Not really, but it sound like it and my wife is worried that it will explode. So here's the story.
My central heating is powered by an Apollo Fanfare boiler which must be nearly 20 years old. During the summer it worked OK - no noises apart from an occasional slight rattle from the radiators when the pump started up.
Now that the winter (??!) has come and it is on almost continuously, it has started playing up. The symptom is a very loud explosive bang which shakes the whole house. It only happens at odd times - no pattern as far as I can see. Sometimes the system will run for several days without anything happen and then twice in a day. It happened this morning, a very loud bang followed quickly by two softer ones.
I have searched this group and others and the general view is that this is caused by over-heating in the heat exchanger, possibly due to the pump not working. The other possibility is that the boiler is not igniting properly so there is a build up of gas in the boiler which the ignites with a bang.
The pumps seems to be working properly as I can hear it when I hold a screwdriver to the case and my ear. However the pump is wired for overrun via a thermostat in the boiler so I thought this could be faulty. How do I check that the pump is running when it should - apart from standing over it for hours on end!
The gas exploding is another matter which I have no intention of fiddling with! Though the pilot light does seem a bit small when viewed throught the window, Is it possible to turn this up a bit?
Hints and suggestions are definitely welcome, particularly on fault finding, as we don't relish the idea of a cold house on Christmas day!!
Thanks