I wonder whether anyone can help me? I have a gas central heating boiler that was installed about 4 years ago. It has recently been cutting out when it should be on (ie thermostat and time set correctly) . I have been advised by a heating engineer that it may be overheating due to having too much air in the system which could be caused by a build up sludge and scale etc.
The system is open-vented and having investigated the expansion/feeder tank in the attic I’ve discovered that there is a lot of sludge in there. The tank has also started overflowing recently through the overflow pipe. I went up to look at what was happening there on one occasion and noticed that there were big bubbles coming up through outlet pipe that feeds the system. When the system is switched off the tank level seems normal and the ball valve operates normally. What seems to be happening when the system gets switched on is that the water enters the tank from the ball valve, but it also comes up from below, raising the water level to the point where it starts overflowing. There is nothing coming out of the vent pipe to affect the water level.
Could this have anything to do with the positioning of the central heating pump? I recently discovered that the company that installed the boiler and pump has a reputation for shoddy work and have recently ceased trading. I’m beginning to worry whether or not they installed it correctly. I’ve noticed on the boiler instructions that the pump which is installed upstairs in the airing cupboard along with the hot water tank should be closer to the feed pipe from the expansion tank than to the vent pipe. However it has actually been connected directly to the vent pipe and is nowhere near the feed pipe from the expansion tank which goes directly down to the boiler without ever passing the pump. Could this have anything to do with why sludge seems to back up into expansion tank via the feed pipe? And could this have anything to do with the build up of sludge in the system, and resulting problems with air in the system and the boiler overheating?
Would be grateful for any advice. Thanks!
The system is open-vented and having investigated the expansion/feeder tank in the attic I’ve discovered that there is a lot of sludge in there. The tank has also started overflowing recently through the overflow pipe. I went up to look at what was happening there on one occasion and noticed that there were big bubbles coming up through outlet pipe that feeds the system. When the system is switched off the tank level seems normal and the ball valve operates normally. What seems to be happening when the system gets switched on is that the water enters the tank from the ball valve, but it also comes up from below, raising the water level to the point where it starts overflowing. There is nothing coming out of the vent pipe to affect the water level.
Could this have anything to do with the positioning of the central heating pump? I recently discovered that the company that installed the boiler and pump has a reputation for shoddy work and have recently ceased trading. I’m beginning to worry whether or not they installed it correctly. I’ve noticed on the boiler instructions that the pump which is installed upstairs in the airing cupboard along with the hot water tank should be closer to the feed pipe from the expansion tank than to the vent pipe. However it has actually been connected directly to the vent pipe and is nowhere near the feed pipe from the expansion tank which goes directly down to the boiler without ever passing the pump. Could this have anything to do with why sludge seems to back up into expansion tank via the feed pipe? And could this have anything to do with the build up of sludge in the system, and resulting problems with air in the system and the boiler overheating?
Would be grateful for any advice. Thanks!