We bought our house about 6 months ago and has a fairly new boiler. It also has a gas fire in the lounge. We got around to servicing both last week and all fine etc.
The previous owners had blocked off the chimney with a bag full of paper in the lounge. We had assumed to avoid soot/dirt coming down or a draught. We never did this in the old house. We never changed anything until we got it checked and with the cold weather we got the fire going.
So... advice/opinions:
1. The fire warms the lounge a treat
2. There has been a draught under the lounge door since we unblocked the chimney and/or used the fire
3. The hall has been colder - but there is no draught under the hall door due to the outer door.
4. Stopping using the fire (always a nice to have) the draught reduced.
5. Stuffing the bag back up the chimney the draught stopped and the hall is warmer again - so assume the chimney was sending up a lot of warm/hot air, the air from the hall being drawn into the lounge, and the air in the hall came from the ventilated cellar.
Options:
1. Leave the chimney blocked most of the time
2. Work out how to avoid the thermal loss up the chimney
It seems ironic the house could be colder with the gas fire on.
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I take it that the gas fire is a flueless type and does not "need" the chimney.
We once owned a house with the stairs in the lounge, never again, all the heat went upstairs and as the thermostat was in the lounge the heating was usually "on" trying to maintain the lounge temperature.
Last edited by: Old Navy on Tue 28 Dec 10 at 08:52
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My situation is that I have a Straxgas coal effect fire in the lounge with an 'open' chimney + 2 large double rads in the room.
The Straxgas is quite efficient, compared to some gas coal effect fires, and will heat the room without the central heating being on,
What type of gas fire do you have - is it a flue -less jobbie? if I blocked up my chimney, I'd be up the bone yard by now!!
A gas or solid fuel fire needs oxygen to live (like moi), when my central heating goes off at 9-00pm, I can feel cooler air being drawn across the lounge floor from the hallway so I would assume (in my case) that the air brick has been blocked up many years ago and so I always leave my lounge door ajar for that very reason.
If in doubt - get it checked out by a gas-safe engineer mucho pronto.
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>> If in doubt - get it checked out by a gas-safe engineer mucho pronto.
>>
+1 on that. Although the OP does mention that he had the fire serviced, which unless I'm mistaken would involve the engineer checking the adequacy of the ventilation.
Last edited by: Harleyman on Tue 28 Dec 10 at 09:50
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>>A gas or solid fuel fire needs oxygen to live
>>
Many years ago we had a near miss when we did not allow enough air to get to an open flue bathroom "Ascot" . IIRC you now have to have a vent in a the door with such an arangement.
You have to get it right or risk being an ex poster :-((
If you have solid floors then maybe an airbrick above the skirting board adjacent/ near to the fire ( assuming there is an outside wall nearby ) ?
My 1930 house has the original brick fireplaces and these include small brass louvre vents set in the outside brickwork of the hearths, just above the carpet. These allow air to be drawn from under the floor and vastly reduce air being pulled across the room.
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Shirley a fire gets all the air it needs via the open chimney? although I'd still never close the lounge door.
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All thats required is a suitable vent for fresh air and oxygen, near the fire. The provision of such should have been checked when the fire was checked.
If you then have fresh air being drawn in from somewhere else in the house in sufficient quantity to feel a temperature change, you need to stop the source of the cold air.
Dont however prevent the general circulation of air withint the house, or damp spots will appear.
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Our very first house had open tread stairs rising out of the lounge.
Three disadvantages: the heat does, indeed, escape; noise travels spectacularly; muck and bullets fall through the treads depositing detritus on anything underneath.
What a mistaka-to-maka: never again.
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It's 14 years since I've had a gas fire r :-( but when we did have one the draught use to whistle under the living room door, no exaggeration. We changed it for an extremely efficient one that claimed to have all sorts of baffles between it and the chimney, which it needed for ventilation. It made a huge difference, though there was always a draught into that room.
So - it may be the type of fire you have.
