WIFI Switches/ Retrofit or Standalone Sockets

Can anybody recommend a WIFI switch that is compatible with HA and supports turning on/off Boiler system ( would require higher Amps guess 10A is fine ) . Looked at sonoff module but I dont think the module fits behind the socket . I dont mind changing the whole socket if there is good cheap product that works well with HA . I ordered though the sonoff Wall socket ( 2A ) module that is neat to install but i guess this will tolerate only lighting on/off I guess. I hope it will work with HA …I guess it needs soldering and flashing


By “boiler”, are you referring to an electric kettle or your water heater?

Hi Am reffering to the HVAC system of the house . heating delivered thru radiators in every room .

Well, I’m no expert, that’s for sure, and I don’t know how your current system is wired, but I’m going to assume that this boiler draws a significant amount of power (most probably over 10A) and should have its own line in the main power electrical panel of the house. If that’s the case, then my approach would be to get a simple Sonoff basic and connect that to a contactor and from that power the boiler. The sonoff should be flashed with the Tasmota firmware, which adds MQTT support to it and works fine with HA. I have a similar setup for my water heater (which can draw up to 4KW) and it works just fine.

Thanks for your reply. Actually the whole system is currently controlled from one button (on/off) switch with a rating of 10Amps regular switch. Its just a matter of sending an on/off command to close the circuit in order to turn on the main system which is located in the main building… since the sonoff basic is a bit big to fit behind a socket. I guess i will need to install it inside the main breaker panel.

Again, I may very well be talking nonsense here, but my guess is that this button switch is probably driving some sort of contactor in the breaker panel, rather than the actual load directly. I’d find it weird if 10A were passing through that button.

I will have to check . One question though . Does this sonoff switches provide their status ? i.e would i know on HA if actually the device is on or off . like if someone turned it off manually . I would have this updated on the app. I believe zwave switches do report their status am not sure about this one though. Thanks

An average single bathroom water heater is rated 1200W, in europe at 220VAC is about 5.5A. In theory it is well under the rating of the standard Sonoff, and less than one third of rating of the Sonoff Pow.

It should be a purely resistive load, so you should’n have to worry about power spikes (like the one generated for example by a water pump).

With smart switches I only have experience with sonoff flashed with Tasmota, I can’t give any advice other than I have 5 installed (standard, pow, plug, 4ch) and I’ve had no problems until today.

Thanks did you install while keeping the manual switches for manual intervention . If so , does it report its status if someone manually switched on/off the button ?

Yes, they do. If someone press the push button on the sonoff, it will be reflected in HA.

My boiler (UK Bosch Worcester).

I have a relay running on a ESP8266, 12V/240V MAx 10A load, which is actually standard in most sonoff devices. I removed my thermostat and put the relay in its place. Now i can leave my boiler switched on, and it will run when the relay is fired via HA/MQTT. All my rads have manual thermostat.

Works well for my needs. I put it on when its needed and off when i dont, and you could set automation/timer in HA if required.

Thank you guys for the feedback . I think I will give the sonoff basic a try with my needs. Does anybody have a link for the full flashing procedures to have this work with HA ? I looked at https://github.com/arendst/Sonoff-Tasmota but i cant see where is the actual step by step proc.

If you’re going to the Sonoff route, I suggest you to get the Sonoff Pow. For 4 euros difference you get a better power relay (16A instead of 10A) and the power monitoring capability, so you can check the real power consumption or check if and when water reached the preset temperature.

Any chance of a picture of how you wired it up? I have the same boiler and a sonoff on the way and plan to attempt the same.

I have just ordered them ill update you how i proceed forward when i get them

in the wiki https://github.com/arendst/Sonoff-Tasmota/wiki there are all the instructions for flashing with a programmer.

Another way is over WiFi with SonOTA https://github.com/arendst/Sonoff-Tasmota/wiki/SonOTA---Espressif2Arduino---Tasmota-without-compiling . I never tried it, but read in this forum people that made this way successfully.

Its just a case of the 2 wires that go to your thermostat (should be labelled on the boiler terminals) you put these two wires accross common and normally open (NO) on the relay. then program accordingly.

When the relay is activated via HA it will go closed and make the circuit, which will fire up the boiler, if the physical switch on the boiler is set to 1

Hi, the sonoff basic does not expose a common and normally open contacts. It exposes neutral and live. So it acts as a switched power outlet rather than a switch or relay. So be careful about how you will connect it to your boiler.

Good point lexam79. I’m using the linksprite 8ch and 4ch Relay boards with esp easy on

Amazon uk did sell them but now can only be bought from linksprite direct.

Hi Lexam , Can you please elaborate more on this point . What do you mean by this limitation . Thanks