Puma80e

[jscott]

Ref - 7 year old Puma 80e combi-boiler. Had problem for 6 years, as posted already - when shower operating (victorian style shower hose/tap fitting on bath) the water is intermittent hot and cold throughout shower Only way to get continual hot water is to switch CH on at same time. Is this (as with the other topic answers) a need for a new diverter valve, or is there another answer/issue?

 

[Agile]

What happens if you run a basin tap at half flow when using the shower?

When was the boiler last serviced or repaired by an engineer?

Tony

 

[Softus]

Does it modulate?

 

[sime10]

diverter on the way out

 

[Softus]

Or PCB.

 

[plumbnuts]

Definatly the diverter - they are repairable

 

[jscott]

Thanks everyone for your help - I hopefully know what to ask the engineer now.

I've had the boiler regularly serviced, but no-one has had an answer to the problem. They've said that it is a mystery because the two systems should be different and this shouldn't happen.
Two years ago, I had problem with low pressure, which caused a cut out - solved by engineer by topping up water.
Yesterday, due to a total boiler failure, I had the main modulation control board replaced.
With CH off, I have turned hot tap in basin on half flow, I lost nearly all the water flow in the shower and the temperature of both went luke warm.

Does the above, lead to a different answer?

 

[baxpoti]

Check if the central heating flow pipe warms up when the hot water is on, if it does the wax capsule diverter needs replacing,

 

[ChrisR]

Longshot - are you in a very hard water area?

 

[Softus]

...diverter - they are repairable

They are indeed, but I've had the same symptoms as the OP's from a faulty Puma PP modulation PCB.

It's never definite until the moment it's all working again - then you know.

 

[jscott]

Thanks for your help.
The CH flow pipe doesn't heat up when the hot water is on - so that rules out the wax capsule diverter?
Water around here is hard, but not excessively

 

[Softus]

Does it modulate?

 

[jscott]

Softus - Excuse my lack of knowledge - What am I checking to see if it modulates?

 

[Softus]

Softus - Excuse my lack of knowledge - What am I checking to see if it modulates?

If you open a hot tap while the CH running and the boiler is lit, then the flow switch LED should light up and the burner flames should increase in height.

 

[jscott]

Just tried that - CH already on and flame LED on - when turned hot tap on flame LED went off momentarily and then fired up and went on again. Turned tap off, flame LED went off and has stayed off.