ESP8266 Community Forum

My question is - how can I switch a water heater system from the ESP reliably?

Here is my experience so far:

I too have an ESP8266-01 connected to a Fotel SSR - the "SSR-40-DA".
Mr Scargill(.net) put me right on connecting the SSR to sink current from Vcc through the SSR to the GPIO pin - making it active LOW, as martinayotte says here.

So now the ESP8266 can turn the red indicator within the SSR unit on and off, but that doesn't switch the mains on and off like I expected. The SSR spec says between 3 and 32 volts to switch, and specifies 12mA. At 3.3 volts, it is drawing only 4mA, but anyway, the LED comes on. The SRR will turn a CFL on, though it flickers. It will not turn a conventional incandescent lamp on, which suggests to me that it is a the very margin of switching on.

If I tweak up the supply voltage to the ESP, I find it will light even an incandescent lamp solidly at 3.38 volts. However, the board stopped working shortly afterwards - it now sinks current at the limit of my power supply setting and doesn't work. I am supposing the tiny voltage increase blew it, though this seems unlikely.

So again, how can I reliably switch a UK mains water heater on and off with an ESP?

Any help is appreciated.

Chris

Maybe your SSR is defective.
Try to use it offline from ESP, trying the same specs of 3.3V and measure the sink current of the LED.
Is the load working right or you still seeing flickers ?

My question is : what is the input voltage srr relay for ESP8266?

My question is : what is the input voltage srr relay for ESP8266?