Dear boiler engineers and forum viewers, and ideally an old school former Glow Worm engineer or three,
An odd conundrum.
I have an old Glow Worm Compact 100PP permanent pilot condensing boiler. It was fitted to my house back in 2001, and it was moved to an upstairs cupboard in 2006 when an extension was built. Now, I know that I should really consign it to the scrap heap and have a nice, new, shiny, efficient condensing boiler fitted, but I'm quite attached to the ol' girl' and, over the years, I have bought a lot of spare parts from various on-line places (new old stock) and have a big box full (PCBs - about 10 boards, a new gas valve, two or three fans, lots of thermistors, flow sensor, pressure relief valve, CH pump, spark electrodes, assorted screws, pipes etc etc). The boiler has become a bit of a fixation for me, and keeping it running nicely has been kinda fun (weird I know but I like old stuff). It has actually given good service and been very reliable. I have a good local boiler engineer - a young gas safe fella, who is willing to fit stuff when needed, and sometimes just because Ive found something new to replace an older part. Indeed, he fitted a new heat exchanger 2 years ago, which was major surgery and a bit of a ball ache for him but he did a great job.
To the issue, throughout last winter and the one before, whenever the central heating was on, getting the radiators nice and toasty, and one of the kids decided to have a bath or a shower, turning the hot tap on caused the boiler to shut down - the gas to the burner plate went off and the pilot light went out. I could re-start it after a minute or so, and then it would run OK for a few hours. If the hot tap was run again later though the same thing would happen. It didn't always happen: just enough to be bloody annoying and for there to be some screaming at me to restart it. The missus is not too pleased about the whole saga, but I quite enjoy the game.
Last Christmas my engineer fitted a new fan - in case the exhaust gases weren't being sucked out quickly enough, and a new pump and a flow meter for the central heating, well ... just cos' I had both floating around in the spares box. The various sensors (thermistors) have all be changed a gazillion times, as was the air pressure switch thing, and the PCB is a new old stock and about 2 years into its service.
Now, the game is afoot again for this winter. I wonder whether any engineer or reader has had a similar problem in the past. I appreciate that there are probably few Compact 100PPs still in service, and many engineers saying "what's one of them?" but maybe one of you bright sparks (well bright engineers not to be confused with sparkies) has some ideas about what may be causing it?.
I do not play with the boiler but am reasonably bright and I understand the basic principles of its operation. Clearly, the boiler cut out feature/s are engaging for some reason, probably things are getting too hot or too 'exhausty' (fan - newish, CH flow - pump new, flow meter new) but I cannot figure out why and nor can my engineer dude. If the heating is off, the hot water works fine, and all through the summer we have had lovely, toasty, hot water. Similarly, if only the heating is on, then it runs lovely, and we bask in our budgie smugglers cos its so warm. But both? nope the ol' girl just wont play nicely and she turns herself off.
A gas engineer from the gas supplier Cadent recently tested gas flow at the gas meter from the street and said it was fine. He wondered whether the gas meter in the boiler could be at fault? I have a brand new one in the box, with original seals and the gas jet thingy, all bagged and shiny, so I might get this fitted before the snow and howling winds comes to .... south east Essex. Could this be it? could it be the gas meter in the boiler?
As I understand the ol' girl, she doesn't have a diverter valve, just that when hot water is called for the CH pump shuts off (?) and 'tap' water runs under normal mains water pressure through the heat exchanger (via pipework separate to the CH pipes), gets hot and goes to the taps. So, what could be wrong there to make the boiler shut down when heating is running and hot water duty called for?
I checked the flue when the engineer was fitting the new fan (he took the combustion chamber hood right off and so I could see down the flue. It all seems to be clear and free flowing.
I recon if I can figure this out I can keep the boiler running for a few more years. Its more of a game than anything. I can afford to replace it and I have been thinking about an air source heat pump, and maybe some PV panels and battery storage, but where is the fun in those new fangled contraptions? I may as well put an electric motor in my old MGB Roaster and call myself Sally.
Do any of you massive engineer brains have any ideas about what might be wrong, and/or suggest what I can buy next (if I can find it) to have fitted and solve this long running conundrum?
