DIY Doctor UK DIY Forums

Hi,
I've got a combi powermax 155x boiler.
It is about 5 years old and I have never really had a good supply of hot water especially when the heating is on.
We just turned the heating off waited for a while before a shower.
This has now got to a stage where the water will not last for more than 1 minute without the heating on.
There seems to be good flow of water from the tank through the pump and heat exchanger and back to the tank. The pipework on b :cry: oth sides of the H/E are roasting hot.
However the cold water feed into the H/E will get hot intially and the external surface of the H/E is too hot to keep your hand on it. But the cold water out which goes to a blending valve with the cold water inlet pipe loses temperature quickly if say the bath/shower is turned on. If the sink taps are turned on the water will last longer. Which makes sense.
So question is has anyone had experiences like this and is it likely to be the blending valve or heat exchanger or something completly different?

Thanks,

Graeme.

I've got a combi powermax 155x boiler. Combi ????

There seems to be good flow of water from the tank through the pump and heat exchanger and back to the tank. ???


Combi with tank

Range Powermax 155X. I meant a combination of heating/water if that is the reasons for the ?
I was also referring to the supply of water through the plate heat exchanger via the pump.
Not sure if I have replied correctly to your post.
Please let me know if I have misunderstood.

Thanks,

Graeme.

Have you checked to see if the pump was working properly? I would want to ensure water IS circulatiing before examining the blending valve. The heat exchanger would be the last suspect.