Kettling in a Centra Heating Boiler

[Hero2]

My boiler makes a kettling/whistling noise when the heating is on (although not continually). Heating seems to be working normally just have the annoying noise- what causes this and do I need to get someone to look at it?

 

[Agile]

That can be caused by several things.

Until you tell us the make and model I cannot suggest which one might be the cause in your case.

Tony

 

[Hero2]

Thanks for your response. It is an 'Ideal Classic' wall mounted convectional boiler

 

[xr4x4]

when the boiler heats the rads or the water to temp and cycles off, does it do it then? then goes away when it comes back on?

are all the rads getting hot?

 

[Hero2]

This happens when the boiler is either heating the water or on for heating the rad's - seems to happen for so long then quietens off then starts again.

Its noisey but I suppose being realistic its not really loud. The boiler is situated in the integral garage.

When it shuts off, all is quiet. All rad's getting hot

 

[xr4x4]

have you checked the pumps running?

what speed it on?

system been working before with no problems?

 

[Hero2]

pump is switched on but being honest Im not sure where to locate any switch to adjust the speed?? where might this be??

If I remember rightly, this has happened before but only for so long then it stopped. Heating has always worked ok and never had any issues , only had to bleed the odd radiator occasionally

 

[xr4x4]

the switch for the pump speed is on the pump itself. small white switch in the black plastic bit. 1, 2 or 3. normal is 2. depending on system size i think.

im not saying it is that, but boiling/kettling is normally the sound of the water boiling inside the boiler, due to it sitting inside the heat exchanger for to long.

this normally happens when the pump stops when the boiler is hot.

where is the pump, is it possible to stop and listen to it for a while, or feel it running. ideally when boiler starts kettling.

just thinking, it could also be something else stopping the water, maybe a faulty zone valve or a failed or missing bypass valve.

 

[Agile]

Can you measure or estimate the temperature difference across the flow and return pipes at the boiler? Should be about 11 degrees.

Has anyone serviced the boiler lately? Can you gas rate the boiler from the info in the FAQ on this site?

Tony

 

[Hero2]

Located the pump switch - it is currently set at 2.

Might try altering the setting - see if that may make a difference?????

Boiler is due for servicing as it hasnt been done for around 18mths. Going to get this done early Jan/Feb so I'll get the engineer to check this if its still happening - including the valve issues which have been mentioned.

My thanks to you both for providing your thoughts. Best regards, Matt