Potterton EP2002, PR2 to Tado & Extension kit

[jamezm]

Hi guys.

Getting really frustrated by this Tado install.

I have/had:
Glowworm Ultimate (FF) boiler
Potterton EP2002 programmer (adjacent to boiler)
Potterton PR2 room thermostat (wired from lounge)
Potterton cylinder stat (wired from upstairs airing cupboard)
Gravity fed water

I followed Tado’s instructions initially to just install the new room thermostat (and Tado bridge) in place of the PR2. This worked fine straight away allowing me to control central heating.

I subsequently bought the Tado extension kit in order to control the hot water as well. This is supposed to replace the EP2002 programmer. I followed Tado’s instructions to connect the existing wiring to the new Tado extension kit (all three live cables to the single live terminal, all three neutral cables to the single neutral terminal, all three earth cables to the single earth terminal, cables ‘3’ and ‘4’ to the corresponding terminals 3 and 4, and discard the linking cable between the live terminal and terminal 5). No changes with the cylinder stat.

Tado’s hot water controls work fine but Tado’s central heating controls no longer work. Tado thinks everything is fine but in fact the boiler is not firing up for CH, only for HW. Radiators are not warming up.

I’ve asked Tado for guidance but I don’t seem to be getting anywhere! Can anyone else help?

I’ve attached a pic of the ORIGINAL thermostat wiring and the ORIGINAL programmer wiring but it’s difficult to make a lot of sense of this. Unfortunately, Tado doesn’t allow me to receive the bespoke install instructions again so it’s hard to double-check what I’ve done or retrace my steps.

Regards,
James

 

[jamezm]

Bump

 

[stem]

You are correct the wiring for the tado extension box is:

And the EP

So terminals N,L,1,2,3 & 4 correspond exactly, so the wires from the EP are exchanged exactly. You loose the link between L and 5 at the EP, because the tado has this connection internally. And doesn't have a terminal 5

Things to check.

1. The jumper setting on the tado extension box is in position 2 as shown above

2. Originally, I understand that the new tado thermostat was wired in. It is now a "wireless sensor and remote control" as per the second bullet point below:

This means that the switching wires in the thermostat terminals 'com' and 'no' are not required. Unfortunately I have only a wired a standalone tado thermostat, and one that had a bridge from the start. so, I have never converted a tado wired thermostat to one with a bridge, so I don't know if it would work with the wiring still in place. However, if we were to assume that it was installed with the bridge from day one and the thermostat switching wires not present, you could achieve this by joining the thermostat switching wires in 'com' and 'no' together. Putting them both in the 'com' terminal would do this.

You may also have to reinstall the tado from scratch, I'm not brilliant with software, but it maybe that the thermostat is isn't communicating with the bridge as it was originally set up in wired mode.

 

[jamezm]

Thanks Stem. It was reassuring to know I'd at least got the programmer cabling right (hard to get wrong if the terminals correspond!).

I've finally managed to get it to work (fingers crossed) by going into the pro Installer Menu on the smart thermostat (for future readers: hold down the button for three seconds to bring up the pairing status icon and then hold it down for a further three seconds to bring up the toolkit icon). There is then an option to adjust the equipment configuration to "T5" (which seems to be for my setup - consisting of a room thermostat, an extension kit, and hot water controls). It seems the consumer setup process doesn't correctly set up the configuration when adding an extension kit to an existing Tado setup. A fresh install would probably have achieved the same thing but I'd been waiting a couple of days for the factory reset to be applied by Tado as you can't do this yourself except in the pro Installer Menu.