Honeywell T40 to moes bht-002 installation help

Sponsored Links
I am back
Unfortunately my experiment didn’t work.
I have buzzed the cables from the junction box with the one in the thermostat and none of them worked so I couldn’t bring the neutral to the thermostat.
Now I’m stuck, I have found a power socket close to the stat, I was wondering if I can run a live and neutral from the socket to power up the thermostat and use the exiting live and the switch live for the opening and closing of the heating and don’t use the blue cable.
Is it risky to do it?
No it must come from the same supply as the boiler
  • Thanks
Reactions: CBW
You may have to install, it near that wiring center, as your original wiring didn’t work out having the 20 v between live and neutral.
Sponsored Links
When you carry out the voltage tests, you are aware that there won't be a live to the thermostat unless the central heating programmer is set so that the heating is 'on'

If you remove the L & N wires from thermostat terminals 1 and 2 and then test them with the heating set to be on at the programmer, what do you get?
Is this the wiring centre?
Because if it is I don’t have cable from here going to the Thermostat
I know Stem.
I have test voltage between line and earth and I have 240v
So just to be clear with the wires removed from the thermostat and the programmer set to heating 'on' you get

20V between red and blue

220V between red and yellow
Yes, the programmer is always on.
Also I have tried to check for continuity between the junction box next to the programmer and the thermostat and I don’t have anything so I am wondering where are the cables coming from.
The thermostat cable could go to the wiring centre / junction box, programmer or the motorised valve. It all depends upon the preference of the original installer. As a clue, the yellow wire should eventually be connected to the live wire at the heating motorised valve, so that when the thermostat switches 'on' the valve opens. But where it is actually connected is the question, you may just have to physically trace it....
@Chris_W , Chris these thermostats are cheap chinese Tat, the are a one part unit , they dont have a receiver

I know mate, but he’d need a permanent live and permanent neutral, so would think it’s best installed there?

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links