potterton Puma boiler no hot water

[Veragabb]

Hi, I've got an old Potterton Puma. At the moment the heating is working fine, but the hot water only works when the heating is on.
When the heating is not on, turning on the hot tap will fire up the boiler but the hot water is going to the radiators.
Is this likely to be a problem with my diverter valve ?

 

[ianmcd]

most likely the wax capsule in your diverter valve, changing the wax capsule isnt a big job but replacing the complete diverter valve can be a real ballache at times.

https://www.ebay.co.uk/itm/Potterto...h=item4ad52f9c30:g:P0wAAOxyc2pTcO66:rk:1:pf:0

 

[Veragabb]

Thanks. I have twice ordered a new wax,capsule which turned out not to be the right one, meanwhile my plumber has cleaned and replaced the existing wax capsule but it hasn't solved the problem, so I'm thinking I will need to order an entire diverter valve and hope that it can be fitted.

 

[Dan Robinson]

Diaphram in flow switch or the microswitch is out of position.

 

[Gasguru]

Wax element failed.
Get some WD40 on the grub screws on the front section of the diverter...and just replace the entire front section..
If the entire diverter has to be replaced then a couple of strategic cuts in the framework at the back allows better access to the backnut (bend the metalwork down).
I wouldn't touch the "refurb" ebay diverters....much of the parts described as refurb are just cleaned.
Simple job...