Cheap eBay WiFi heating controller,

Hardware
42

Ok, let’s try to avoid electrical shocks…

First : my boiler has an important difference from yours, the control circuit is 24V, not 220. And I don’t have the same model of thermostat, but a specific version for gas/fuel boilers.
@anon43302295 : could you post a picture of your model ? Right now, I’ll assume you have the same as cooljimi84 ?

So, first thing, power your thermostat. This is easy, live on 4, neutral on 3. (or the opposite, that’s not much of a problem)
Now, your boiler OUTPUTS 230V on its terminal 1. And it RECEIVES 230V on terminal 2.
The thermostat OUTPUTS 230V on terminals 1 and 2 : it’s live and neutral. Nothing can come from your boiler on those !!
:warning::warning::warning:If you plug in and out from the boiler to these terminals, you’ll most likely blow the thermostat, maybe some fuse in your installation but probably nothing on your boiler (that’s the only good news here !). Just because you’re gonna SEND 230V to your thermostat output…

What could work, is @cooljimy84 connections. Use the controled live terminal (1 on the thermostat) to send 220V to the control input of your boiler (terminal 2).

In fact, you have a thermostat for an electrical heater, terminals 1 and 2 are designed for a load.
The boiler needs a simple switch between terminals 1 and 2, because it provides the load (230V live).
When plugging only the live output (term 1 of thermostat) to the loop input of the boiler (term 2), you just provide the 230V it waits for to start heating. And forget about the 230V it outputs on terminal 1.
I may not work if :

  • the boiler checks output vs input to prevent electrical shocks on the thermostat : if 230V comes in with no load on the output, it could enter a security mode
  • the thermostat has a security on the controled output, if it sees power going out of the live terminal and none returning on the neutral one.

The other way of doing it, is to plug the live and neutral controlled output from the thermostat (term 1 & 2) to the main live and neutral input of the boiler; let the link between 1 & 2 on the boiler. When the thermostat turns on, it will power the boiler that should start ?

1 Like
43

It’s a ‘Baxi combi 105 he’

When I look at the instructions for attaching a nest to the boiler it follows exactly what I said, piggy back of live/neutral and points 1&2 connected across the load wires.

I was 100% confident about installing it in that manner until I saw @cooljimy84 's picture and can’t work out how it’s passing the on signal to the boiler. Like you say if it’s just a 24v line then it’s going to go bang.

I can’t attach this as a midway for overall power to the boiler because it’s a combi so it heats water on demand so the boiler itself always needs to be on, just the heating needs to be switch/stat controlled.

Also, if you read the description on the label that I posted a picture of earlier it does say that the pin 1 goes to the thermostat control and then the switched output from the controller goes to pin 2.

Which only begs the question, can the thermostat handle 220v through those two ports :smile:

I’m at work atm, so if anyone has the measly bit of paper to hand that came with the thermostat as ‘installation instructions’ can have a look and see if it says anything about the maximum load on pins 1&2?

44

Spoil sport :stuck_out_tongue_closed_eyes:

45

Sorry I got rather carried away and didn’t think other people were playing along at home.

If you are in doubt, ask a qualified technician to come help, prob be an hour or so. Best to pay and get it right and not bed dead…

46

Just added this to mine, just need to work out how you added extra weight to the sensors you wanted
(was that the “float * 2 + states.sen…” bit ?)

Also how if you change the “states.input_number.consigne_haut.state” to republish the change to the thermostat, or do you just let the automation turn it back down ?

47

I thought about the thermostat reference.
But if I look at the ebay description in the 1st post, it says " Thermostat Electric Heating" so it’s consistent with @cooljimy84 picture. It’s designed to provide power output. Not to close a loop for a boiler.
The one I have for a boiler is different in the back, so the loop I connected to terminals 5 & 6. Terminal 1 and 2 output 230V, depending on the thermostat status :

image
image950×480 35.6 KB

Even if they say a 24V boiler ain’t compatible, it works for me. A 230V loop should also work with terminals 5/6.

You should just try to connect live from thermostat to the input terminal of the boiler (terminal 2) and it may work.

48

Should we be worried that he didn’t post today ? :thinking:

49

I am still alive - but in fairness I haven’t tried to wire the thing in yet.

I’m thinking there’s only two possible ways to wire it in, I was going to draw them out for ease of reference but I’m terrible at art so I’m not.

So…

If we consider the points on the THERMOSTAT to be 1 2 3 4 as (where 1 is L1, 2 is N1, 3 is N and 4 is L) per @cooljimy84 's picture

Then we consider the points on the BOILER to be L, N, E, Out and In (top to bottom on my picture, so L is live, N is Neutral, E is earth, Out is ‘1’ and In is ‘2’)

Still with me??

Ok - wiring plan 1 is

Thermostat    Boiler
1             Out 
2             In
3             N
4             L

Wiring plan 2 is

Thermostat    Boiler
1             In 
2             -
3             N
4             Out

But of course the question is now, given that your wiring diagram is different, do I just plain have the wrong connections for the boiler/thermostat and they’re incompatible?

So - the polls are open - Wiring 1, wiring 2 or send it back?

Vote now!!

