Herz Caledonia HIU & Honeywell T3 Thermostat - Is It Wired Correctly?

[PattyAFC1903]

Hi,

So I’m wondering if anyone can advise. I’ve got an HIU that supplies my new build flat from a district heating system. However it is controlled by a thermostat in the hallway. However the radiators always heat up when I open the TRVs making the scheduling option on the Honeywell pointless.

Does anyone know if this is wired up correctly? I don’t see the corresponding wiring in the HIU to what’s shown in the installation manual in my home pack.

 

[ianmcd]

The grey wire in C sleeved with a blue sheath indicares a neutral, there should not be a neutral in there, is it not tripping the RCD ?

 

[CBW]

The grey wire in C sleeved with a blue sheath indicares a neutral, there should not be a neutral in there, is it not tripping the RCD ?

Tbf mate, it’s confusing, as it appears a neutral should be connected due to the wiring diagram. Maybe it’s because N is the return path/usually completes the circuit? Poorly printed imo.

 

[PattyAFC1903]

Tbf mate, it’s confusing, as it appears a neutral should be connected due to the wiring diagram. Maybe it’s because N is the return path/usually completes the circuit? Poorly printed imo.

Yeah it’s really confusing. I have what I assume is a live, Switch live, neutral and a ground (in a wago connector) in the thermostat. Yet in the terminal box I assume it’s Live, Neutral and ground and no sign of the switched live.

However if we go by the diagram and how the terminals are physically labelled. Then there’s only wires going into switch live, neutral and ground.