ALFASOL 3 Solar Heating Controller

[EvSammy]

I came across this controller that is used to heat a tank located in the loft of a house.
The controller seems to be faulty as all 3 temperature sensors are reading -20 deg C.
I cannot find any documentation on this controller and wondered if anyone has come across it.
Do you know where I can get a manual? Search on the internet returns nothing surprisingly.

I have changed one of the temperature sensors but the controller still reads -20 deg C.
Attached is a photo of the unit. Not the best I have taken.

Thanks in advance
Ev

 

[James]

could you have wired the temp sensor the wrong way round?
i would start by attaching the sensor straight to the unit, avoiding any of the existing wiring.
if it still shows -20 then swap the 2 wires round, if it is a thermocouple it will make a difference, if it is a resistive sensor it wont.