Any suggestions welcome and gratefully received,
regards and thanks
Stew
An odd conundrum.
I have an old Glow Worm Compact 100PP permanent pilot condensing boiler. It was fitted to my house back in 2001, and it was moved to an upstairs cupboard in 2006 when an extension was built. Now, I know that I should really consign it to the scrap heap and have a nice, new, shiny, efficient condensing boiler fitted, but I'm quite attached to the ol' girl' and, over the years, I have bought a lot of spare parts from various on-line places (new old stock) and have a big box full (PCBs - about 10 boards, a new gas valve, two or three fans, lots of thermistors, flow sensor, pressure relief valve, CH pump, spark electrodes, assorted screws, pipes etc etc). The boiler has become a bit of a fixation for me, and keeping it running nicely has been kinda fun (weird I know but I like old stuff). It has actually given good service and been very reliable. I have a good local boiler engineer - a young gas safe fella, who is willing to fit stuff when needed, and sometimes just because Ive found something new to replace an older part. Indeed, he fitted a new heat exchanger 2 years ago, which was major surgery and a bit of a ball ache for him but he did a great job.
To the issue, throughout last winter and the one before, whenever the central heating was on, getting the radiators nice and toasty, and one of the kids decided to have a bath or a shower, turning the hot tap on caused the boiler to shut down - the gas to the burner plate went off and the pilot light went out. I could re-start it after a minute or so, and then it would run OK for a few hours. If the hot tap was run again later though the same thing would happen. It didn't always happen: just enough to be bloody annoying and for there to be some screaming at me to restart it. The missus is not too pleased about the whole saga, but I quite enjoy the game.
Last Christmas my engineer fitted a new fan - in case the exhaust gases weren't being sucked out quickly enough, and a new pump and a flow meter for the central heating, well ... just cos' I had both floating around in the spares box. The various sensors (thermistors) have all be changed a gazillion times, as was the air pressure switch thing, and the PCB is a new old stock and about 2 years into its service.
Now, the game is afoot again for this winter. I wonder whether any engineer or reader has had a similar problem in the past. I appreciate that there are probably few Compact 100PPs still in service, and many engineers saying "what's one of them?" but maybe one of you bright sparks (well bright engineers not to be confused with sparkies) has some ideas about what may be causing it?.
I do not play with the boiler but am reasonably bright and I understand the basic principles of its operation. Clearly, the boiler cut out feature/s are engaging for some reason, probably things are getting too hot or too 'exhausty' (fan - newish, CH flow - pump new, flow meter new) but I cannot figure out why and nor can my engineer dude. If the heating is off, the hot water works fine, and all through the summer we have had lovely, toasty, hot water. Similarly, if only the heating is on, then it runs lovely, and we bask in our budgie smugglers cos its so warm. But both? nope the ol' girl just wont play nicely and she turns herself off.
A gas engineer from the gas supplier Cadent recently tested gas flow at the gas meter from the street and said it was fine. He wondered whether the gas meter in the boiler could be at fault? I have a brand new one in the box, with original seals and the gas jet thingy, all bagged and shiny, so I might get this fitted before the snow and howling winds comes to .... south east Essex. Could this be it? could it be the gas meter in the boiler?
As I understand the ol' girl, she doesn't have a diverter valve, just that when hot water is called for the CH pump shuts off (?) and 'tap' water runs under normal mains water pressure through the heat exchanger (via pipework separate to the CH pipes), gets hot and goes to the taps. So, what could be wrong there to make the boiler shut down when heating is running and hot water duty called for?
I checked the flue when the engineer was fitting the new fan (he took the combustion chamber hood right off and so I could see down the flue. It all seems to be clear and free flowing.
I recon if I can figure this out I can keep the boiler running for a few more years. Its more of a game than anything. I can afford to replace it and I have been thinking about an air source heat pump, and maybe some PV panels and battery storage, but where is the fun in those new fangled contraptions? I may as well put an electric motor in my old MGB Roaster and call myself Sally.
Do any of you massive engineer brains have any ideas about what might be wrong, and/or suggest what I can buy next (if I can find it) to have fitted and solve this long running conundrum?
Any suggestions welcome and gratefully received,
regards and thanks
Stew
