Randall 4033 into a Randall 3022

4 Oct 2006
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United Kingdom
Having just moved into my new house it appears that the parting shot of the previous occupiers was to leave us a knackered central heating timer. Fortunately (?) it was a Randall type 3022 and I happen to have a spare Danfoss 4033. Although they both have similar backing plates that will allow the 4033 to plug into the 3022, even I know that it would be too simple to do a straight swop because the 3022 provides only heating or hot water priority whereas the 4033 gives a bit of greater control by separating the hot water and heating. The question is - is it possible to rewire the backplate of the 3022 to receive the 4033 and get some timer control? If so how? there are 7 terminals + earth on the back plate and both timer units.

The easy answer is to replace with an electronic unit - and this is planned. What I am seeking to achieve is a short term fix as winter draws in!!

Thanks for any help
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What's your motorised valve?
Is it a V4044C? If so it's a true diverter valve and not a mid position valve so it won't do CH + HW together.

If you change the valve to a V4073 Mid position valve (for Y plan) you'll need to get extra wire(s) from the valve back to the wiring centre. Is that OK?

You can just change the actuator to change the valve function, the brass body's the same.

Otherwise you'll have to stick to W plan, or a modification of it.

It's not quite a straightforward changeover whichever programmer you use, even if you stick with the V4044, but once you've rewired for a normal programmer, or 4073 valve and programmer, changing to another programmer is easy.
Your 4033 counts as a "normal programmer" :D

Y plan is here,
http://content.honeywell.com/uk/homes/Catalogue/Sundial Plans/3.4 Y Plan.pdf
W here
http://content.honeywell.com/uk/homes/Catalogue/Sundial Plans/3.3 W Plan.pdf
read the "Operation" description H give to see if you can live with W plan!

The snag is that the "time controller" which H show is NOT what a 3022 does. So you have to work out from scratch which wires are which going into the 3022, with or without help from the 3022 wiring diagram

I have the wiring for the 3022, would need to scan it - it isn't on the Danfoss site.

What are the boiler, room thermostat and cylinder stat?

I thought that the 3022 were extinct - if you do have one it could be the simplest and easiest answer in the short term.

Chris R

Thanks for your illuminating reply and the diagrams. I can confirm that I am stuck with the old 4404 so would need to change/modify it to get the separate HW CW Function.

I would appreciate the wiring diagram for the 3022 and 4033 if you have them as they would be a great help.

The boiler is a Glowworm (haven't found a model code yet)
Room stat and Cylinder Stat are both Satchwell

Thanks for your help

Gary G
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:LOL: Renaissance, i have a spare 3022 that works and could do with a 4033 for a relative ,i,d be happy to do a swap if your not sorted, regards.

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