I have a standard 'y' plan central heating system with a Honeywell V4073A1039 3-port diverter valve.

The central heating was obviously installed by-the-book because the wiring almost exactly matches that listed on the installation manual for the valve.

enter image description here

I want to replace the motor head on the valve with a new one. However, the new one has SIX wires (the same five wires shown on the circuit diagram, plus a brown one).

With reference to the circuit diagram shown, where should the brown wire go?

The instructions for the complete valve includes the wiring diagram for the full CH system (shown here) but the instructions for the motor head replacement only includes an internal circuit, it doesn't mention how to wire it to everything else. The instructions for the replacement part indicates that the brown wire is the live wire for the valve motor, so leaving it unconnected is probably not an option. The vendors were willing but couldn't help, the manufacture Resideo don't respond.

Solution. Ok. Pretty simple solution really. I bought and paid for a 40003916-003 valve head, and had delivered a 40003916-001. This link makes it clear they are not compatible. Bummer.

  • You've been around long enough to know that answers go down there vvv, not here in your question.
    – FreeMan
    Commented Oct 26, 2023 at 13:46
  • Between the original question, your comment and edit you've made reference to 3 or 4 different valves. When I answered the question there were two different three-port valves with different wiring requirements and the "wrong" one you claimed to have, COULD be wired to your system with special instructions. Your comment and answer refers to a two-port valve. As long as you are less confused than I am, I hope you'll work this out!
    – jay613
    Commented Oct 27, 2023 at 1:29
  • @jay613 - I now have a working CH system. thanks for your help. I too was confused, there are a bewildering variety of valve types, part numbers and spares, some of which are or aren't compatible with each other. Even the instructions use the words valve/powerhead/motor/controller interchangeably. All sorted now Commented Oct 27, 2023 at 7:31

1 Answer 1


Your shopping link says "5 wire installation", and the documentation shows five wires and instructs you to phone Resideo if you need six wires for an older installation.

This document from Resideo refers to an "older" six-wire version of your valve and tells you how to wire it. You can follow these instructions. You could also keep trying to contact Resideo. It can take time (a week or more) to get a response but the will help you.

You could also ask your supplier to change the valve they sent you to the correct more recent one. That is what I would do, worrying about warranty and support issues with an older model.

  • Thanks for taking the time to respond. I've found the solution, I've bought and paid for the correct valve (part no. 40003915-003) I've been sent the wrong item (part no. 40003915-001) Commented Oct 26, 2023 at 12:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.