Central heating getting hot when i run a bath!

[DannyF]

Hi, I have a potterton puma 80 and when i run a bath the central heating starts getting hot even though the central heating is off a the main switch on the boiler. I have been advised that it may be the diverter valve but when i looked the part up it comes in two parts, the complete valve part and the wax capsule head. Has anybody had any experience with this sort of fault and what did they do to cure it. Any advice apprieciated.

 

[ChrisR]

Here's a representative thread - there are several if you search on +puma +diverter

//www.diynot.com/forums/viewtopic.php?t=50977

 

[RigidRaider]

You sure your house wasn't plumbed by the bloke who built ours? He put the bathroom rad on the same circuit as the HW cylinder coil so that when you draw hot water and the boiler fires, the rad heats up.

Logical, I suppose, in a funny sort of way.....

 

[corgiman]

only if you have potable rads fitted mind

 

[JohnD]

You sure your house wasn't plumbed by the bloke who built ours? He put the bathroom rad on the same circuit as the HW cylinder coil so that when you draw hot water and the boiler fires, the rad heats up.

Logical, I suppose, in a funny sort of way.....

Not unusual. It means the towel rail gets hot for your damp towels. I've done mine like that, connected prior to the 3-port valve so the bathroom gets warm if the heating's on, and if the bath's run (it comes off the circulating water). It is lockshield-balanced back quite tight to stop it stealing all the flow, and has a TRV to avoid summer heating.