John
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Ours is an open coal effect gas fire - so the flames come up between the fake coals. The fire was taken apart, cleaned, reassembled and checked by the gas engineer.
When the chimney is blocked there is no draught coming under the door. With the chimney unblocked there is a draught. This is worse if the fire is on.
So heat is escaping up the chimney - I can see how a lot of the heat from the fire goes that way. But there is a draught even when it is off.
The bag is now back up the chimney and the hall is warmer. The only source for the cold air into the hall and then into the lounge is from the colder cellar.
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>>The only
>> source for the cold air into the hall and then into the lounge is from
>> the colder cellar.
>>
How? is there no door to the cellar?
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It's "oop north" Zeddo - coal in the bath etc :-)
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Hot air going up a chimney will suck in air from the room, as you have experienced.
All the (sealed) gas fires I have fitted (3 of my own) have come with a plate to block off the chimney. That plate has a 2" by 6" or so slot in it to take the rectangular 'pipe' coming out of the back of the fire. That does not completely seal the fire flue to the chimney because the lower half of the fire back plate allows air to enter from the room and flow up and through the 'pipe' into the chimney. It is as if fire designers want to suck away air from around the lower back of the fire. But also, of course, it reduces the suction in that pipe on the flue gases and allows the fire to burn more naturally and so extract more heat before the gases go up the chimney.
Having the chimney aperture sealed with a plate except for the slot, is the best way of minimizing your heat loss.
Another is having a modern central heating boiler with its external concentric dual pipe that both exhausts the flue gas and supplies the air needed for the burner.
Old boilers used a flue that was not sealed. Mine had a 4" vertical pipe that was open at the bottom and the boiler gas went into it via a T junction about 12" up from the open end. That open end sucked in so much air out of the room that even the regulation air vent of so many square inches was inadequate to stop my gas fire flue gases (in an adjacent room) from coming back into the room on some days of the year when the air was damp and heavy, unless a window was open. (I could feel the hot 'air' spilling out of the back of the fire). The problem vanished after a modern boiler was fitted.
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>>That open end sucked in so much air out of the room that even the regulation air vent of so many square inches was inadequate to stop my gas fire flue gases (in an adjacent room) from coming back into the room<<
Reminds me of when we lived in a barn perversion with an 'openplan' lounge/dining room/kitchen with a multi-fuel stove at one end, and an extractor fan for the kitchen at the other end :(
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>> How? is there no door to the cellar?
Of course it does Z ;-) But there's a tiny bit of a gap which I'll sort out. But the draught under that is tiny. The amount of colder air being drawn under the lounge door was noticeable. And the hall was a lot colder.
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I might have got the wrong end of the stick here, but unless your fire has a separate flue you can't be using it with the chimney blocked, or you wouldn't be posting?
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I've a gas fire with a gas, back boiler in the lounge and I too get a draught of cold air at floor level. The vent is about twenty feet away in the dining room.
I toyed with the idea of cutting a trench in the concrete floor to the outside wall closest to the boiler and trunking air closer to it. A gas fitter told me that wouldn't be acceptable as they like to see the incoming air passing the length of a room.
I put my feet up on a pouffe.
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>>I put my feet up on a pouffe<<
David Laws?
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Blocking a flue completley will probably lead to condensation.
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"I put my feet up on a pouffe.'
I wondered why Iffy wasn't posting.
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>>Gas engineer
No he wasn't.
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My apartment in Austin had a 'flue shutter' which was a metal flap installed in the chimney which was quite effective at stopping both warm and cold draughts.
I don't suppose we'll ever see them over here - couldn't trust the average Brit to operate the lever before lighting the fire could we?
Kevin...
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>> I don't suppose we'll ever see them over here - couldn't trust the average Brit
>> to operate the lever before lighting the fire could we?
>>
>> Kevin...
>>
Since it was in Texas, are you sure its purpose wasn't to let the hot air out? ;-)
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Gas fires, chimneys and draughts... - Old Navy
