Potterton Heatmax Combi water is only lukewarm

20 Sep 2019
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United Kingdom

Recently moved into a new property and getting some hot water issues.

First noticed a problem a couple weeks ago when we moved in, the shower would go hot-cold every minute. I could deal with that for now so put up with it because when it was hot it really was hot. Could do the dishes and stuff because the water went really hot. Not tried the CH once because it's not been cold.

Last week a bloke from United Utilities came and installed a water meter. Could be a coincidence but ever since then, (or maybe a few days after), the water hasn't been going more than a lukewarm at best. The boiler kicks in when you run the tap but it's not heating anywhere near the heat it was a couple weeks ago. Another weird thing is that all the radiators go warm when the tap is turned on even though I've only selected 'Hot water' and not CH & Hot Water with the selector switch.

Ive left all the settings as they have been since we moved in. As mentioned the selector switch is turned to 'Hot water only' but we get heat to the radiators when we run the tap. The CH tempersture control is set to the lowest and the hot water temperature dials are set to maximum. The pressure gauge shows between 1 - 2.5 like the user guide says it should be. The timer is set to off. The digital indicator shows around 62-63 when the hot tap is running and around 33 when nothing is running.

Any ideas why I now can't get hot water? Why is the CH kicking in when all the settings for it are turned off? Could the water meter install have anything to do with it? Any idea why the shower was going hot-cold in the first place?

Any help with these issues would be appreciated.


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