Replacement for Potterton PTT2 Cylinder Thermostat

[jamezm]

Hi guys!

My cylinder thermostat has broken (well, it's literally been smashed while I was moving some things around), so I can no longer adjust the HWC temperature.

I was hoping to do a nice and easy quick swap, but cannot find this part anywhere! Can anybody recommend an alternative HWC thermostat that would be a reasonably easy swap for this 5-wire unit - the Potterton PTT2?

Thanks in advance.

James

 

[stem]

The PTT2 is slightly unusual in that the control dial and wiring terminals are mounted remotely from the cylinder and it has a separate remote temperature sensor.

The easiest way to proceed is to replace it with like for like, if you do manage to find one.

If you want to use an alternative replacement, such as strap on cylinder thermostat, (eg Honeywell L641A, or Drayton HTS3) you can do, but you would need to replace the present PTT2 with a terminal box having a flex outlet and then run a heat resistant cable to the new thermostat. Most cylinder thermostats including the examples above, would only need to use the following wires. The instructions will confirm if this is the case or not.

Switched live from programmer - presently connected to T(4)
Call for heat - presently connected to H(1)
Satisfied - presently connected to C(2)
Plus earth if required by the new stat

The permanent 230 VAC supply to the PTT2 (N & L to terminals 3 & 5) would not be required as this is used to power the device and provide the boost function when the programmer is off. So these wires should simply be terminated and made safe.

 

[jamezm]

Thanks for your help.

No sign of any PTT2 thermostats anywhere but will keep my eye out.

 

[KLS611]

Just sourcing one right now for a customer - 'More than 10' would appear to be currently available on eBay, described as being New - eBay item number:151551619082

Hope you get sorted out
Regards