Replacing analogue room stat & receiver/relay

[Lucid]

Hello gurus of the CH world. We have a Honeywell Y6630D analogue room stat and receiver/relay.

I'm not up on the terminology of boilers, but it feeds a hot water cylinder if that gives you any clues.

HW works but CH doesn't. I suspect the room stat has died. I have changed batteries in the stat, but there's still no red indicator light that would usually flash when the dial is set to a high or low temp. The receiver doesn't get a pairing signal.

I've had a quick squint at a replacement, and nearly fell off my chair. £300 for the two devices at some sellers. Blimey, that can't be right, can it?

Do I have the option to replace this with something less costly such as a digital stat kit I can pick up over-the-counter?

Location is Middlewich, Cheshire.

Thanks in anticipation.

 

[RandomGrinch]

Afraid I'm not a guru, but here goes!

As you mention a hot water tank, have you ruled out any problems further along the line - does the C/H turn on via a short press of the override button on the front of the HC60NG receiver?

If that works correctly, then you have some options.
You could replace like for like and pair with your existing receiver, or have a look for other HC60NG/R6660D compatible thermostats.

Alternatively, there are a wide choice of wireless stats that would need a receiver change, or (as many do) you could go for a smart system that replaced your existing programmer; this is often a straightforward swap that would also give you smart control of the hot water. The receiver would simply be bridged out, or decommissioned.
If you'd like to explore this further, let us know the model of your programmer.

 

[CountryFan]

Were they good quality alkaline batteries? Have you tried a rebinding procedure? I can’t get on Honeywell/Resideo with my iPad (outdated now) but they have a rebind page, I’ll get the link, also I found the following if you want to try it?

• First, reset your HC60NG and then press and hold the teach-in button of the HC60NG for 5 sec to enter into the teach-in mode. The red LED flashing at 0.5 sec on/0.5 sec off confirms the teach-in mode has been entered.
• Press the teach-in button of the HCW 80 to send the binding signal to the HC60NG. The red LED of the HC60NG is switched off to confirm a successful teach-in operation.

KCS UK

 

[RandomGrinch]

First, reset your HC60NG

Thanks, I realised after you posted that I called the receiver the newer BDR91, rather than the HC60NG.
They are compatible, but I've edited my post for clarity!

 

[CountryFan]

Thanks, I realised after you posted that I called the receiver the newer BDR91, rather than the HC60NG.
They are compatible

I didn’t realise that, good to know. @Lucid I sometimes get spare BDR91 receivers should you want one for postage cost or next time I’m in Middlewich, not sure when that’s likely though? Or if none of what I suggested works, and you wanted new, then there’s plenty of options available.

 

[Lucid]

Hello, and thanks for the info so far.

Answers to questions asked so far:
Batteries - Duracell and also a new set of Energiser (my preferred choice as they don't leak, unlike Duracells
Override on HC60NG receiver - Yep. Green light. Heating set to +1 hr. Pump and boiler fire. Rads get hot
Programmer - Honeywell ST9400C

The KCS link was very useful, thank you @Stuckinarut From there I've found that the only compatible room stat for the R6660D is the HCW80 (link to page). Any change of room stat would need a change of receiver/relay too, and from what I understand, there's a difference in the wiring. My R6660D has four wires. Live and Neutral, then two switched live wires(?)

I've read threads in this forum where people have bought new stats and RX/relays, then found they use two wires and ended up stuck because their old RX/relay was a four-wire system. I'd want to avoid that hassle if possible. You know how it is, SWMBO won't be happy if I get halfway through the job and then have a delay whilst new bits are sourced.

Something else I'm very aware of is my ignorance on heating controls in general. What does a digital stat bring to the party that makes it worth the effort swapping from an analogue dial?

Something else I've stumbled across is a recommendation for the T6R kit, and I think that might be based on its ability to link with Google/Alexa. I can see the advantage in being able to access the heating and hot water controls when I'm heading at odd hours due to work. Remote access is something I've got with the door cams, and I do it for customers with their CCTV. However, we never got into the Google/Alexa ecosystem at home. It just seemed like a lot of faff for what ends up as a glorified weather station and a potential point of failure if the internet goes down. Am I missing out? Is it really worth me adding an Alexa device just to enable remote access to the CH system?

Any enlightenment you can offer would be much appreciated.

 

[RandomGrinch]

From there I've found that the only compatible room stat for the R6660D is the HCW80 (link to page).

That may be the official line - even though the HC60NG was supplied with a few other stats, such as the CM67z etc.
The main difference between the HC60NG and the BDR91 is bi-directional radio on the newer model - which isn't much of an issue with simple on/off control to the boiler, but it does make sense to renew it.

I've read threads in this forum where people have bought new stats and RX/relays, then found they use two wires and ended up stuck because their old RX/relay was a four-wire system. I'd want to avoid that hassle if possible

Four wires at the stat location gives you a lot more choice of what you can fit. Many new builds are stuck with two wires and a battery powered wall mounted stat.
You have the choice of battery or mains powered wall mounted stats, or replacement by a receiver - although depending on how your system is wired, the programmer may need to be set to constant to provide a constant supply to the stat/receiver.
Which brings me to...

Programmer - Honeywell ST9400C

The ST9400c fits onto an 'industry standard' backplate, which means products such as a dual channel Hive, or a Drayton Wiser, would simply slot on - leaving only the old receiver needing bridging out.

It just seemed like a lot of faff for what ends up as a glorified weather station and a potential point of failure if the internet goes down. Am I missing out? Is it really worth me adding an Alexa device just to enable remote access to the CH system?

On top of the connectivity 'benefits', what you may be missing out on, is a smart stats ability to accurately control the house temperature - even with simple on/off relay control of the boiler, the algorithms built into a smart stat allow it to accurately control the temperature, by knowing how long your house takes to warm up. It also takes weather information from the web and from other local users, to predict how long to fire the boiler for - It's sort of like a very long period pulse width modulation control, attempting to create a steady state temperature (on/off load compensation).
The downside, is the boiler may cycle more, but there is potentially an efficiency saving to be made.

 

[CountryFan]

To answer about digital, they’re probably more accurate. As for remote access, that’s a preference really, some like the idea of being able to bring the heating on if they’ve been out and it’s cold outside, so it’s warm for when they return, similar principle as being on holiday. Apart from that not much to add to what @RandomGrinch posted above.