:smile:

50

Yes, the weight of each sensor is multiplications to create a mean.
I’ve changed it a little bit :
> {{ (([states.sensor.temperature_158d000227327d.state | float, states.sensor.temperature_158d00022880d3.state | float, states.climate.thermostat.attributes['current_temperature'] | float] | min + states.sensor.temperature_158d000227327d.state | float * 2 + states.sensor.temperature_158d00022880d3.state | float * 2 + states.climate.thermostat.attributes['current_temperature'] - ([states.sensor.temperature_158d000227327d.state | float, states.sensor.temperature_158d00022880d3.state | float, states.climate.thermostat.attributes['current_temperature'] | float] | max | float) + (states.sensor.m_temperature.state | float)*0.1) /5.1) | round(2) }}

The main sensors (xiaomi aqara), they are in the living room and in a bathroom. They have a x2 weight :
states.sensor.temperature_158d000227327d.state | float * 2 and states.sensor.temperature_158d00022880d3.state | float * 2

The thermostat sensor has only a x1 weight, because it’s not in the occupied rooms : states.climate.thermostat.attributes['current_temperature']

Then I add the min temperature of those 3, by creating a list and taking the min of it :
[states.sensor.temperature_158d000227327d.state | float, states.sensor.temperature_158d00022880d3.state | float, states.climate.thermostat.attributes['current_temperature'] | float] | min

Weight is x1 too.

What I added : I remove the max value from the 3 sensors, same logic of list/max operator:
[states.sensor.temperature_158d000227327d.state | float, states.sensor.temperature_158d00022880d3.state | float, states.climate.thermostat.attributes['current_temperature'] | float] | max

And also the outdoor temperature, which I get from a weather sensor :
(states.sensor.m_temperature.state | float)*0.1

With a very low weight (inside temp is 20°, outside is 0° today…)

The ““states.input_number.consigne_haut.state” is the heat setpoint. You can replace it by a value, the one you want to have at home, 20°. I chose to have it in an input_number that I expose in the frontend, it’s easy to modify.
In fact, I have 2 : one “high” (“consigne_haute”) when someone’s at home, and one “low” during the night or when nobody’s home.

If you add all the expected behaviours, heating is the most complicated set of rules I have :

  • anticipate the wake-up time so that the house is warm
  • stop heating when windows are left opened
  • turn low when we’ve all gone to bed or outside
  • stay even lower when we’re on vacation
  • secure the 7° minimum even while on vacation
    etc etc…
51

Wiring 1 will fry your thermostat. On terminal 1 you send 230V where it expects to output.
Wiring 2 will lead to powering off your thermostat when the boiler is turned off. HA will lose connection to the thermostat then, but you may want that ?
Send it back is the most secure thing if you can get the gas boiler version.
But this one can work with wiring 2 or like that :

Thermostat    Boiler
1             In 
2             -
3             -         N from electrical supply
4             -         L from electrical supply
52

Why would wiring 2 power off the thermostat?

Your one won’t work because the out has to be connected somewhere.

@cooljimy84 - can you confirm what the output voltage is on your pin 1 (L1) ?

53

Because Live input (terminal 4) gets power from the Out terminal of the boiler. It will turn off when you power off the boiler (like when going on holidays ?).

The “out” of the boiler lets you use any switch (even a manual one), so you don’t have to provide 230V to terminal 2 from an external source.
With this thermostat, terminal 1 will provide the 230V, don’t need to use the power brought by boiler. But, like I said yesterday, it might make the boiler go to a security mode.

54

Surely that Out terminal must be permanently live, otherwise how would it know that the switch was closed??

I do have to provide power from Out, it says so on the label - I presume if I don’t draw power from out and then return power to in when I was heating THAT’s what would cause a security mode problem??

55

Exactly ! But it seems it could work, see James’ wiring. You’ll have to try.
Just like the thermostat could do the same if power goes out of Live but doesn’t return to Neutral. Once again, James’s wiring tends to prove it doesn’t.
This is how a differential circuit breaker works : if power goes out, but doesn’t come back, it’s likely something (or someone !!) is linking the circuit to the earth…

56

OK - if @cooljimy84 can confirm that it’s 240v on the output from L1 with his wiring config I’ll try my ‘wiring 2’ and see what happens (from outside the house, obviously - don’t want to burn to death :wink: )

57

At the moment can’t can’t measure the voltage as my 2 and a half year old is being my shadow today and has wooden tools she likes to “help me” with…

Tho from logic I’m sure it’s 240 volts as the Danfoss wouldn’t take a 240 volt feed and then divide it down to 24? Would it?

58

Wowsers, I’ve mode a nodered ?flow? As making changes to HASS and rebooting every time is a bit much.

59

They’re so helpful :laughing:

Ok, I’m going to get some 3 core at the weekend and go with wiring 2 and see what happens :slight_smile:

60

I’ve tested those a lot. Reboot is a pain, but I try to keep everything native HA, avoiding middleware (MQTT…).
I used the developer tools/templates to evaluate different rules at once. Remember, I made this during the summer without the actual thermostat !

You could also go further and add input_number to change the weights. This makes calculations totally dynamic. 1 per sensor, 1 for the min, 1 for the max, and one that you calculate as the sum from the previous as a divider.

With the latest rules, my wife finds the temperature ‘real nice’. She’s cold when it’s below 20, and too warm when above 21, so I guess it’s a challenge :wink:

61

Slowly getting the hang of nodered, as I want overrides if any room drops below 22 (my wife likes a hot flat)

I’m also running another flow (is each tab a flow?) That has weekday and weekend temps, that I might then feed to HASS as at the mo it’s just a target temperature from an input slider.

Gosh this has got complex quick ! The wife wants a boost button, to just get the radiators warm to the touch !?!