Boiler not condensing

janja

I recently fitted a Warmflow high efficiency condensing boiler, there seems to be lot of vapour coming out of the manifold and it is not producing any water. I have checked for obstructions in the trap. Any other ideas please?

ntpm

janja wrote: »

I recently fitted a Warmflow high efficiency condensing boiler, there seems to be lot of vapour coming out of the manifold and it is not producing any water. I have checked for obstructions in the trap. Any other ideas please?

Not too sure if you are a plumber or end user so just an overview:

Condensing boilers only "plume" or "condense" when operating under certain conditons.
Depending on your temperature controls and heating system design the boiler may be running the majority of the time in "non-condensing mode":eek:.

Science behind it basically is when the return water temperature and flue temperatures are at correct values... then water vapour in flue condenses.

The water vapour will usually pass up through the flue to atmosphere. Some may condense on the heatexchanger or flow back down the flue. This is why you need a condensate pipe.
If the condense pipe and trap has some water in it then the boiler is/was condensing. The trap will allow additional amounts ( even a small drop) to drain away as condense as it is being produced.... you may not notice it.

kscobie

Make sure the trap is primed , the boiler passport will need to be completed , and if it has to be done yet, get the engineer to ensure the boiler is sized correctly, if its oversized, it may not condense or plume

janja

Thanks Guys for the info.... How do you prime the trap?

kscobie

i know this sounds wrong, but the handy way is to pour a half pint of water down the flue, it will backfill the trap

crosstownk

If the water returning to your boiler is above a certain temperature, then it will not be in condensing mode.

Some info here might help.