Thermostat replacement

[newtothis123]

Thanks in advance for your help.

I have an old mechanical thermostat that I'd like to replace with a programmable CM907.

My current thermostat has three wires. These are terminals 1) Red wire. 3) Yellow wire and 4) Blue wire. I attach the accompanying diagram.

The CM907 only requires two wires. I understand the neutral wire should be capped off. Can you confirm, from the wiring diagram, which wire is neutral, and should be capped off, and which I should connect to my CM907, and where?

CM907 diagram:

Thanks.

 

[bellairaphon]

Yes Red into A Yellow to B. block connect the neutral.

Nath