Hi Guys
I just can’t get my head around the wiring to replace my Horstmann 425 Tiara programmer to a new Honeywell ST6400C! Can any expert here help?
The central heating is gravity fed and is controlled by the hot water, hot water is independent but looking at the old wiring the hot water needs to be on with the heating...
Horstmann: Honeywell
I have a junction box where the thermostat for the tank and room are connected.
Picture of Junction Box, left to right:
1. Neutral (yellow)
2. Live (blue)
3. Hot water (red)
4. /
5. /
6. /
7. Heating (yellow)
8. /
9. ? (red)
10. ? (blue
I just can’t get my head around the wiring to replace my Horstmann 425 Tiara programmer to a new Honeywell ST6400C! Can any expert here help?
The central heating is gravity fed and is controlled by the hot water, hot water is independent but looking at the old wiring the hot water needs to be on with the heating...
Horstmann: Honeywell
I have a junction box where the thermostat for the tank and room are connected.
Picture of Junction Box, left to right:
1. Neutral (yellow)
2. Live (blue)
3. Hot water (red)
4. /
5. /
6. /
7. Heating (yellow)
8. /
9. ? (red)
10. ? (blue