- This topic has 4 replies, 4 voices, and was last updated 21 years, 4 months ago by
Selgas.
-
Posts
-
-
Kiwi
On this combi-boiler my children have the habit of turning on the hot water and, in the few seconds it takes for the gas to light, to then switch off the hot water. Sometimes this means that the gas will ignite at the point it is shut off and will blow out the pilot light.
What can be done to prevent this? (Can the gas flow to the pilot light be increased to give a stronger flame?)
sbp
-
It sounds like the pilot is being blown out when the burner flame shuts off, creating a sudden draft in the combustion chamber. That it happens only when the burner is turned on and then off quickly suggests that the cause is a “plug” of cold air in the vent/chimney. This presents a resistance to the vent gases and the plug acts sort of like a piston creating a backdraft when the burner turns off. With longer running times, the vent gases get hotter and the flow out the chimney unobstructed, and when the burner turns off there is no backdraft.
I suppose that you could correct the problem by running more gas to the pilot, or maybe repositioning it. However, this is not something that an inexperienced person should attempt.
Unless the pilot is clogged or improperly calibrated, the problem you describe should not occur. The venting of gas fired appliances is designed to prevent pilot blow-out by downdrafts. Water heaters should have a vent hood or a barometric damper, both of which are indended to prevent just the sort of downdraft that you describe. Also the vent pipes must be properly sloped. Make sure that your venting system is adequately laid out and has a vent hood or damper (and the latter must be properly adjusted). If the installation is fairly recent (last couple of years), you should call back the installer and have him check it out (for free…since this is clearly a malfunction of the setup).
NtP
-
Your problem is aptly answered by Nick, however I would suggest if this appliance is older than 3 years of age then it is likely that the pilot assembly and for that matter the main burner is well overdue for a general service and check. In doing this your Corgi Registered Gasfitter will be able to correct the problem you are experiencing.
Spend a few pence now and save yourself considerable Pounds later.
Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians -
The Vaillant VCW Sin 18 is circa 15 years old, and is indeed in need of a good service and re-setting up.
I am based in the Loughborough area. Are there any suitably qualified/experienced people who know about Vaillant boulers of this vintage? Or are the Vaillant men themselves the best. How much would you expect the service/set-up to cost (Vaillant charge a minimum of circa £90-100 before they ring the front door bell, as you may know).
-
SPB
Sorry chappie can’t help you with what you are likely to be charged for that kinda service over there in Pommie land – down here I would expect to charge $50-$60 and it should only take a hour at most.
Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians
-
- You must be logged in to reply to this topic.
