My Potterton Room Thermostat has failed. Model PRT100. The existing wiring on this thermostat is: Blue wire to Terminal 1 (TL); Red to Terminal 2 (H), and Yellow to Terminal 3 (N). Unable to purchase a direct replacement I purchased a Honeywell T6360B Thermostat which only allows the following connections: Live to Terminal 1, and Neutral to Terminal 2 OR 3 depending on switching current. I am left with the RED wire (currently identified as H for HEAT I believe) spare. Honeywell couldnt offer any assistance. Have I purchased the wrong thermostat, or do I no longer require the RED wire?
Red and yellow should be the switching wires with the red being live.
Blue should be for the netral
So 1 and 3 for live and switched live and 2 for the neutral
So from what you are saying, my thermostat has been wired incorrectly by the engineer?
So to clarify:
If you turn the heating on at the programmer can you tell me what colour wire is live?
terminal 1 is live - so is this TL or H symbol? I realise that wiring colours are not standard, so just need to know what connections I require. My old blue cable is connected to TL whatever that is, and Red to H, and Yellow to N.
The live should go to terminal one on the new stat.
Switched live to 3
and neutral to 2
I assume that blue is live as its connected currently to TL, terminal 1. Red is connected to H
Are you able to test them with a meter?
OK, I think I have it, but just wonder why there are 2 neutral connections on this stat. There is one for loads of 10A (Terminal 3) and one for loads under 6A (terminal2). Doesnt that mean I'm using the neutral twice? I somehow think this thermostat is the wrong one.
I have a meter
Ok take the wires out of the stat and tell me which one is live when the heating is on?
OK. will be a couple of minutes
Blue is 240v
The plumber should be shot!
Blue to 1 then
So we know blue is live. Yellow is neutral
Now we just have to find out which one feeds the motorised valve for the heating
If yellow is neutral then that goes in 3
Which leaves the feed for the heating in 3
SORRY NEUTRAL IN 2
So I am left with red which is the switched live?
1 and 3 link for heating on, 2 is the neutral on a Honeywell
So thats all I need to wire the room thermostat
Thats it. I can piece this together now.
Ok, no problem - come back if you need me
Is it working correctly now?