Help needed! Drayton Combistat to Honeywell DT90E wiring

14 Sep 2011
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United Kingdom
Hello please can any one help?

I have a Drayton RTS8? Combi-stat , the current wiring is:

red to 'L' connection
Blue(with small little red sleeve at the end) to 3 connection

The earth is also connected.

I want to swap it to a digital Honeywell DT90E
The DT90E has A B C connectors

Could some one let me know if I am correct in thinking that the red one in L at the moment on the combistat should go to A ? and the blue should go to B or should the earth lead be used - what happens to it?

Here is the Drayton wiring...

Thank you
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