Be aware.
The Drayton Wiser, OpenTherm control feature is quite limited.
Only ‘Kit 1’ supports OpenTherm and only for Combi - boilers.
Read the Wiser online info for full details.
I have a Wiser system (neither Kit 1, nor using a combi-boiler) and it works quite well.
(Obviously, no OpenTherm control).
The HA integration is marvelous for additional info/control and presentation.
I’ve no experience of other smart heating systems but I guess it would take some beating.
Hey all,
Yes, back in the living 
Just wanted to share something I found very disappointing with Wiser. Ive just completed the installation of two bathrooms, with dual fuel radiators and my plan was to use the Heat Switch to control the radiator. Alas, what wasnt totally clear to me, was that you MUST have a room stat in the bathroom for the heat switch to work.
This makes sense for a plinth heater, but does not make sense for a towel radiator, whose job is to heat towels not the room , and the elements in the radiator have their own thermostat…
Quite disappointed and alas its all installed, boxes in the skip so cant be returned… maybe ebay…
@robertwigley , is this your understanding too?
Im currently looking at alternatives and will likely resell the heatswitch(s) i have
Oh, that’s a pity. Yes, the Electrical Heat Switch needs a Room Thermostat. It’s not a standard on/off relay and is controlled by the room temperature.
If it’s for towel rails rather than an electical appliance that heats the room (i.e. plinth heater, space heater or UFH), then you would be better with something like this or this (dependent on the load) and running it outside of Wiser via Z2M or ZHA, the second of which I am using to control my immersion heater.
thanks Robert, I’ll check it out.
I called wiser today and they were very unsympathetic and I also send in a “moan” support request…
I’ll checkout the first one (Mode smart), I also found this Electric Towel Rail Wifi Timer With Fused Spur Timerswitch
, its controlled by Tuya , so I need to check if that integrates with HA
Moan Moan., was looking forward to using the heatswitches as they’d act as Wiser repeaters too…
Anyway, its a warning to others here, I dont think the wiser heat switch is suitable for electric towel radiators… The idea of putting the room stat in a humid bathroom doesnt sit right with me…
On the bright side, the Room Stat provides a humidity value.
You could use that to regulate the ventilation and control condensation?
Tuya can be integrated, but the standard integration is cloud based and it’s a bit hit and miss as to what is exposed. I have a portable AC unit that is Tuya based (there were no other options than Tuya at the time of purchase and probably still aren’t) and the controls are very basic. There are HACS versions Local Tuya and Tuya Local, but I believe they are quite fiddly to setup (I haven’t bothered as it only gets pulled out and used a few days each year). Personally I would stick with a Zigbee based solution, assuming you have a separate Zigbee coordinator and network.
I can’t see any reason why a Room Thermostat would have a problem in a bathroom. I have an Aqara temperature and humidity sensor in my bathroom for controlling the extractor fan. However, if the towel rails do not put out enough heat to heat the room, only to warm/dry the towels, then it doesn’t sound like the Electrical Heat Switch is suitable for your needs regardless.
Amazing community and discussion. Very impressed.
Has anyone used this with an opentherm combi boiler and which make did you go for, as I’m still trying to decide.
Pity about the dry ufh needing an additional room thermostat. Will see how much that adds to the cost.
The wet ufh controller is too expensive when compared to Heatmeiser so I might opt for that instead. Such a pity but still trying to decide.
thanks again.
There are often fairly large discounts (30% or more) to be found on Wiser products if you shop around and/or are willing to wait for a sale or until Amazon Prime Day, which is in July. Don’t buy at full RRP, especially the Room Thermostats (which are incredibly overpriced). I got most of mine for around £50 off eBay. Also, as you need the Electrical Heat Switch, a Room Thermostat and the Remote Temperature Probe for dry UFH, check whether you are cheaper buying a bundle, or individually. Sometimes deals on individual items can counter-intuitively be significantly cheaper than bundles, as the prices/deals seem to fluctate with supply and demand.
No affiliation, but for a retail store (i.e. excluding marketplaces like eBay), I have found that the prices at The Smart Thermostat Shop are among the most competitive especially when there are no deals running. As always do your usual due diligence checks elsewhere, as this is not guaranteed.
If you already have a zigbee2mqtt network you can pair the heat switch with that and use an aqara temp sensor to supply the temperature reading.
Hi,
Off topic, I know but…
In my experience of Tuya, the Tuya Local HACS integration is far superior to the others. I have used them all. The native Tuya integration is slooow to respond, and I found with the HACS Local Tuya integration, the devices kept going unavailable requiring a HA restart to get them back. There are warning messages output to the log as well on start up.
I have non of these issues with Tuya Local and the setup is very easy if you have the Smartlife app configured on your phone with the devices already set up in it. Its a simple matter of using the App to scan a QR code the integration throws up when configuring the integration.
Thanks. I may have to give that a try if the weather actually gets nice enough to pull out the AC unit this year. 
To be clear, it is the hacs integration by this author xZetsubou and is this one. hass-localtuya
It’s a complicated topic as everything is so fragmented. I’m by no means an expert of any sort but I believe that most 3rd party controls aren’t great at opentherm as they often unnecessarily request higher flow temps when they’re not needed. I believe the exception to this is Nest whose opentherm algorithm is much better but then you don’t get many other features such as TRVs. Take a look at urban plumbers on YouTube. You’ll find in a number of older videos he uses nest with intergas boilers.
Drayton did publicly state (I referenced it somewhere up the thread) that they were working on improving the OpenTherm implementation this year, but nothing has materialised that I am aware of yet. Maybe it will appear in the Autumn before the next heating season starts.
this shop seems to be half the price for room thermostats compared to amazon and cheaper than smart thermostat shop.
If I can find a cheap place to do the £290 ufh wet controller, then I might be able to go with drayton for everything, instead of mixing with Heatmeiser for UFH (they don’t need separate thermostat and floor sensor for dry & 1/3 price for their ufh controller/hub).
RS Components are a well known and reputable company that have been around for years. That’s a very good price on the Room Thermostats! You probably won’t beat that by much even when there is an official deal running.
Separate from a schedule, would something like below work based on motion sensors:
ADHOC
Motion sensor triggered in room = Boost that room TRV to X max temp for an hour (keep X temp repeating each hour if motion sensed).
Motion sensor not triggered for 10 min (people have left the room) = Turn off TRV in that room.
SCHEDULED TIMER
Yes, you could do all three items using HA automations, although I am not sure I totally understand item three, as that would just swich off the TRV and then trigger it again based on motion.
Having said that, and I’m sure someone will correct me if I am wrong, but you may want to reconsider using motion as it is unlikely to be the most efficient way to heat a room; it will likely be constantly turning the heating on and off, which is not efficient.
UFH Controller from Amazon Warehouse (packaging is damaged) for £215.
https://www.amazon.co.uk/CCTFR6610-Underfloor-Heating-Distribution-Regulates/dp/B0BB35PGX7
The CamelCamelCamel price tracker indicates this is likely to be the cheapest you will find it without waiting quite some time (if it ever returns to previous lows).
Thanks all,
So for my towel rads Im looking at either
Before i send them to Ebay, anyone need a Wiser
heatswitch?