What is a suitably lined chimney

[Jon W]

I've just found out that I don't need to buy a balanced flue stove as I have a chimney (conventional flue). However in the brochure it uses the term suitably lined. The chimney is about 70 years old, brick, and is lined with cement (probably lime) which is now starting to flake off in places. The original chimney stack has been replaced with a aluminium pipe and cowl.

Now I may well fit the stove myself, as it looks pretty straight forward, or I may pay someone. Either way I will get the work comissioned by a Corgi reg person.

Bascially, I just need to know that if I buy this conventional flue model stove (efel harmony 5), that I won't need to spend another £xxx amount having the chimney specially lined.

It seems that I just need to stick a short length of stove flue pipe up the chimney, and make sure it's got an airtight 'closure-plate', and then let natural convection do the rest. Due to the small size of the stove (5kw output), it appears that I don't need a ventiallation hole either.

Sorry for rambling.

Advice/comments

Jon

[Christian McArdle]

One of the following websites will point you to a chimney sweep. The chimney sweep with clean, test and repair your chimney to the required standard and issue a chimney certificate that confirms that the flue is suitable for your purposes. They will also state if you need to get the flue completely relined.

Be careful, whatever the regs say, if you have no ventilation, then you die. If you have leaky sash windows and gappy floorboards on display to the underfloor void, then you won't have a problem. If you have sealed double glazing and no draughts whatsoever, you'll get CO poisoning. Don't rely on the gas fire's inbuilt CO detection. It may not work.

Christian.

[The Natural Philosopher]

If its that old IIRC you are permitted to use a flexible flue liner. If you are in suffolk area I have some of this going begging.

Building regs will not allow use of an unlined flue for stoves. Period.

You will. If BCO catches you. In any case its extremely stupid not to. The linetrs - flexible ones - will noi be too expensive: Fitting is harder as you tend to either have to haul them up to the pot or drop them down fronm it. Probably need to remove pot and replace with cowl anyway to sptop birds falling down. This means scaffolding or a brave builder up top on the pot.

Illegal IIRC. Stove pipe yes, but into that flexible liner.

Check with online building regs, and pleaee, don't skimp on it. Or call up BCO.

It will cost a lot - several hundred to have it done, maybe more. I fited an old wood burnetr to me new house, and I was required to use stainless steel double insulated liner EVEN THOUGH the flues were lined with ceramic liners. Cost about a grand with labour. You won;t need to go that far, but even so expect £500 and be grateful if its less.

Old chimenys seem to be reckoned tobe good from fire point ogf view - hence the allowance of a single steel liner that gets very hot - but are not deemed to be gas tight - and mostly they are not. CO poisoning is a nasty way to die. Do it properly.

As far as ventialtion goes, you will need a little bit. Something like a hit and miss cvent in the room is adequate.

Again, consult BCO before starting. Unless you reckoin you can keep them out of the picture altogether.

BCO regs are very sane on fire and combustion appliances: I would stick to the guidelines no matter what the cost, especially if you want your insurance to stay valid.

[Jon W]

Thanks, for that, very informative.

But does all that apply to a natural gas stove, if so it'll probably be cheaper to get the balanced flu option. It's about £200 extra, but no fannying around(sp) with chimney/flu liners or ventillation holes.

Jon

[anthony james]

I'm investigating the same thing at the moment - looking for a Gas stove to put into the fireplace in a london Terrace (probably 120 years old). I'm pretty certain we'd need the chimney relined (or more likely a flue installed inside it).

I'm starting to wonder if we would be better getting a balanced flue model and just venting it through the back of the chimney to the gap between us and next door rather than getting a flue put up to roof level. we could then just 'seal' the chimney. Fitting would certainly be easier (and probably cheaper) - are there any disadvantages?

[Christian McArdle]

Your neighbours might not want your gas combustion products in the shared passageway? Apart from that, I can't see much of a problem. Indeed, they have an advantage in not requiring additional room ventilation, which can reduce energy efficiency.

Christian.

[The Natural Philosopher]

It almost certainly would be, except prefer if at all possible to get combustion products up high.

Call your BCO up and discuss. He will have accurate regs to hand.

[Dave Liquorice]

Thought gas fires had oxygen sensors rather than CO. A fire will use the oxygen from a room down to much lower levels than a human can tolerate.

[Ed Sirett]

Quite the primary lines of safety are correct combustion, adequate air supply and a sound flue to remove products of combustion.

This is a second line of defence, tha aim is not sense when there would be insufficient oxygen to support life or combustion but to sense when there has been some depletion of the oxygen enough to endanger life and turn the fire off.

[The Natural Philosopher]

Ed. by removing the extra words, your sentence reads as above.

Frankly, I can't see what you were driving at...If life is endangered, its insupportable?

[Dave Liquorice]

'Tis a bit of mouthful but as O2 levels drop you will become unconcious but if returned to normal O2 levels you'll recover. Your life has been "endangered". If the O2 level continued to drop there would become a point where you would die because there is not enough O2 to support (your) life.

[Ed Sirett]

I expect the CO would get you first long before the lack of O2. And before that you would probably say something like, it's stuffy in here let's open the door/turn off the fire.

The device might help someone who is sleeping I suppose.