Yet another Potterton Prt2 Thermostat Replacement Thread

[Thomas Kranenburg]

So I've got a new Z-Wave smart thermostat. Does my wiring look right from my old Potterton Prt2 Thermostat?

Old:

New:

Yet to hook it up. Does this look right?

 

[RandomGrinch]

Does this look right?

I'm afraid, not quite.
Your new stat is designed predominantly for electric underfloor heating - it provides double pole switching, i.e. a live and neutral in, and a switched live and neutral out.
To replace the existing Potterton...
The Red wire in terminal 2 (COM) would connect to 'L' on the new stat.
The Blue wire in terminal 5 (N), would connect to 'N'.
The Yellow wire in terminal 3 (H), would connect to 'Heating L'.
No extra links are necessary.
The Green and Yellow earth wire would be left safely isolated in a separate terminal block.

 

[Thomas Kranenburg]

Thanks for your help. Does this look ok?

So is there no internal heat sensor built into it? I will have to get a sensor connected to top right to get a temperature sensor to it?

 

[RandomGrinch]

Does this look ok?

Yes, that looks ok.

So is there no internal heat sensor built into it?

Double check the model number of the stat you have - the picture you show is of the Z-TRM3.
This does have a built in sensor...

Other versions do not.

 

[Thomas Kranenburg]

You're a great help RandomGrinch. Thanks a huge amount. It was really hard to find a decent looking Z-wave thermostat that would work in the UK. I've basically got to use this one or go with something ugly in my front room.

 

[Thomas Kranenburg]

Right right. I see what you mean about double pole switching as well. Did some reading and I feel I understand your solution now as well. Which is a lot better than just doing what you're told isn't it.

Just dropping the full name of this thermostats for some poor soul searching through google:

Heatit Z-TRM3 White RAL 9003 Z-Wave Plus thermostat 16A

 

[Thomas Kranenburg]

One final thing I'd like to ask, my existing thermostat controls a gas boiler. It's just a simple on/off. It's a dumb thermostat with no other features.

The website I bought this from did not say it was for electrical heating only. Or that it was for flooring. This was specified for other items but not for this one. I should I have checked the manual first. Silly mistake.

Basically can I still safely install this to fire the gas boiler?

 

[RandomGrinch]

Basically can I still safely install this to fire the gas boiler?

Yes you can, if the Potterton worked well in it's mounted position, I don't see why the in-built sensor of the Z-TRM3 should be any different.
Try it and see!

 

[Thomas Kranenburg]

Second update.

Contacted the manufacturer and an electrician friend. They both confirmed. Will install and report back.

 

[Thomas Kranenburg]

Installed and works beautifully. Really pleased with the product. Takes a while to calibrate but very effective.

Nice easy switch over. Hardest part was cutting through the drywall really. Thanks for your help @RandomGrinch