Central heating "kettling"

[TallAndy]

Hi all

A few months ago I flushed the system (I forget which product) then added an inhibitor, but have found that it is still "kettling". The boiler will come on then after a minute the pipework starts making sounds like a kettle coming to the boil. A minute later the boiler shuts off (I guess because it has reached temperature) and the kettling stops. The CH pump carries on going, then after a couple of minutes the boiler comes back on and the process starts again.

I'm wondering if I didn't flush the system properly. I followed the instructions on the bottle but was surprised that it only told me to circulate it for half an hour before draining the system. I've since read other posts recommending that it's left in the system for a week (or 48hrs continuous). What would you folks recommend?

Is it likely that the flushing wasn't thorough enough or could the kettling be caused by something else? Radiators seem hot enough, although it takes them nearly 2 hours (this is with the boiler also heating the hot water). If it makes a difference they all have TRV valves (except the one in the hall where the thermostat is), and most are all turned up full.

It's a Potterton boiler (I forget the model). One of the neighbours told me a plumber said this model was underpowered for the size of house. BTW would changing the pump speed make any difference to anything? It's currently on its middle setting. And what difference does the temperature dial on the boiler make (it's about halfway)?

Thanks in advance

Andy

 

[ChrisR]

would changing the pump speed make any difference to anything? It's currently on its middle setting.

Turn it up

And what difference does the temperature dial on the boiler make (it's about halfway)?

It sets the temperature the boiler gets to. Turn it up.

More info would help.


See FAQ on kettling.

 

[stardanny]

Hi.

I had a Potterton Neatheat 10/16 boiler for 23 years, at the last year, it sound like a kettle boiling, I found out it was limescale inside the heat exchager, creating hot spot inside above the burner and it what sound like a kettling noise meaning it come to end of it life. I had to replace the boiler with Baxi Solo 50pf. If I was you, I replace the boiler.

 

[stardanny]

other thing, I wouldn't use a descaler for boiler, yes it will remove scale but the exchange might have a pin hole leak and scale may be pluging it up.

Hope this help.

Dan