Combination Boilers - noise and smoke

[NewDiy]

I am considering changing hot air central heating to wet system and have been quoted by British Gas (going to get other quotes!) for condensing boiler (not combination). I am wondering how bad the plume of fumes from these boilers really is and whether they make any noise (gas engineer said they have a fan?). Many thanks for any information. I quite like the hot air system apart from it is a little noisy and I am concerned that these are not very popular should I wish to sell the house in the future.

[NewDiy]

Sorry title should have been CONDENSING BOILERS

[Tony Bryer]

Go on, shock us.

It's steam, not fumes - no danger. If it's likely to be a problem, discharge at a higher level

The fan is unlikely to trouble you unless you have the boiler in a particularly quiet location (e.g. bedroom)

[John Rumm]

A reasonable photo of one in action here:

of a kettle boiling fast, and you get the idear. It will be worst when the boiler is working hardest - e.g. system warm up etc. Once up to temp and the boiler can modulate down the plume will diminish qite a bit.

Most current boilers will have forced air induction - so you get some fan noise. Some makes are louder than others. Modern modulating boilers are quieter since the fan speed will get lower for lower heating rates.

[Shokka]

airA reasonable photo of one in action here:

there's a house near us with a condenser boiler and on certain cold days it pushes out *tons* of steam! This is usually on a cold morning when their CH fires up for the first time.

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[Mary]

I know nothing about "hot air" and "wet" systems but if you are getting a new gas boiler I think you will need to get a condensing boiler given building regs now. They all have fans, but some are a lot noisier than others.

Don't get a Keston condensing boiler - they sound like jet engines taking off and are completely unreliable.

Worcester Bosch are meant to be quite good.

Try

for a reasonable quote and decent work if you are in NW London or the counties on that side of town.

Mary

[NewDiy]

Thanks for all the information. Might have to re-think this one - maybe the hot air system is not so bad after all. The vent for the boiler would come out between the back door and a window which does not sound good.

[Doctor Drivel]

What is wrong with the forced air system? They can always be uprated.

[John Stumbles]

No it's actually mist (a cloud of very fine water droplets, like clouds in the sky, mist or fog) not steam. Steam is (a) 100 degrees C or hotter (b) invisible!

[John Stumbles]

Is that a problem? It's only water after all. However many boilers have 'plume management' options for their flues. Typically these are a periscope-like extension to the flue part of the concentric flue-outlet/air-inlet business which goes from the boiler to outside, and discharges the misty plume higher up and (hopefully) out of the way.

[Andy Hall]

Really?

Does a big lorry come and cart it away?

[Owain]

I think the plume is quite pretty. Conventional boilers 'plume' in cold weather anyway.

Provided the flue is sensibly sited, I wouln't worry about it.

Of course, I'm not the typical house purchaser.

Owain

[Stephen Howard]

Is that true for oil-fired boilers too? One's been installed in next door's outhouse - the vent fires towards my back yard.

Regards,

[mogga]

airA reasonable photo of one in action here:

Round here they all seem to be being put upstairs or in the roof space...

[Doctor Drivel]

I have seen a few in the loft and the flue taken into the chimney breast. It gave the impression outside that a coal fire was burning as the chimney poured out "smoke". It looked very effective.

They look OK when the exhaust is via a vent ridge tile.