Main combi 24 he problem! No Central heating! Help!

[Stuskill]

Hi everyone!

Wondering if any can give me some advice! I've just moved into a new house and have done some renervating! I've got a main combi 24 he boiler and it ain't playing fair! Basically got the system all fired up again after being off for around 4 months! Filled the central heating system and bleed the rads etc. Pressure holds at 1 bar when cold. When I switch the central heating on the rads don't get hot. The burner fires up for about 10-20secs and turns off. It's all been bleed properly and have even flushed the system just to make there are no blockages etc. When I use the hot water tap it give hot water but I noticed that the burner doesn't stay on for long either. Water goes hot and cold.

One thing I have noticed is that when I turn on the hot water tap the pressure in the central heating system shoots up to 1.5 bar.
I'm not a plumber but done abit of reading and have been told by someone that it's probably the diverted valve.

If anyone has any info or advice would be much appreciated!

Cheers

 

[sjkgasservices]

more than likely diverter valve or slight airlock on boiler

 

[kidgreen61]

It sounds as though the pump is sticking,

you may be able to free it by undoing the large screw on the front of the pump (have a towel handy under it to catch drips), and tuning the impellor with a small flat bladed screwdriver.

 

[Stuskill]

It does sound like the pumps working but it is getting very hot. I did get the boiler serviced a day before and he undone the screw on the pump but don't think he checked wether the pump was sticking or not.

 

[hanns21]

He couldnt have serviced the boiler properly if its not working so i would get him back to correct this. Sounds like he took your money and ran 😱, all the syptoms you say points towards circulation problem,so check the pump and also check the automatic air vent inside boiler is open. Your boiler fires heats up and heat cant go anywhere so turns off