Honeywell BD91 (used with evohome) - "Min 30cms apart"

[Rameses]

A quick note to all.

The BDR91, is a wireless relay box commonly used with the Honeywell evohome & single zone thermostat systems. We see A LOT of installs where there are a couple of boxes (i.e. like in airing cupboard where stored hot water is), people (professionals included) are mounting them side by side.

Please don't.

In the instructions - Honeywell recommend and state 30cm distance between relays. This is to reduce the (unlikely) possibility of interference etc.

[G4RHL]

In trawling through the forum I have come across your advice re separation distance for the relays. This I fully understand. I was wired up shortly before Christmas. All works OK but I notice that the relays - heating, hot water & temp sensor - are all well within 30cms of each other, indeed not far off touching. I must take some of the blame for this as if my brain was in gear at the time it would have been an obvious thing to me without even reading the advice on it. All does though seem to be working OK. I am tempted to set to and relocate them so that there is plenty of distance between them as this will be a simple task of putting in longer cable lengths. Before I do it, is there anything I should look out for that might tell me I have proximity problems with the relays?

[Rameses]

To be fair the advice we give is a catch all. That is to say they are robust bits of kit. If they work and you are not experiencing problems then I would be inclined to leave as is. Some evohome installs can have many many BDRs (the system is very expandable) so this is where this advice is really more apt.

If its not broken, don't fix it :-)

[G4RHL]

Thanks. Bit of a pain putting longer cable lengths in to achieve the minimum separation anyway - it's a confined space.

[HenGus]

Thanks. Bit of a pain putting longer cable lengths in to achieve the minimum separation anyway - it's a confined space.

My installer complied with the criteria; however, he told me that a lack of space in his airing cupboard meant that he had no option but to put the 2BDRs and the CS92 in a line and edge to edge. He has had no issues whatsoever. Conversely, I have had an issue this week with both valves going offline with comms faults. The initial consensus was that, based on the number of faults, the HWV BDR was the culprit. This logic was dispelled when the heating valve BDR had a spate of comms failures but the HWV BDR remained online. As both BDR faceplates have now been replaced, then the culprit may never be found.

[The EVOHOME Shop]

We have had multiple calls about evohome RF issues and once the BDR91's have been 'relocated' the problems have ceased.

I am slightly OCD in everything I advise and do. In my eyes, it would be like someone saying 'don't put a knife in a toaster to get stuck bits of hot cross bun out' some people do and get away with it... I prefer to not force hot cross bun into the toaster in the first place!

Everything is designed, tested and built to work correctly at the recommended values, no matter what the item or the parameters... To go against 'manufacturers' instructions seems counterintuitive.

[HenGus]

We have had multiple calls about evohome RF issues and once the BDR91's have been 'relocated' the problems have ceased.

I am slightly OCD in everything I advise and do. In my eyes, it would be like someone saying 'don't put a knife in a toaster to get stuck bits of hot cross bun out' some people do and get away with it... I prefer to not force hot cross bun into the toaster in the first place!

Everything is designed, tested and built to work correctly at the recommended values, no matter what the item or the parameters... To go against 'manufacturers' instructions seems counterintuitive.

Yes, I agree, and looking carefully at my layout, it is fully compliant. The BDRs are arranged vertically (30cms apart) with the CS92 situated below the HWV BDR. The Controller is wall-mounted (and it has never been moved) about 5 ft up on the hall wall. My airing cupboard is above it displaced about 3ft to the left, so there is a clear line of sight (of about 5ft distance) between the controller and the 2 BDRs.

However, when RF problems start happening 6 months after the install and, up to this point, the only issue has been a brief comms fault on one valve during a particularly bad thunderstorm, then moving BDRs to different locations may prove problematical in itself. Two days on, with new BDR faceplates, there are now no comms faults showing in the faults log, and the occasional one minute pump run that I could hear overnight has stopped. The latter only started happening when the comms faults appeared when there was no demand for heating (all TRV targets set very low) and HW demand off.

Rameses suggested that I should re-set the controller by removing the batteries for 30 secs. Will this clear the pages of faults? What, if anything, will happen to all the zone settings?

[G4RHL]

Do the batteries come out of the controller? On the back of my control panel there is what looks like th cover for the batteries but if I remove it there are no batteries in there, only the circuit board. I guess the batteries are not meant to be removed.

[The EVOHOME Shop]

Do the batteries come out of the controller? On the back of my control panel there is what looks like th cover for the batteries but if I remove it there are no batteries in there, only the circuit board. I guess the batteries are not meant to be removed.

Take the front coloured fascia off (white, silver or black depends what you have fitted) and the batteries are behind this.

[G4RHL]

I have done the right thing this afternoon and separated out all BDR91s so that they are all more than 30cms from each other as well as being 30 cms from the Hot Water sensor. Have had no problems before but must be better to play safe.

[top brake]

Here's what it says in the manual

[HenGus]

After a 3-way exchange between my installer, Honeywell and myself, my BDRs will be moved on Monday to the top of my airing cupboard well away (i.e; a lot more than 30 cms) from anything metallic or electrical. Time well tell if this fully resolves the actuator comms issue that I have been experiencing.

[top brake]

After a 3-way exchange between my installer, Honeywell and myself, my BDRs will be moved on Monday to the top of my airing cupboard well away (i.e; a lot more than 30 cms) from anything metallic or electrical. Time well tell if this fully resolves the actuator comms issue that I have been experiencing.

It does say minimum 30 cm. so the further the better.

[VvrooomM]

I've got everything 30 cm apart but am still getting 'heating valve actuator' fault on the HW. This follows a factory reset and repositioning. I've spent hours of my life on this gear, NO, make that days!!

[top brake]

Please post up a picture of the relays.

I've got everything 30 cm apart but am still getting 'heating valve actuator' fault on the HW. This follows a factory reset and repositioning. I've spent hours of my life on this gear, NO, make that days!!