ESP8266 Community Forum

Hi,

I'm just getting started with home automation and successfully wired up my pool pump and downstairs HVAC. For the upstairs HVAC I followed basically the exactly same process as I did with my downstairs one (buck converter as supply, 8266 using tasmotize, 3 relays and a temp sensor). The supply is dialed in to 5V but when I plug it in I can't connect to the esp8266 via wifi (offline) and 2 out of my 3 relays switch on even though the state is stored to off. One of the devices makes some noise, can't really tell which one it is as the issue disappears once I change anything (which renders my setup useless, so that's not a solution ).
If I disconnect the relay input's of the 2 relays the esp8266 comes online, if I then connect the relay's everything works just fine.
Would really appreciate any tips anyone might have, not really sure what I can do to fix this.

Hi, I think a simple restart of the device might fix the issue.

Thanks for the response, I initially used Pin 1-4 but found some people having issues with certain pins. After moving Pin 3-4 to 7-8 everything worked just fine.

If your initial config using pins 1-4 held D4 (GPIO2) at a LOW level that would prevent a normal boot. There are several other "gotchas" like this. I recommend the very helpful summary and guide at https://randomnerdtutorials.com/esp8266-pinout-reference-gpios/