Honeywell Evohome Installation Help

[sambancroft]

Hi All,

Firstly abit of background:
I live in a 2015 built house, which has two thermostats (one in the living room, and one in the bedroom), and 10 radiators with two different fittings. I've identified that two of the radiators will need their TVR's replacing in order to be 'evohome compatible'. My boiler is an 'Ideal Logic Combi 35', (info found here: http://www.acwilgar.co.uk/Boiler-Manual-PDF/Ideal/Logic-Combi-Installation-Manual.pdf)

I'm currently trying to wire in the supplied 'BDR91', which I am assuming should replace one of the two thermostats I have - I'm attempting to replace the downstairs thermostat with this.

The current thermostat looks like:

and is wired in as:

The BDR91 looks like

Would I be able to get your advice into how to wire the BDR91 in? I have tried to replicate the wiring in the current thermostat however this didn't seem to 'ignite' the boiler when I turned up the temperature on one of the radiator evohome units.

More than happy to supply additional photos or information if needed!

Thanks in advance for all your help.

 

[stem]

The wiring diagrams showing the internal 'switch' are printed on both thermostats. So it's just a matter of moving all of the wires across like for like.

Grey Wire in Danfoss N goes to Honeywell N
Brown Wires in Danfoss L go to Honeywell L (The right L terminal is provided for the loop)
Brown loop Wire in Danfoss 2 (Com) goes to Honeywell A
Black Wire Danfoss 3 (N/O) goes to Honeywell B

 

[Dan Robinson]

Popcorn at the ready.

 

[sambancroft]

Thanks for that - I previously wired it into B and C so it didn’t work!

I’ve now got an issue which I was hoping would be fixed by installing the evohome in place of the downstairs thermostat - whenever the downstairs thermostat commands the boiler to be “on”, only two radiators in the house turn on (both upstairs). In order to get any of the other radiators on, the upstairs thermostat must be manually switched to on.

Any ideas on how I can solve this issue and get the downstairs thermostat to control every radiator in the house?

 

[muggles]

Sounds like a wiring fault, possibly with the original installation. You need to find your wiring centre (usually in the airing cupboard) and wire your BDRs into there, correcting any faulty wiring as you go

 

[Dan Robinson]

Sounds like a diyer has screwed up their S plan plus.

 

[stem]

Could even be a plumbing issue.

 

[Dan Robinson]

Nope.

It might be an issue with the original wiring, but....

 

[sambancroft]

Hi guys, as we have a combo boiler there’s no airing cupboard! Only wiring I can see is at both thermostats,and the cupboard under the stairs (see attached photo). Would it be in the boxes there?

 

[muggles]

I think this is the bit you need

 

[stem]

Could even be a plumbing issue.

Nope.

I was thinking that having just two radiators connected to one of the motorised valves seems unusual. Something no doubt is wrong with the wiring, but I'm not convinced that's the only issue. Perhaps more will be revealed in due course.

Whenever the downstairs thermostat commands the boiler to be “on”, only two radiators in the house turn on

 

[sambancroft]

Apologies about the delay, I've been away all week! I've revealed what's under the white bit, and it looks as attached. Any ideas?

 

[sambancroft]

Evening all, any ideas? Currently stuck with half an evohomed house! If it is a plumbing issue, would that be something I’d be able to sort out or would I need a professional?

 

[stem]

Personally, I don't think you will be able to solve this over a forum. For example you have posted a photo of some wiring terminals but without knowing what is connected to the other ends of each one of the wires, from a trouble shooting point of view it doesn't really help much. The same is true of the pipes that disappear into the ceiling.

You say the house was built only 3 years ago. If it didn't work properly from new, then why didn't you get the builder in to sort it? If it did work properly then what happened? did you disturb or alter something? If so, and can explain in detail what was done, someone might be able to help. Otherwise I believe that it will probably be a case of having to get someone 'in' who can examine the system to troubleshoot it.

 

[hellcat_uk]

Evening all, any ideas? Currently stuck with half an evohomed house! If it is a plumbing issue, would that be something I’d be able to sort out or would I need a professional?

Hi, about to bring my CH system into the 20th centaury so browsing to see if there are common pitfalls to avoid.

If you're evohoming all your radiators, you might want to get a plumber in to remove them two zone valves, or replace them with gate valves for future maintenance. The BDR91 in your system should act as a bridge between the controller and the boiler. It shouldn't be opening zone valves and you're bound to run into undesired behaviour if a rad calls for heat through evohome but is on the circuit controlled by the other valve. Having this rewired should remove the need for what we would in IT call that 'undocumented s***'. Seriously, would it hurt on a multi-thousand pound system to use some DIN rail boxes and cable number rings?