Worcester 240i combi keeps going on/off

[davphi338]

Hi,

My worcester 240i combi boiler turns itself on and off alternatley within a minute or so when the CH is on. i.e the boiler fires up for 30 secs and then the boiler shuts down it then fires up again and there is the sound of relay clicking a few times. The radiators do get hot but I'm sure it not normal for the boiler to operate in this way.

Anyone have any suggestions as to a possible cause

thanks

 

[meldrew's_mate]

I believe the 240 has a manual bypass valve built in, this may be open too much.

Check the diverter valve returns smartly to its resting position, pin fully back, following DHW draw-off.

Otherwise the symptoms are of low flow through the boiler, check the pump.