Wiring open therm stat

[Matt0029]

When wiring in an open therm stat. Swapping a boiler and swapping the wired stat on the wall, Honeywell one. For an open therm one. I know you take two wires I believe from the supply to the boiler to the open therm connections in the boiler. Ideal instinct. Am I right in saying open therm is low voltage? I need to get the instructions for the stat and read up. Thanks for any insight.

 

[ShaunCorbs]

Yes around 5v I think

 

[Matt0029]

Thanks any idea what gets wired across to the boiler open therm connections, is it switch live?

 

[ShaunCorbs]

No think of it like data connections normally a 2 core

 

[IND_Nick]

There is normally a dedicated Bus or 'open therm' terminal block for the two wires. Some manufacturers use different terminology and they aren't all compatible.
I may be wrong but I don't think the Ideal Instinct has an eBus system, I'm happy to be corrected on that though.

 

[Matt0029]

It does have a separate terminal on the right of the boiler for open therm. Just 2 connections

 

[IND_Nick]

It does have a separate terminal on the right of the boiler for open therm. Just 2 connections

I thought it was odd as most have this type of system available, I only flicked through the manual on the wiring page, but it may have been updated from the version I have.

 

[Deleted member 120897]

I don’t believe it matters on OT, as it’s not polarity sensitive, so no switched live. You’ll need L-N-E for the power supply if wireless, and 2 wires for OT. Otherwise it’s just the 2 wires.

 

[Matt0029]

It does have a separate terminal on the right of the boiler for open therm. Just 2 connections

Was thinking of using the old stats wires from the wall stat for open therm. The boiler is wired in 5 core. And swapping the hard wired stat for the open therm stat.

 

[ShaunCorbs]

Can’t run high and low voltage together in the same cable

 

[Matt0029]

The live neutral and earth coming to the boiler would be in the same cable as the stat wires. So I couldnt use this 2 wires to take a feed to the open therm connections? Putting wagos on the 2 stat wires and running heat resistant 2 core to the open therm?

 

[Matt0029]

If not acceptable with the current wiring set up I'll look at just putting a hard wired stat on. Boiler plus compliant

 

[Deleted member 120897]

Can’t run high and low voltage together in the same cable

Is this to do with ghost voltages, inductance or something? Is it a BS?

 

[ShaunCorbs]

Is this to do with ghost voltages, inductance or something? Is it a BS?

Correct your spot on

 

[Matt0029]

Can you explain more please. Thanks