combi boiler - does it need to be on an outside wall?

jackieb

We're in the process of getting plans drawn up for a one storey extension. At the moment we have a 13yo back boiler but we'd like to change it to a combi. Right now it's in the livingroom in the fireplace. The best place for a new one would be in a utility room we're making out of our present kitchen, but once the extension goes up it won't have an outside wall.

It might be a stupid question but does it need a flue? Could it be redirected so it went out of the roof of the extension? If we fitted it in the kitchen it could be on an outside wall, but i'd prefer not to have it there.

Canucklehead

Hi

You do need a flue.
It can be run in just about any direction you want.
If vertical up through the roof is your choice then you can go about 10 metres.
It varies from make to make but most will be more than enough for your needs.
However .. each extension for the flue will cost you £25 roughly, that would be for 750mm . A long flue could cost nearly as much as a boiler!
HTH

Corgi Guy.

HugoSP

If you're getting an architect to draw up plans for the extension then he should be able to specify a verticle flue boiler.

The inlaws have one and, athough the boiler is on an outside wall, they like it going through the roof as it negates the need for a flue at the front of the house.

There are combi boilers on the market with verticle flues.

Yes you do need a flue!

bob_a_builder

Not sure if its the only one but

"The C36 Combi uses any standard (muPVC). kitchen waste pipe system as a flue that can run up to 20m and longer flue lengths, up to 60m, are possible using Keston’s own 75mm flue system. This allows almost limitless boiler installation possibilities.
"

LINK

jackieb

Thanks everyone.
If we put it in the utility room it won't have to be redirected very far to go out of the roof of the extension - probably less than 6ft. We do have an architect to draw up the plans. He's coming back this week with some drawings. I'll mention it to him then.

jackieb

Another question - sorry. It would mean that the pipes would go horizontally and then vertically. Is that still possible?

Canucklehead

Hi

You can do that.
Every 90 degree bend that you use takes 1m off the total allowed flue length or .5m for a 45 degree bend.(this might very slightly with manufacturer.)But you are well within the total length by the sound of it.
Corgi Guy.

jackieb

Thanks. You've put my mind at rest. It's funny how you worry about something if you don't know anything about it. Ignorance isn't always bliss.

amanda40

When we changed from Back Boiler to Combi - we were getting kitchen redone at same time. We opted to put boiler in the attic, to save on space in the kitchen. We have a flue going up through the roof. The controls are down stairs so it works out fine as as it can be a bit noisy keeps that out the way too.