Blazing Hot Water

[JackRegan]

Hi

Setup is. : Vailant ecotect plus 630 / Tempest water tank / codice 542794 thermostat

The hot water has gone from hot to blazing. Ie too hot even for rubber washing up gloves.

From what I can determine the water temp is set by the thermostat which is attached to the water tank - codice, is that correct?. The Boiler has no hot water temp setting, only heating.

It was set to 45 - which it has been for a few years. I turned it down to the min, 25 this morning and this evening the hot water is still too hot. The timer is set to about an hour in the am and an hour in the pm at the moment.

This evening I turned the system off, pressed the thermostat reset button for 10s. Too early to tell if its made any difference.

Is the water temp linked to that thermostat?

Paul

 

[terryplumb]

Is your boiler at work during periods that the timer is in an OFF period ( hot water off) ?

 

[CBW]

Has someone inadvertently turned the immersion heater on?

 

[JackRegan]

Is your boiler at work during periods that the timer is in an OFF period ( hot water off) ?

I just looked and yes. The timer is off but the boiler is still running.

 

[terryplumb]

Sounds like a zone valve may be stuck, it's microswitch permanently closed circuit.

 

[JackRegan]

Now you have pointed that out I vaguely recall the engineer mentioning something about the boiler had been always running and he tweaked a setting when I took out insurance. 12-18M ago.

Thanks for your help. I’ll call them out.

 

[ianmcd]

As @CBW correctly says more likely that it has an immersion heater and that has been turned on and is faulty, if your boiler is set at 45 degrees the the HW can not be higher than that

 

[JackRegan]

As @CBW correctly says more likely that it has an immersion heater and that has been turned on and is faulty, if your boiler is set at 45 degrees the the HW can not be higher than that

There is an immersion but it’s certainly off at the wall switch.

 

[JackRegan]

Fixed (temporarily). This switch wasn’t functioning properly. Had no resistance.

Switched the system off, gentle tap with a screwdriver, power on and it’s working.

I guess it needs replacing at some point.

Thanks for the help and advice.

 

[CBW]

Fixed (temporarily). This switch wasn’t functioning properly. Had no resistance.

Switched the system off, gentle tap with a screwdriver, power on and it’s working.

I guess it needs replacing at some point.

Thanks for the help and advice.

That's a 2 port motorised valve and the actuator (powerhead) contains the switch so probably just a new head required