have a fanned balanced flue Ideal gas boiler and Siemens MAV322C 3port motorised valve arrangement.
When HW, CH or both selected boiler fires up but only with a small flame
(it use to roar into life) water not getting hot.
Motorised valve actuator head (motor) had been making a whining...