Baxi 105e heating not adjusting from the dial

Hi Guys

I have a issue with a Baxi 105e CH not adjusting on the dial, the hot water is fine.. You can set it too max, and it will heat to max, but when i would turn it off within the first 2-3 seconds the burner would cut out and it would start to cool, but now it stays on max... If i set it too half way on the dial and it sits comfortably there, then i switch it all the way round to max nothing changes.. It seems to have a mind of its own.. i have no confidence it switching it on through the night, you it can fire up fine and warm up, you get up in the night and its freezing because its decided to cool down, although the dial is in exactly the same place?

Im now at a point if its on low and i want to turn it on to max, i switch it off, turn the knob to max and reset the boiler. when i comes back on it will heat to max and stay there.. if i didn't reset it, then it would stay on low no matter of CH dial adjustment position.

Thanks

 

If the lights indicate the increase or decrease of temperature ( it is not super fast- takes time) then I would suggest you stop twiddling the dial as anti cycling circuit will delay the action of boiler firing