Potterton Neataheat Profile not heating

[RolyBoy]

Hi.

I have a Potterton Neataheat Profile 60e.

Just recently I have noticed the radiators are not heating anywhere near as much as they were last year.

The boiler is firing up the same as always, but it seems to cycle around the 1-2 mark on the boiler control thermostat - it seems to make no difference where on the dial the boiler stat is set, you can hear it 'click' off if I rotate the stat towards the off position at about 1-2.

Last year I had the stat set at 5-6 and whilst heating I could turn the dial down and it would click off almost immediately, and the rads where a lot lot hotter.

I know it's not a problem with the overheat switch as the button underneath is not popping out.

Any suggestions gratefully received as it's getting real cold in the house!

Thanks thanks thanks.

 

[AlanE]

Pump not working properly is first thought.

 

[RolyBoy]

The pump appears to be working ok, its spinning and speeds up/slows down when the speed switch is turned. I've no idea how to check it's not doing what it should....