Central Heating boiler producing condensation

[johncrook]

Hi, I have a 'normal' central heating boiler i.e. not condensing type or combi. Boiler is 2 years old and has been running fine. Had the boiler serviced about 2 weeks ago and since then it is producing about 1 litre of water , assume it's condensation . The water comes out of a pipe that is connected to the flue just above the boiler. Have spoken to the plumber who insists this is not a problem, and caused by condensation around the flue which he says may need packing around it with Rockwool to reduce the problem. I am not convinced as this only started happening after it was serviced. Under sufferance he is coming back next week to have a look. Any suggestions or advice would be much appreciated.

Thanks

[Jason]

Around here it only really started getting cold about two weeks ago. Could the problem have started with a change in weather conditions, that happen to coincide with the servicing?

-- JJ

[johncrook]

Hi, yes could be about the same time, but if that means it is condensation from the flue how come it never happened before ??

[Michael Chare]

Packing the outside of a stainless steel flue liner with vermiculite will help to keep it warm and prevent condensation.

[Doctor Drivel]

The boiler should be set to 80C. What is it set to? The flue should slant downwards towards outside, so that any condensate that occurs drips outside.

[Doctor Drivel]

If it is fitted properly and the boiler set to 80C, then no condensation should enter the room. It will drip to outside.

[johncrook]

How do I tell what temp the boiler is set to ? Dial on the front has no temperature markings,,,,,,,,,,,,,,cheers

[Doctor Drivel]

Turn it to maximum. Non-condensing boilers should always be on maximum. What is it set to?

>

[John]

If they should always be set to maximum, why is there a Minimum setting? I tend to have mine set at Minimum because it seems to switch itself on and off less: if set at maximum it seems to get too hot too quickly, and cycles its On/Off state.

John

[Ed Sirett]

In my experience the only non condensing boiler with a significant problem with condensation is the Ideal Response and by implication other models with premix burners that are not condensing models.

There are a number of possible causes of condensation it probably needs a few of them to conspire together.

1) Very cold and damp weather. Very cold weather is also usually very dry. 2) A longe length of uninsulated flue, twin pipe type is usually fine. 3) Boiler set to minimum although minimum is probably around 60C 4) Some problem with the ventilation/ air flow through the boiler. 5) A boiler that is under sized and struggles to get the primary up to temperature.