problems with old combi

[chuckle bros]

My combi is is only heating tap water but is no longer heating rads, I removed a rad for painting then re fitted it, bleed it, not sure if this is conected to the problem. combi dosen't fire up when I switch it to heating.
make of unit Raven Heat.
Any help would be greatful.

 

[Gasman28]

After draining / refilling the rad, the system pressure would have dropped. Check on the boilers pressure guage for a reading of between 1 and 1.5 bar. Did you drain the complete system?

 

[chuckle bros]

After draining / refilling the rad, the system pressure would have dropped. Check on the boilers pressure guage for a reading of between 1 and 1.5 bar. Did you drain the complete system?

No, gasman, I did'nt drain the system, I just turned off the rad valves and dis-connected the rad then re installed it opened the valves bled the rad then increased the bolier pressure like you said.
I did have probs last year with both the heating and the hot water, the gas fitter at the time replaced the a faulty clock ( the digi display round clock at the front) some times the it would work and some times it wouldn't and the replacement clock fixed that prob, not sure if this has anything to do with the present problem.

 

[gasmick2]

hi most ravenheat boilers especially the 820/20 always revert back to the heating after the water has been switched off, there are 2 micro switches on the back of the diverter valve one is normally open the other normally closed so when the tap is turned on the heating one opens and the water one closes so if the boiler fires up on the water then it has to be with either the micro switch or the clock the other thing with these boilers are that they are factory set on the heating only to 52.000 btus and need to be set the the output req