B
buckley plumb
been to look at the above heat only boiler today 1 year old on a new build home . seen them before where they make a noise like a jet plane in low or high rate and adjusting co cures it . this one was different sounded like a tumble dryer when put on high rate - co was spot on in high and low rate and target and actual fan speed matched .called glowworm and they said treew co down which made no difference. they then told me it could be fan bearing or partialy blocked heat exchanger . I am not convinced sure I have heard of humming heat exchangers before anyone come across this - all pipes are poly plumb and 1 year as this is an new build . calling them out under warranty but I know they will just blame blocked heat exchanger.