Replacing Remeha Avanta Plus 39C wireless receiver

[MightySerpent]

Hi all - new member home owner here

My Remeha Rematic RF room stat has a failed mechanical clock. The unit still talks to my Remeha Avanta Plus 39C - manually setting it to thermostat only mode works fine but I'd like to have it on timer again too.

As it is mechanical it has always had a healthy appetite for batteries so I wanted an all electronic replacement.

I got hold of an Optimum OP-Duostat BM from Heating Controls Online as it stated the unit and boiler were compatible and I could see the receiver was the same design as my existing one and so should fit the boiler.

I was hoping for a drop-in fit but of course it doesn't look like it is as the connectors seem to be arranged in a different order.

I have tried pairing the new room stat with the existing receiver but they don't seem interested in one another.

This is a picture of the old and new receivers, the old one is still installed. As you can see they are similar but with different functions for the pins - even I can see the live and neutral are reversed.


This is the plug block the existing receiver is connected to. So you can see which wire goes where.


This is the diagram in the Remeha manual for the above plug block


Finally this is the diagram supplied with the new receiver


So I'd like to know what I have to do to get the new receiver in place with DHW on demand only but with CH controlled by the roomstat and it's clock.

I am not scared of running new wires and I'm aware of the need for electrical safety!

Any advice much appreciated, further pics supplied on request. Ta!

 

[Riley]

Have you taken your boiler cover off

 

[MightySerpent]

For the purposes of taking the pics, yes

 

[Riley]

If you’re not Gas safe then you shouldn’t really be removing the cover. Sorry, you can’t be 100% that any combustion seal is replaced correctly

 

[MightySerpent]

Got it, 100% understand why I should be reminded of that

 

[Riley]

So you’ll need a GSE to fit it

 

[MightySerpent]

So what steps will the appropriate engineer do to solve the problem?

 

[Riley]

Fix The problem with your stat/programmer or wire in the new one

 

[MightySerpent]

Can you provide any detail? I'd welcome a theoretical discussion.

For example, is the theory behind such things not available before the practical application?

 

[Riley]

I’m not sure what you want me to tell you. You need an item wiring to your boiler which is inside the boiler. You need a gas engineer that is competent in wiring to install it then put the boiler back together safely

 

[ShaunCorbs]

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