Hoping someone can help me figure something out, apologies ahead of time for the long post!
I have underfloor electrical heating which is controlled by this old, analog thermostat:
It's a single pole, line voltage thermostat that I'm trying to replace and there aren't that many smart versions around of those, especially none that can support a very high load over 4kW.
Basically as far as I understand it, the thermostat closes the loop of the only 2 red wires that come out of the wall when the temperature is below the temp setpoint. The load of the actual underfloor heating wires is wired in series and aren't available where the thermostat sits. The white wires in the following pic are actually part of the thermostat wiring setup and as such don't come out the wall just to make things clear:
1 of the 2 thermostats controls 2 heating circuits but I only ever have 1 of those heating circuits engaged as I turn the other one off at the breaker. The reason for leaving one of the circuits unused is that this circuit heats up an 8m long freezing cold hallway and the entrance hall near the front door. The problem is that the thermostat is located next to the front door and obviously never detects that the second cicuit (for the living room) is heating up and since none of the warmth comes through to the front door, the thermostat is basically always on. With underfloor heating, it is of course not economical to have the system running non-stop as it is intended to start cycling on-off once it reaches its setpoint.
The size of the circuits that I do use is pretty large: one room is roughly 24sqm (dining room) and the other 64sqm (living room). If I calculate at 150W/sqm (which is something I found online as a reference for calculating the load from an underfloor electric heating mat) then one circuit would draw 3.6kW and the other a whopping 9.6kW! I'm pretty confident that no heating mats were used however and that not all the space in the living room has been covered with heating wire (too many cold spots for that to be the case when the system runs) so I assume this number to be a lot lower than that. However, I reckon it will still be higher than what the current smart thermostats will be able to handle. Maximum I've seen is the Sinopetech one at 4kW.
Soooo, I was thinking about a couple of solutions, both of which would have me using a virtual thermostat instead based on agreggated temp sensor data:
is there a zigbee switch that I could use to couple the 2 wires at the wall where the thermostat currently sits that would be able to sit inline without frying?
!
As you can see the smaller circuit which sits next to the timer (dark grey switched to off) is connected to a 20A contactor.
The 2 other heating circuits (first one switched off, second one on) both sit on the following 24A contactor (other pic wasn't clear enough for that one so I've taken a close-up) :
the 'stat is likely switching the contactor coils, so current through the 'stat would be very small. but you need to be sure before playing with it. (i.e. turn everything on and measure the current in those wires with a tong meter. if the current is anything more than 1A then its powering more than a couple of contactor coils).
hire/beg a favour from a sparky is my firm recommendation, you can cause a fire if you don't know what you're doing.
if my assumption is correct then provided there's neutral in there somewhere just use an inline switch such as the new Ikuu inline switch (product code SISW01), and cover the hole with a Zen thermostat (zigbee version) for a nice-looking, controllable 'stat.
Do you happen to have bought any Mercator bulb too? If so, did you manage to get them working? I bought some RGB ones and added them to HE through my Hue bridge integration but the hueRGBW driver didn't work with the bulbs at all so in the end I removed them from the Hue app and added them directly to HE which then worked as expected with the generic RGBW driver. This isn't quite ideal as I was hoping to have all my ZigBee bulbs on a separate network via the Hue bridge.
I'm curious about this too. Which bulb did you get? Did you try the Cocohue integration instead of the built in one? I got all my lights on hue bridge so prefer it that way too.
Thanks for suggesting using the Cocohue but I just finished testing and it didn't work - I can turn the lights on and off & set level but can't change colours which is a deal breaker for me (to a certain extent) as all globes/LED strips I still need to buy are going to be RGB.
Here's my order summary:
I needed another 13 GU10 ones but I'll have to assess my hub's capacity (maxes out at 32 bulbs I believe) before ordering more since I won't be able to manage them through my Hue bridge.
@saxnix As I mentioned on the post, I managed to get them working directly through the native HE driver like you did but this is not what I was seeking to achieve as some bulbs can cause problems with your ZigBee mesh if running on the same network as your battery powered endpoints.
i believe the main culprit for what you describe is that some bulbs (e.g Hue, Sengled and others) support ZLL instead of a full ZB3.0 stack. These Ikuu ones are ZB3.0, so I expect them to behave on your core (HE) mesh. I have verified that the Ikuu DGPO routes fine, by forcing another battery endpoint to re-join and it routed nicely thru the Ikuu. I didn't specifically test on the bulbs to be honest though, because the spec sheet was identical, and Mercator designed the range in one go (not piecemeal), so I expect the stacks to be identical across the range. now that i've said all that, i fully to expect to be proven wrong as i complete further testing across the range - which is currently over 130 products.
its nice to have a good range of products from a reputable supplier in Australia for a change...
ZB3.0 should cover ZLL tho. 48 of my 55 lights on my hue bridge are ZB3.0 lights while the rest are Hue and IKEA's ZLL. They all work fine on hue and on HE via the Cocohue integration.
@hpgurgel mind sending me a pic of how the downlights and LED strip controller look like?
exactly...however the point is that @hpgurgel can indeed use the native HE driver on his HE mesh without causing problems on his mesh, which he was rightly concerned about avoiding.
This is great news @saxnix I should be able to order more lights then
Thanks a lot for the info @sanewton72 - To be honest I wasn't aware of the difference between the ZLL and ZB3.0 so I am glad you highlighted it, that's much appreciated.
Due to the lack of smart lighting knowledge, I bought a number of Brilliant Smart and LIFX bulbs last year - I am happy with the LIFX ones as I managed to get them working fine with the community based driver but the Brilliant ones I am definitely getting rid of. I even managed to extract their Local Key and product ID but I couldn't find and generic driver to make them work with HE & you can't flash GU10 and E27 bulbs with Tasmota either. I actually considered commissioning an HA instance on an old laptop I have here as it has a local Tuya integration but I never got around to.
yeah - i also have a "smart home product graveyard" (aka back of the cupboard) that is far too populated for my (and my accountant's) liking.
the only way i can rationalise it is by accepting that HA has been a 'maturing' market
That's true. ZB3.0 lights should work fine on HE. Reason I stayed on hue is:
Wife has been using it for years before HE came along and I'd like to keep the WAF, and
I find hue's app interface to be the nicest in terms of setting scenes and colours. There's plenty of 3rd party apps that help create dynamic scenes easily. HE's colour and scene setting is just clunky. I only use it for automations... I didn't even bother with HE dashboards
yeah agreed - I also still run Hue for those reasons (as well as isolating the ZLL devices). it works - Hue has been ROCK SOLID and the dimmer battery life is insane - so can't see why i'd spend the time to change it.
but the cost of their bulbs and devices are ridiculous, so if i was starting from scratch now i don't think i would take the Hue route again...it'd be Ikuu for sure.
(caveat: i've only tested a few devices on my HE mesh, and not exactly a long time so hoping there's no nasty surprises as I go)
Were you able to get your LinkTap working? I just ordered one and home to integrate into the same you want to. I also plan to use it with drip irrigation.
its nice to have a good range of products from a reputable supplier in Australia for a change...
