Replace 6 wire Switchmaster VA1 with 5 wire Honeywell V4073A

[diywife00]

My husband is about to replace our obsolete Switchmaster (6 wires) with Honeywell (5wire) to our Central Heating System.
The Plumbing is sorted. However, all advice we have seen with regard to the wiring, doesn't adequately explain how to do it.
We believe:-
Switchmaster Blue to Honeywell Blue.
Switchmaster Earth to Honeywell Earth.
Switchmaster White to Honeywell Grey.
Switchmaster Yellow to Honeywell White.
Here is our dilemma...Switchmaster has a Red and Orange wire. Honeywell has an Orange wire. If we remove the Switchmaster Red and Orange, where should the Honeywell Orange go?
HELP anyone?

 

[D_Hailsham]

We believe:-
Switchmaster Blue to Honeywell Blue.
Switchmaster Earth to Honeywell Earth.
Switchmaster White to Honeywell Grey.
Switchmaster Yellow to Honeywell White.

That's correct.

Switchmaster has a Red and Orange wire. Honeywell has an Orange wire. If we remove the Switchmaster Red and Orange, where should the Honeywell Orange go?

Disconnect the Switchmaster Red and Orange wires from the junction box.
Link together the two terminals previously used for Red and Orange.
Connect Honeywell Orange to either of these terminals.

 

[diywife00]

Well that was definitely team work. Wired up. Boiler on. Time will tell. But as nothing has gone bang, I am hopeful that is Job Done.
I appreciate your help with this project. I am new to this site, but will surely need to come back when we get stuck with something else.
Thank you so much!