Gas Fire / Ventilation advice

[Wurzel]

Further to the utilities thread and cutting fuel bills, when my house was built it had a gas fire (never saw it but guessing some kind of sealed in unit) with a back boiler . This necessitated a (very drafty) vent in the outside wall, I'm guessing to prevent any chance of roomful of oxygen being burnt and not replenished. The back boiler was removed before we purchased it and replaced with an open flame gas fire (which we rarely use as room has radiators) which exits through the same chimney flue as the back boiler would have done.

 

Question : Can I seal over the wall vent permanently or would it still be needed when such a fire is being used? I'm thinking as it's an open gas fire then oxygen can still enter room via the flue but could be a drastic mistake if I'm wrong.

[Grim Reaper]

I am a gas safe registered engineer by trade, you must have 100 cm 2 of free air available for a dfe gas fire (decorative fuel effect) no fly screens or sliding shutters. It's not all about combustion air but also used for flue/chimney pull. In my opinion they are massively inefficient ie circa 20 percent I wouldn't use one in my home the way gas prices are going. Better off capping off the fire and sealing the drafty vent up and getting another focal point such as an electric unit, if in doubt consult a gas safe engineer.

[Ohio Saint]

My only advice would be to not look for advice like this on a footy forum.

[Wurzel]

I am a gas safe registered engineer by trade, you must have 100 cm 2 of free air available for a dfe gas fire (decorative fuel effect) no fly screens or sliding shutters. It's not all about combustion air but also used for flue/chimney pull. In my opinion they are massively inefficient ie circa 20 percent I wouldn't use one in my home the way gas prices are going. Better off capping off the fire and sealing the drafty vent up and getting another focal point such as an electric unit, if in doubt consult a gas safe engineer.

 

Cheers for the reply. The fire is a nice feature but very very rarely turn it on (room has 2 radiators in). It doesn't matter how high the flames go it doesn't seem to generate any heat in the room, so I can well believe your 20% figure. The vent is about 7ft up wall approx 9 - 10 ft away from the fire so much further away than your 100cm². I could easily block up vent and retain fire for decoration (although probably get a downdraft from flue as well) and never use it but would that be breaking any regulations and/or cause problems if I come to sell house?

[PhilippineSaint]

Cheers for the reply. The fire is a nice feature but very very rarely turn it on (room has 2 radiators in). It doesn't matter how high the flames go it doesn't seem to generate any heat in the room, so I can well believe your 20% figure. The vent is about 7ft up wall approx 9 - 10 ft away from the fire so much further away than your 100cm². I could easily block up vent and retain fire for decoration (although probably get a downdraft from flue as well) and never use it but would that be breaking any regulations and/or cause problems if I come to sell house?

 

 

If you did that and then sold the house then the subsequent owners had problems IE died through asphyxiation due to incorrectly installed gas fire you would be liable to prosecution for manslaughter at the very least.

 

Let a professional inspect it and carry out any modifications required for it.