Just moved into new house with Drayton RF SCR... errrm!

[lardbros]

Hello, just joined here to ask a question about my new central heating system in my house.

There is a Worcester Combi Boiler (with an MT10 timer unit), and a Drayton Digistat RF601. I've tried EVERYTHING i can think of, but thought I'd try you clever lot in here before calling anyone out.

Basically... The thermostat seems to override the timer unit on the front of the boiler. If the timer is set to ON, heating is on all the time. If it's set to OFF it's off all the time... but if I set it to TIMER, even if the switches are all set to off the thermostat will still fire the boiler up if the temperature calls for it.

Are there any quick ways of testing the wiring etc to see if it's done correctly? I have a basic knowledge of these things, but am not stupid, so am certain I could have a go.

If there are any questions you need to ask before giving a full answer, please do! I can also post any photos of the wiring inside the SCR unit if need be.


Many thanks for your time guys and gals!

Tim

 

[bobloes]

I am not familiar with the units you have but I did do the wiring for my own system after a 'professional' had installed a new boiler and connected the new control unit. I did this eight years ago and the system has worked perfectly ever since. However it would have been impossible to do without the appropriate wiring diagrams for the boiler, control unit and three way valve. If you can get hold of those then it is a relatively straightforward job. One word of warning - I believe that even by taking the cover off the boiler, even if you do nothing to the gas supply, you are breaking the law. Good luck.

 

[D_Hailsham]

The wiring is wrong. You should have four wires connected to the SCR: N, L, 1 and 3. I suspect that you have only three: N, L and 3, with a link between L and 1.

 

[mysteryman]

You need to select permanent ON at the boiler for the Digistat to time it.

 

[D_Hailsham]

You need to select permanent ON at the boiler for the Digistat to time it.

The OP has a thermostat, not a programmable stat.

 

[lardbros]

The wiring is wrong. You should have four wires connected to the SCR: N, L, 1 and 3. I suspect that you have only three: N, L and 3, with a link between L and 1.

Yep... spot on! That is exactly what I have...

How can I go about sorting this then? It seems it must have been like this since the day it was put in... but has driven me mental already!

Am I allowed to fix this? Surely it's pretty simple isn't it?


Thanks VERY much for all the responses so far, it is GREATLY appreciated.

 

[lardbros]

oops, duplicate post... sorry

 

[lardbros]

You need to select permanent ON at the boiler for the Digistat to time it.

The OP has a thermostat, not a programmable stat.

My digistat doesn't have a timer, it's just a dumb temp sensor unfortunately. It may be worth investing in a timed thermostat, but for the time being it would be worth fixing this issue I reckon.

 

[lardbros]

Sorry to bump this thread, but would be very nice to know of a fix for this...

So, if I have this:

I suspect that you have only three: N, L and 3, with a link between L and 1.

As D_Hailsham correctly stated... how can I fix it?

I've noticed the cable from the boiler has quite a few wires that have been cut off, and the remaining few have been used in the SCR. I'm guessing I need one of these cables, so will have to strip the whole lot backand connect from scratch... but which one will I need? Not sure what colours they are off the top of my head, but one is yellow. (not much help probably.)


Thanks in advance for any help!

 

[Jezclayton]

Presumably the RF601 receiver is located adjacent to the boiler so running a new length of 4 core flex would be easy. Wiring is as per the installation manual for your boiler and Digistat unit, copies of which can be downloaded from the respective websites.

 

[lardbros]

Presumably the RF601 receiver is located adjacent to the boiler so running a new length of 4 core flex would be easy. Wiring is as per the installation manual for your boiler and Digistat unit, copies of which can be downloaded from the respective websites.

Yes, it is right next to the boiler. I have a very basic wiring diagram, but it doesn't make much sense... I don't have a clue what the 1, 2, 3, 4 stuff if on about, and what colour wires need to be connected to the respective numbers/letters. Surely N is Neutral, and L is Live...

I'm not planning on replacing the entire cable, but just strip the old one back slightly and re-wire just the SCR Unit. Just would love to know what all the coloured wires are for?

Thanks

 

[D_Hailsham]

So, if I have this:

I suspect that you have only three: N, L and 3, with a link between L and 1.

As D_Hailsham correctly stated... how can I fix it?

You need a four core cable between the back plate and the boiler.

I've noticed the cable from the boiler has quite a few wires that have been cut off, and the remaining few have been used in the SCR. I'm guessing I need one of these cables, so will have to strip the whole lot back and connect from scratch... but which one will I need?

You can use this cable, provided there is some slack in it at both ends. If not you will have to run a new cable or relocate the receiver.

The other end of the cable will be connected to the boiler. Can you find the other end and post which terminals the cable is connected to?

 

[lardbros]

Fortunately there's plenty of slack in the cable, so would prefer to use that I think. Am I okay to take the front off the boiler? Not illegal or anything is it?

I'll take some photos of both ends of the cable and let me know what you think...

Thanks!

 

[D_Hailsham]

Am I okay to take the front off the boiler? Not illegal or anything is it?

The front cover is only cosmetic, so I would go ahead and remove it.

I'll take some photos of both ends of the cable.

The pics must show the terminals each wire is connected to.

 

[Jezclayton]

I have a very basic wiring diagram, but it doesn't make much sense... I don't have a clue what the 1, 2, 3, 4 stuff if on about, and what colour wires need to be connected to the respective numbers/letters. Surely N is Neutral, and L is Live... Thanks

Are you sure you want to do this as it doesn't appear electrics are your forte. At best you could get the boiler working as you want. On the other hand you might fry the board and wish you had got an experienced professional in to do what shouldn't cost much more than £50. At worst you could kill yourself which will leave your family wishing you had got someone in.

It's a sad fact that even experienced professionals have been known to electrocute themselves when working on boilers and the related control wiring. What you are about to embark upon is potentially dangerous so please don't go there unless you are sure you know what you are doing.