Vaillant EcoTec Plus 832 - Water too hot!

[HotHands]

Hello everyone!

I have a Vaillant EcoTec Plus 832, about 5 years old now. Never had any issues with it until now...

A few days ago I noticed that the water from the hot taps was EXTRMELY hot. After a bit of head scratching, I thought someone may have fiddled with the temperatures on the boiler. After a quick look, central heating was set to 55*C and the DHW was also set to 55*C. However, upon further investigation, I can see that when a hot tap is open the boiler is heating the water to 75*C! It appears to completely ignore the temperature set for DHW and is heating it to the maximum temperature.

There are no error codes, and no other signs of malfunction. Heating still working perfectly, it's just the the hot. As you can imagine, this isn't only very wasteful but could be quite dangerous too.

Can anyone suggest what could be wrong? Or how I could go about diagnosing it?

From my point of view, the boiler knows what temperatures are set, and is also measuring the DHW correctly (ie, it's reading 75*C, the actual temperature rather than the requested).

Thanks everyone!

 

[CBW]

That’s not the temperature that will be arriving at the taps, that’s the flow temperature at the boiler. I’m guessing you have the combi version? Normally they heat the incoming cold to a temperature rise above depending on litres per minute.