Hi there,

Changing my thermostat. The old ones LED display quit and it stopped working.

The old one had the following symbols and wire colours (total of 5 wires coming out of the wall):

Designation Wire colour
W White
O No wire
G Green
R Red
C Black
Y Orange

The new thermostat has W, Y, G, RH, RC, O, B, H1, H2

I've hooked up the W, Y and G wires as per the old one. I tried Red on the RH and Black on the RC with and without a jumper. I got heat once but nothing since. I'm wondering if the red does go on the RH, does it go with or without the jumper to RC and then where does the C (black wire) go?

Many thanks in advance for your help.

Add a jumper from RH to RC hook the red up to either one. The black wire is your common the book should show you the common hook up may be B(check first). Wire the rest the same as the old.