Need help to diagnose a (lack of) hot water problem

[grahamm]

I'm looking for some tips on diagnosing my hot water problem. My system is as follows:

Potterton Prima F50 bolier (I believe)
" " EP2002 timer module
" " PRT2 room thermostat
" " PTT2 hot water tank thermostat
Grundfos pump
Sunvic unishare valve

First observations are that the timer module is alive because all the lights and display appear to be doing the right thing. Same is true of the room thermostat. If I advance the CH the boiler lights up, the pump starts and the rads warm up.

However the hot water tank thermostat has no lights even when the HW is advanced. The live of the base plate appears to be live. So I believe the fault is the PTT2 tank thermostat. Failing that something has gone wrong with the timer module. Also would a failure of the tank sensor be an issue?

Is there any way I can be sure before replacing parts one after the other?

Thanks,
Graham

 

[kevplumb]

turn the h/w stat up and see if the system starts up on h/w only

 

[grahamm]

Nothing unfortunately.

Normally when the temp is reached on the thermostat unit there is a red light, and green when temperature is low. I'm getting no lights at all, which is why I think the thermostat unit is duff.

 

[grahamm]

Just for closure of this thread. I purchased a replacement hot water tank thermostat and this resolved the problem.