Vaillant VUW242E Water too hot

[caffreys]

My old vaillant vuw242e DHW is too hot even when turned down would this be a thermistor problem ?

 

[Agile]

Could be but its rare on that model.

Could be several different things and some diagnostics would be needed.

For a start set the DHW flow rate to 9 li/min and measure the water inlet/outlet temperatures!

Tony

 

[caffreys]

Thanks Tony,
Looking at the boiler diagram there's not a lot else it can be, unless it's the main control board or the heat exchanger (but we don't have a lot of build up here so can't imagine it's that) Hasn't been a gradual increase just happened suddenly - I'll get some temps later.
The manual doesn't appear to have any fault finding instructions for this fault and there's no warning lights.

 

[Agile]

It can be all sorts of things!

Several different gas faults for a start!

Thats why a good boiler engineer is often needed!

Tony

 

[caffreys]

okay it'll have to wait tho I can live with it for now.
Incidently the temp gauge on the front of the boiler is reading 60c, only dropping to 50c at position 2 on the hot water control.

 

[Agile]

The gauge reads the boiler's internal temperature and NOT the DHW temperature!