Hello all. This is my first post so please let me know if I have not provided enough information.
My boiler is very old (about 20 years at least) and hasn't been serviced for years. It is an old storage tank type (not a combi). Last winter the central heating pump packed in so I managed to replace it myself with a new one and it worked very well all winter. I didn't use it all summer.
A few weeks ago, two days before my wedding, I had burst radiator pipes under the downstairs floorboards. I drained the system whilst helping the Homeserve engineer. Once we finished we filled the system and bled the radiators. I then turned the heating on to test it and nothing happened. No power light (it is actually the pump speed light) came on. The boiler heated water fine but didn't seem to turn the pump on.
Whilst away my dad came down to have a look. He turned the heating on and the pump worked straight away so I presumed something had corrected itself and all would be fine.
After returning from honeymoon I noticed how loud the boiler was when heating water first thing in the morning (water only not heating). I found out this was "kettling" so I drained the system and added some Sentinel X200. I then bled all the radiators and the central heating pump. In order to pump the additive around the system I put the heating on for a few hours over a couple of nights.
I turned it on again on Sunday to give it another pump around. It worked fine but when I went to bed to turn it off I noticed the light was off on the pump and it wasn't working despite being set to constant. The boiler was working fine and still heating the water.
The next morning I turned the heating on and the pump worked. I got back from work and turned it on again and it worked. However, after a couple of hours I noticed the pump had turned off again despite it should have been on. This pattern repeats itself. Once turned off it will not turn back on again until the next morning.
Any advice would be welcome