boiler switching on and off once hot.

[The3]

Hi everyone.

This is such a useful forum.
I would appreciate anyone who could help me out with my problem.

I'm currently using a potterton suprima gas boiler which is about 10 years old. It heats both central heating and hot water.

The boiler works well most of the time but i noticed that once its up to heat , i.e hot water tank is full and radiators at full temperature, the boiler starts to switch on and off every few minutes. (And its not the stat triggering)

I've read about this problem before and many people in these forums have commented that its likely due to the pump, and that its not shifting the heated water and thereofre the boiler switches off to cool down.

How come in my case it only becomes a problem once everything up heated up. ( I have touched the radiators and they are VERY hot when the problem starts).

Although everything still seems to work, my concern that this stop/start issue will damage the boiler eventually.

Thanks for anyones help.

 

[bengasman]

It is supposed to do that, if not, it would be overheating

 

[The3]

Hi Bengasman,

Thanks for your reply. I know it sounds stupid.. but I would've thought that it would wait longer before restarting after reaching optimum temp. It just seams to be switching on and off every 3 minutes which seemed concerning.

I think the main problem i have is that the heater banks aren't large enough to properly warm the house, and that the radiators are reaching full temp constantly but the central thermostat isnt getting to kick in...

thanks