Replacing underfloor heating thermostat

[Jamiedee90]

Hi all,

Trying to replace my dead under floor heating thermostat and I'm struggling as the letters on the back differ. I understand where the live, neutral and two sensor wires go (assuming it doesn't matter which way around the sensor wires go in?) but I have no idea where I put the wire that previously was in L1, can anybody help. Do I need a different thermostat? Thanks I'm advanced

Best
Jamie

 

[Murdochcat]

Not being picky but you seem to be missing a connection to the existing unit

 

[CBW]

As above, was there a wire that went from L to N1?

 

[Jamiedee90]

No wire from L to N. I've attached the connection to the control panel below

 

[RandomGrinch]

It's a switched live output on L1 on the existing stat - no need for any other wires; the neutral (to the load) could be connected anywhere (hopefully from the same circuit).

The new stat would simply require a short link wire between L (2) and COM (5).
The black wire would then connect to NO (3).

However, the bigger concern is the maximum output current; the existing stat is rated at 16A, when the new stat is 3A.
Does this stat directly power an underfloor heating mat, or an actuator?

 

[Jamiedee90]

It powers the control panel not the actuator. I bought the new one before I even realised they were different

 

[RandomGrinch]

It powers the control panel not the actuator. I bought the new one before I even realised they were different

Sorry, I didn't see post #4, as I was writing at the same time.
Looking at your photo, the thermostat is controlling the actuator of a wet UFH system, rather than powering an electric heating mat.
A thermostat with a 3A switching rating *should* be sufficient (depending on your actual system specs).

In which case, in addition to the L, N and NTC connections...

The new stat would simply require a short link wire between L (2) and COM (5).
The black wire would then connect to NO (3).

...the wiring in the Wago (type) connector looks interesting though - there shouldn't be two wires in the same port, and where does the extra black wire go to?
Also, is the stat mounted into a metal back box?