Boiler firing almost continually

[Bobbee]

My Potterton Suprima 60L fires almost continually. It does shut off every few minutes, the pump runs on a bit then stops and three seconds later the pump starts and the boiler fires again. this happens however many rads are calling for heat. We have thermostatic valves on all radiators except the bathroom but no room thermostat. Is the problem to do with the lack of a room stat?

[htg engineer]

Do the radiators or hot water get too hot ?

If it does then you need the thermostat checking - the constatnt running of the boiler may just be because of the drop in temperature as it has been quite cold over the last few weeks.