In article , Stuart
writes
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.
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
other types not relevant

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 ?.

--
Andrew