Boiler Noises!!

[MarkGrainger]

Hiya

When our central heating switches on at the programmed time each day, it sounds like it is filling up with water for about 5 seconds from the main feed pipes then it kicks in, is this correct.
Secondly, we periodically have to vent one of the radiators to release the accumulated air (approx once a week/fortnight), i'm not sure where the air is coming from. It is only one radiator that needs to be vented, all the others are ok but this radiator always seems to be very hot!!
Thirdly, the boiler pilot light goes out occasionally, sometimes once a week then doesn't go out for weeks after, the boiler does tend to get hot and the temp regulator on the front is at its lowest setting. Occasionally i hear a wooshing noise from it and a loudish bang.

Lastly, we hear a vibrating noise from the under the floorboards once/twice a day for a split second in one particular room, pump related??

Any reasons/remedies for the noises etc.

thanks

mark

 

[corgiman]

what boiler do you have?

 

[MarkGrainger]

Its a Potterton prima B

 

[MarkGrainger]

sorry, should have said When our central heating switches on at the programmed time each day, the boiler sounds like it is filling up with water for about 5 seconds.....

 

[pannierstan]

You did already say that?!

Possibly not actually air that you are bleeding, but Hydrogen (dont worry you wont blow up!)
Its possibly you have a reaction going on in the system or the system is justed piped wrong and is either entraining air or pumping over again causing ingress of aerated water.

Stan

 

[gas4you]

When you bleed radiators do you evenyually get water out? If not check water level in header tank. If no water out of radiators and header tank full it suggests blockage. 99 times out of 100 it will be where the cold fill joins the system.

 

[Agile]

It certainly sounds to me as if the header tank is empty or the feed pipe blocked!

Tony

 

[MarkGrainger]

I've just looked at the header tank and thats got water in it ok, the ball cocks working also.......and to the earlier question, yes, water does eventually come out of the radiator (i do switch off the pump first so no air is being sucked in).

 

[stevesey]

It is only one radiator that needs to be vented, all the others are ok but this radiator always seems to be very hot!!

I'd guess that this rad is the closest to the pump, hence it gets the hotest water and is trapping the air before if can get anywhere else.

 

[MarkGrainger]

it is an upstairs rad in question, i guess it could be pretty close to the pump without lifting the floorboards up, i don't know.

 

[gas4you]

Go into your loft and watch the header tank vent pipe whilst someone else switches heating on. Does it pump over (water coming out of the vent pipe) for this 5 secs?