so to be clear:
Honeywell =1 red to sunvic 3
honeywell = 3 yellow to sunvic 2
Blue make safe and leave in the wall
sunvic terminal 1 not used is that correct
http://www.sunvic.co.uk/tlx7501rt.html for the sun vic
And
http://www.plumbnation.co.uk/site/honeywell-t6360b-1028-dial-setting-room-thermostat/T6360%20Doc%2018.pdf
For the Honeywell
Hi
I am replacing a 20 year old honeywell room stat with a sunvic TLX7501.
The honywell is wired as follows
Red = 1 this is live 240v
Blue = 2
Yellow = 3
I did a staight swap on the wires ie 1 to 1, 2 to 2, etc but it dosen't work we set the new stat to 35c to call for...