baxi 80e combi

[jointer]

Hi folks , looking for help ,could only get hot water when heating was on, so bought diaphramgs an replaced both top and front, front one had hole, now I ca n still only get hw with heating on, noticed when heating switched on piston comes out top and operates micro switch, but when asking for hot water only top piston does not come out far enough operate same micro switch, front switch works fine also when I raise contact on top switch dhw comes on, any advice welcome

 

[DeletedUser]

Dodgy diverter

 

[CombustionGuy]

As above

 

[Bapagas]

If top piston does not come out fully then it seems that you may have a blockage in the heat exchanger. You may have to get an engineer to investigate further and rule out other possibilities.

 

[jointer]

Think I'll openen it up again , just check everything is as it should be. Is there any chance an air lock could be the problem,top piston comes out for central heating but not as far out for dhw

 

[picasso]

Good to see bagpuss has managed to answer something reasonably up to date.