Update: Living flame gas fire cutout

[Stuart]

Just wanted to update those of you who remember me posting about this, and a big thanks to Ed and everyone else for their input.

My problem was that my DFE fire was cutting out after a few minutes of use.

When BG visited to service my boiler I got one of them to look at it briefly and (aside from banging on about the ventiliation inadequacies) he also said that the pilot flame seemed too small (I think Ed mentioned it needs to envelop the thermocouple).

So off he went. A few days later I decide to have a look-see myself. Pilot light outlet simply pulled off the gas jet without too much force. I gave it a good blow and clean with a toothbrush, and also the gas jet which didn't look too bad. Put it back together and when I lit it the pilot is now massive!

Fire stays lit all night, so job's a good 'un, only took 20 mins to do... unfortunately the nonce that fitted the fireplace (before I moved in) didn't fit the grill properly so I spent the best part of 2 hours with my head in the chimney trying to get some tiny nuts on the end of the short bolts that came with it. :/

Just one thing: do you think I should get an air vent/brick fitted? BG quotd £60 (but not sure how ugly it looks), I was told it needs to be

125cm2 in diameter, which seems potentially drafty to me. I know the fire is classed as 'at risk' by BG because it's not an inset one, though the pull on the flue is fine by all accounts, I just don't know really.

Cheers,

Stuart.

[Andrew]

In article , Stuart writes

I quote from Approved Doc J

3.11 Flued Decorative Fuel effect (DFE) fires.

Any room or space intended to contain a DFE fire should have permanently open air vents as described in (a) or (b) below unless the installation is in accordance with 3.12

a) for a DFE fire in a fireplace recess with a throat, the air vent free area should be at least 10,000 mm3 (100cm3)

b) for a DFE in a fireplace with no throat, such a fire under a canopy, the air vent free area should be sized in accordance with section 2, as if the room was intended to contain a solid fuel fire. (Table 2.1)

3.12 Permanently open air vents may not be necessary for DFE fires with ratings not exceeding 7kW (net) that have been independently certified as having a gas flue clearance rate (without spilling) not exceeding 70m3 /hour

Table 3.1 Fire type Min Flue needed Radiant /GAs fire New flue 125mm diameter or 16,500 mm3 and min dimension of 90mm Existing Flue 125mm diameter or 12,000 mm3 and min dimension of 63mm Both usually referred to as a class 2 flue ILFE or DFE within a fireplace opening up Circular or Minimum flue dimension of to 500mm * 500mm Rectangular 175 mm - i.e. usually referred to as a Class 1 flue (1)

DFE fire installed in Calculate according to Para 2.1 IN section 2. fireplace with an opening in excess of 500*500mm

(1) Some DFE appliances require circular flue of at least 125mm diam.

------------

2.1 Air Supply to Solid fuel Appliance

Type of appliance Ventilation Open appliance, no throat under canopy (inc. gas DFE) Open air vent with free area of at least 50% of cross sectional area of flue

So it is possible that the BG engineer hasn't told you the truth - you could actually need more than 125 mm diam vent, if the fireplace opening exceeds 500*500mm.

PS DFE fires typically give out 1kW heat for every *10*kW gas burnt. This is why they need big vents. In fact these vents could even make the room colder than the 1kW heat output !. I take it SWBO made the decision to fit the silly thing in the first place, or have you been advised by an estate agent or Ms Bling Bling Beeny Beeny ?.

[RichardS]

Dunno if this helps, but when I had my fire installed it had been specifically built to be 7kW so as not to require additional room ventilation.

When the fitter came and installed it, though, he commented that the ventilation did not necessarily have to be an air brick, and a couple of permanently-open louvres installed into the (well ventilated, suspended wooden) floor would have met the requirements and meant that I could have had the full output fire.

This obviously requires that you have a suspended fllor which is also ventilated, and i am sure that others will be able to confirm or deny whether this would meet the regs, but it could be an easier way and perhaps decoratively more acceptable than an airbrick into the room.

If I had installed these vents I would have also screwed a notice to the underside or tacked one on so that it was visible when the vent was removed so that any "improver" in the future was aware that the vent was there as a vital part of the gar fire installation, just in case their S/HWMBO had demanded the removal of the "ugly" vent... (such demands are put upon me regularly!!!).

-- Richard Sampson

email me at richard at olifant d-ot co do-t uk