Replacing EP2001 programmer with Siemens RWB29

[SteveDungey]

Our 20 year programmer has finally given up the ghost, (display missing and CH light on with nothing else functional).

I want to replace this with the Siemens RWB29 but assume I will have to fit the new backplate.

The photo is the current wiring, and the schematic is the wiring for the RWB29.

System is fully pumped with a single flow control valve.

Anyone able to help with how to wire up the new backplate please?

 

[SteveDungey]

Anybody any idea what colour wires in my existing backplate do what function please, (HW Off/CH Off/HW On/CH On)?

I assume that all I need do is to wire up the new backplate as per existing without the L to 5 link?

 

[45yearsagasman]

That would appear to be correct, but I can't remember the Pottertons internal wiring. You should check that first. Why not use a new Potterton programmer and forget about rewire? Just a thought.

 

[Echo the husky]

It will be exactly the same number for number. There will be no number 5 so the link between L and 5 goes in the bin as this connection is made internally in your new programmer.

 

[Whitespirit66]

The new Potterton EP2 will fit straight on without needing to change the back plate - unless the locking tab at the bottom of plate has snapped off, which is often the case. Otherwise follow the instructions above for wiring new Siemens, which is a fair bit cheaper than the EP2.

 

[SteveDungey]

It will be exactly the same number for number. There will be no number 5 so the link between L and 5 goes in the bin as this connection is made internally in your new programmer.

Excellent thanks for the information.

 

[SteveDungey]

That would appear to be correct, but I can't remember the Pottertons internal wiring. You should check that first. Why not use a new Potterton programmer and forget about rewire? Just a thought.

Unfortunately I can't find any information about the EP2001

 

[Steelmasons]

So a tight bastad decided to cut the flex off a 3 port valve rather than use 5 core and earth?
Using earth core as a permanent live...ok it's sleeved but jeez...

Possibly the OP having a laugh??

 

[Whitespirit66]

So a tight bastad decided to cut the flex off a 3 port valve rather than use 5 core and earth?
Using earth core as a permanent live...ok it's sleeved but jeez...

Possibly the OP having a laugh??

Yes, I couldn't work that one out for a minute or two. Couldn't see how having just mid-pos wired to programmer could make the system work. Then I realised it had poss been lashed up with some offcut.

 

[Echo the husky]

Who says the wiring centre isn't right below the programmer? You won't see me using a g/y for anything except earth, sleeved or otherwise. I stock multicore flex on the van.

 

[Steelmasons]

Who says the wiring centre isn't right below the programmer? You won't see me using a g/y for anything except earth, sleeved or otherwise. I stock multicore flex on the van.

No one..but that is not the point and a moot point @ that.

 

[SteveDungey]

Well,

Taking off the old backplate the guy who installed it kindly left the colour coding written in pencil on the wall.

You can just see a bit of it in the right hand cut out in the photo.

Colours/legend exactly met that for the new backplate, so it's all fitted now.

Programing etc. all worked, just don't know if the system works as I'm waiting for the new combustion chamber insulation to be fitted on Friday, (found old one damaged during service).

That's when the old programmer packed up, turned off electrical supply to boiler and when it was turned back on again it was fried.

I also saw that the wires were tinned, and as they needed cutting back to fit the new backplate I dutifully got the solder all ready, only to find that the wires are already tinned.

And yes, the wiring centre is in a separate box just below the programmer.

And I think you are right about a tight bastard too, the new boiler was put in when we had an extension to the house, and this is not the only cringeworthy thing he left.

I'm going to get this sorted by a proper electrician, but this is how he left the connection to the boiler, we didn't part in the best of terms......

 

[Whitespirit66]

Quite literally, shocking. Probably best to get a heating engineer in, as some sparks are thrown by ch wiring. Though if it's just a tidy up in this case, may be ok.

 

[Echo the husky]

Here's todays example of terrible central heating wiring. FFS