Hi Fitted a replacement gas fire yesterday. It wasn't new and had been stored for over a year.
One radiant seems to burn with a yellow flame compared to the rest. I switched the gas jet and radiant itself but there is no difference.
The gasflow is simple, a four holed jet to feed ach radiant a space [not adjustable] of around 15mm then a tube around 10mmwide by 30mm length that ends in a fine grid under the radiant.
Any thoughts on the subject would be very welcome
HN
A picture would help, but it sounds like it's not mixing air in with the gas. This is normally done immediately after the jet, which points into a tube with openings at/near the jet to draw air in. Something around there isn't working right, most commonly dust or debris in the air intake or mixing tube.
It's not safe to operate until it's been cleaned/serviced (and not just the one obviously faulty one, but the whole thing). The yellow flame means it's not burning properly, and could be giving off carbon monoxide and soot. Also need to check the flue, and that the ventilation in the room meets the manufacturer's installation instructions.
Gas fires rely on a fresh air duct to the burners, the duct usually runs from the knob end.
When the heat settings are 2-burners or 2+2-burners there is a duplex duct.
The most heavily used setting is often Low/Medium, which means that duct tend to get clogged with dust - particularly in a carpeted environment re long-hairs. In which case the burner with flicker yellow, burn yellow, and also burn tall. Heat output usually sucks (so it is wasting money), it is producing a lot of CO (as all gas fires do), and it is clogging the chimney with soot which will regularly fall down as marbles, is hygroscopic & pretty nasty to the mortar.
This is why in the old days, the proper gas fitters used to take them outside and soak the burner/ducts in a paraffin wallpaper paste tank. Those fitters are now usually Grid workers and occasionally will service a gas fire properly for someone, fed up with the common skimping.
If the radiants are broken, they are often not available. Missing sections at the rear of radiants can cause local hot spotting of the heat exchanger, which lets your CO producing appliance put PoC & CO into the room. This is why a gas fire absolutely should have a working CO alarm (and preferably a paper backup) in the room. Some like them also upstairs re buggered flue - as well as in the loft.
Check the heat exchanger at the back for distortion and cracks, quite a few units (Valor junk) tended to split the metal because it was too thin when run too much on High. It was the decline of the gas fire re cost v backstreet manufacturing practices.
probably traces of some metallic salt somewhere..or soot.
Many thanks for the help.
I do seem to recollect from school chemistry is was lack of air that made Bunsen's yellow.
Anyway I had a look at the offending tube. A spider must have set up home at some stage.
Thank's, I never thought to look inside the pipe. A gas air mix didn't strike me as being the right medium to cause an obstruction!!
One lives & learns!
HN
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