DIY Doctor UK DIY Forums

Hi,
I have a Black Beauty Radiant Gas Fire (Model 340) purchased and fitted new in October 2004, although it has probably been used for less than 12 months since then.
The problem appears to be that as the 'control knob' is moved from IGNITION setting 1 to setting 2 there is a 'snap' sound (at the gas tap) which seems to mean that the 'electromagnetic valve' is shutting off the gas supply at that stage. This is part of the integral 'Flame Supervision and Spillage Monitoring System' in which the gas supply shuts off automatically:
a) if the 'pilot flame' goes out, or,
b) if there is insufficient oxygen due to:
(i) spillage, or,
(ii) lack of ventilation.
There is no reason to suspect a 'lack of ventilation' as the flue was brand new when the fire was fitted and the flue restrictor is in the fully open position.
There is also no reason to suspect 'spillage' as the closure plate is well sealed and there are no extractor fans etc. in the room.
This leaves the 'pilot unit' as the most likely source of the difficulty.
QUESTION 1)
In normal operation, should the 'pilot flame' go out when the fire is operating at 'control settings' 2 thru' 5 or should the 'pilot flame' remain lit at all times?
QUESTION 2)
If the latter, what might cause the 'pilot flame' to extinguish itself as the control knob is moved through the settings from IGNITION 1 to 2 and beyond thereby triggering the 'electromagnetic valve' to shut off the gas?
QUESTION 3)
Otherwise, can anyone with knowledge of this type of fire throw any light on what might be causing the fire not to function as soon as the control knob is turned from IGNITION setting 1 to setting 2 or beyond?
QUESTION 4)
The fire now costs about £180.00 new plus fitting. Does it sound like an economically repairable proposition?
Many Thanks,
DAVE
:(

It's probably the pilot flame isn't strong enough, when you turn the control up - more gas goes to the main burner, have a look at the pilot flame - it'll more than likely lift off the thermocouple.

Try cleaning the pilot, and the sensing tube (back of fire heat-ex) if that doesn't work you will need an RGI to clean the pilot supply pipe and check the gas tap for blockages.

The pilot is the flame supervision device, this will stay on the whole time the fire is lit - as soon as the pilot flame lifts off or goes out - there's no electric current being made and the electromagnetic valve will close - shutting off the gas supply.

htg

To htg engineer,
Thanks for your reply.
- You are correct about the pilot flame lifting off the thermocouple as the control stting is increased, hence the complete extinguishing of the fire.
- I have previously tried cleaning the pilot.
- I don't know how to identify the "sensing tube" but will take another look.
- Otherwise, I will consider the other option of getting the gas pipe cleaned out.
Thanks,
DAVE

Sensing tube - normally a silver tube that will connect - or be very close to the pilot and will go up behind the fire to just under the spigot.


htg