We have a Glow worm Space Saver 50BF Cat11 (GC No 41 315 27) installed 1/11/79. The pilot light has gone out on two consecutive mornings. As the thermocouple had not been changed for 10 years this was the first job to do. A new SK2674 was purchased and installed. The pilot light ignited straight away however after 90 seconds the gas valve dropped and turned off the gas to the burner and pilot light. The pilot light can be re-ignited again after 3 minutes but once the burner fires up again it will always go out again after 60-90 seconds. As the Space Saver is such a basic boiler the only conclusion I have is the Maclaren gas valve is faulty. Although the boiler is 33 years old it is still in very good condition and up to now been very reliable. So if I can I would like to save and repair it. Do you agree with my conclusion or have you any other ideas to what is causing the problem. Many Thanks.
Good clean and hoover and changed the thermocouple
Hi I am Rick, UK Plumber, and I specialize on Boiler problems, I think it is more likely to be a gas/air mix problem, have you examined the flue completely, especially the inner section, if it has perforated then this will cause insufficient air and pilot flame lift off, if not this, or air intake obstruction, then a poor thermocouple connection at the gas valve, or even a bad thermocouple (I have had two this year), Rick
Thanks for the reply. The inner section is clear and the outer ( air intake) had a few small dried up dead leaves which were hooved out. What do you mean by a poor connection, the nut screwed in firmly with no leakage. The T/C was a new Glow worm product.
Relist: Incomplete answer.
The thermocouple connection is an electrical one, it does not "leak" corrosion or dirt in the connection can cause a problem as on any electrical joint, the fact it was a manufacturers part is not material, it can still be bad, I did fail to mention the strength/size of the pilot, the jet could need cleaning, the gas valve is most unlikely to be at fault unless water has contaminated the electric connection very badly (where the T/C connects) if the pilot stays lit when the main burner is not activated then it points to some thing other than the pilot or T/C, to discover what the pilot needs close examination as the burner lights and how long after the pilot fails, colour of flame etc. Rick
Thanks for your answer. My husband's asked me to let you know he'll look at it again in the next 24 hours and let you know what happens.
Thanks for your comments. I have again tonight checked what happens when the burner is activated. Please note that when I cleaned the boiler and flue, I also disconnected the pilot light and cleaned the jet. The pilot light is deep blue and the T/C glows red. When the main burner ignites their is a strong deep flame flame and you can see the pilot light graduley get smaller until it finally goes out, and within 10sec the gas valve closes. From ignition to lock out is about 30sec. I think there is a screw on the Maclaren gas valve which can increase the pilot flame strengh but which one I am no sure. Do you have any ideas?
OK you need to get a manometer on the gas valve and check the inlet gas pressure as well as the burner pressure, this will show up the relative differences between the pressures and could point you in the right direction, there is a filter in the inlet that could be almost blocked, but to clean this means breaking the gas supply and re making the joint and then testing it with bubble test, it may well be better to get a Gas Safe guy to do this for you, if you have a good pilot flame to start then adjusting is not the answer, it is a supply related issue, Rick