Hive install complicated by wired room stat

[wrathalanche]

Hi all,

I moved recently and took my hive system with me, planning to replace the Drayton LP711 timeswitch already in the house. My understanding was this would be a 2 min swap job. I didn't foresee running into the Danfoss room stat at the other side of the house, which has me a bit weary of proceeding.

The wiring for each is buried in the walls and for the life of me I can't find where it enters the boiler (Vokera Compact) or a wiring centre. It's early days though. Only been in the house 48 hours.

The Drayton is wired with two flexes: one to N, L, and a link been L and Common. The second fleX goes to N and NO.

The stat also receives two flexes at the other side of the house. One to N and L, the other to terminals 2 and 3.

In an experiment, I removed all the wiring from the stat back plate and swapped the hive into the Drayton plate without changing anything. As expected, the hive lit up calling on heating, but the boiler didn't respond.

From similar topics on the forum, I'm getting the idea that - short of removing the stat wiring completely from the source - I, as a minimum, could insulate the N & L flex, and join the signal wires (pins 2 &3).

Can anyone confirm if this would effectively remove the stat from the equation, and that the hive can take the place of the Drayton without touching the wiring?

Pics attached: Drayton timeswitch wiring, then stat wiring.

 

[ianmcd]

put the hive on and then refit the origional thermostat and turn it up to full, if everything starts working as it should you need to join the switch wires in the existing roomstat

 

[ollski]

Not sure I follow what you've done but the hive receiver fits straight onto the LP711 backplate I think with the same connections and you remove the thermostat wires from the boiler pcb and fit a link onto the board connections for the stat.

 

[wrathalanche]

Thanks for the help so far. I've had a million other jobs to do since moving in, so it's taken a while for me to get back around to sorting the hive out.

I tried what you suggested, ianmcd, with regards to turning the stat up to full with hive fitted, and the boiler started up. So I removed the power and joined the signal wires behind the stat.

As I understand it, this would have the same effect as what ollski had suggested.

This lead to the boiler firing up and constantly heating. I couldn't seem to turn the heating off with either the hive thermostat or the app, so I've returned it to how I found it, to try another day.

Part of me wonders if I should have just kept it set up a bit longer and tried resetting the boiler at its controls to try to get it cycling correctly again.