HEATLINE COMBI BOILER

I have just had a Heatline Combi boiler and new piping installed.

From day One i have had problems.
1) Humming noise when hot water is on
2) Faulty Switch, which was turning the boiler off!
3) Thumping noise when the boiler ignites.

Apologies for my lack of terminology.

Heatline have been out once to commission it and sort out the faulty switch but the other two noises they say are "Good" noises?

Number one i can cope with but 3) sounds like the thing will explode every time the burner ignites! A real thud that even makes the casing of the boiler expand. It seems to take a long time between the gas being released and the thing igniting.

The engineer I had said you either have it this way or turn down the amount of gas released and then risk the boiler keep going out?

It doesn't always thud, maybe 80% of the time.

I would like to know if anyone can help or has had the same problems with heatline?

i've also started to have the pipes start to knock even though i have bled all the rads?

Thanks

humming noise could be caused by loose pipework or tap washer

thumping noise is caused by gas igniting too late (small pilot) or as you noticed too great a gap between - shouldnt happen

Cheers,

Does this mean that (like the Heatline bloke said) the amount of gas released needs turning down but then risk the boiler going out? It has already been turned down a bit.

better that the pilot light is aimed towards burner to catch gas as i t is released from jets