Hot water ok but no heat to rads

[Jollygreengiant]

My girlfriends CH was playing up and now there is no heat to the rads at all.
It's an old vaillant combi. not sure how old and I can't see a model number. it's very basic with no fancy electronics though so I said I'd take a look

Hot water is fine, the pump is spinning and is very warm so from the little I know I'm assuming there is a problem with the diverter valve /motor?

How easy are these to replace? Do I need to get a specific motor or are they pretty universal?

Cheers all
Carl

 

[corgiman]

no its a bugger on them get some who knows whats what with a combi for christs sake

the servo has probably gone and if you dont knwo what you are about you have two hopes in sorting it and one of them is relatied to bob

 

[Jollygreengiant]

Tried to get on here last night but couldn't - turns out it's a 242 and I had exactly the same problem as several other people seem to have had with the diverter valve microswitch just not quite depressing enough to make the CH fire up. The slightest touch was enought to make it trip so I just adjusted the screw by 1/4 turn and Bob's your uncle.

The water seems very black too so it may well be down to sludge in the valve as some have said. We need to change a radiator so when that comes off I'll take the opportunity to flush it all through.

 

[2face]

fernox f1 cleanser ... and add inhibitor after .. fernox f3

 

[Jollygreengiant]

Already have some in the van...