potteron promax HE33 plus

I have a 13 month old Potterton Promax HE 33plus. When the hot water is called for the flame ignites then increases. As it increases the fan speeds up then the flame goes out. This all takes 2 - 5 seconds and keeps repeating - water will not get hot. If I turn the tap down and the water temp down on the boiler I can get the flame to stay on but the water is no good for a bath.

It does this but only twice when the CH comes on then manages to regulate itself. A NTC sensor was replaced when it was a month old. The DHW NTC sensor weaps. Is it the DHW NTC or a further major problem? If a major problem then I must call someone in.

Any ideas gratefully accepted?

Does the flame lift of the burner just before outage ?.If so try to run the boiler without the combustion panel,if it runs o.k i would say you have a flue problem.

Thanks but we have tried it without this panel and still does the same.
Also yes the flame does lift from the burner.

We can actually trick the DHW.
If the CH is on and the flame is on, and then we turn the hot water on full the problem does not occur.

I am going to try a new NTC sensor on the DHW side. What do you think?

Many thanks

If the flame lifts off the burner then its normally as a result of a too weak mixture.

However to set the mixture properly you need a flue gas analyser amnd that usually comes with a CORGi owner.

Tony

If the flame is lifting off the burner i would be investigating why.......

Marcusboiler,

I see you've had the panel off the combustion chamber which I personally wouldn't recommend but anyway... Please don't go trying to adjust this yourself. As Agile states, you need a Corgi. He/She knows what he's doing. You may feel confident about doing it but it could all end in tears as my dad used to say!