I've got a Powermax 155x about 8 years old. From everything I've read on here I know these things are a pain in the proverbials plus I've struggled to find a professional who's willing to work on it.
I've had a problem with the hot water basically starting out hot and then very quickly going cold.
From reading a few other threads I narrowed this down to the thermostatic blending valve - hot water inlet was hot but output from the valve was stone cold.
I changed the valve Monday night and all seemed well - scorching hot water from all taps.
Come Tuesday morning however hot water was again intermittent - shower only luke warm but also immediately after using the shower I was getting hot water out of the bathroom tap.
This morning shower was fine for me but by the time the missus got in there it was cold again!
I think its the heat exchanger that's now causing the problem as the pipe out of the exchanged into the blending valve is only luke warm at times.
Here's my process of elimination so far (please feel free to correct me as I'm a mere layman)
1 - CH is working fine so there's nothing wrong with the thermal store.
2 - The DHW pump operates when the hot water tap is turned on so I believe that rules out the pump or the flow switch being a problem.
3 - The Blending valve is brand new and I get hot water when the inlet is hot
4 - The pipe from the DHW pump to the bottom of the heat exchanger is red hot so hot water is getting in to the exchanger.
5 - The outlet from the heat exchanger vareies from scorching to stone cold.
I should point out that the flow from the taps is consistently good just not always hot.
So if I'm right and its the heat exchanger is it a case of replacing or simply descaling? either way is this a job I can do myself or am I best finging a pro to help?
Sorry for the long post but this boiler is doing my head in - every year there's one problem or another!!
Hope someone can help
Thanks
I've had a problem with the hot water basically starting out hot and then very quickly going cold.
From reading a few other threads I narrowed this down to the thermostatic blending valve - hot water inlet was hot but output from the valve was stone cold.
I changed the valve Monday night and all seemed well - scorching hot water from all taps.
Come Tuesday morning however hot water was again intermittent - shower only luke warm but also immediately after using the shower I was getting hot water out of the bathroom tap.
This morning shower was fine for me but by the time the missus got in there it was cold again!
I think its the heat exchanger that's now causing the problem as the pipe out of the exchanged into the blending valve is only luke warm at times.
Here's my process of elimination so far (please feel free to correct me as I'm a mere layman)
1 - CH is working fine so there's nothing wrong with the thermal store.
2 - The DHW pump operates when the hot water tap is turned on so I believe that rules out the pump or the flow switch being a problem.
3 - The Blending valve is brand new and I get hot water when the inlet is hot
4 - The pipe from the DHW pump to the bottom of the heat exchanger is red hot so hot water is getting in to the exchanger.
5 - The outlet from the heat exchanger vareies from scorching to stone cold.
I should point out that the flow from the taps is consistently good just not always hot.
So if I'm right and its the heat exchanger is it a case of replacing or simply descaling? either way is this a job I can do myself or am I best finging a pro to help?
Sorry for the long post but this boiler is doing my head in - every year there's one problem or another!!
Hope someone can help
Thanks
