Hello,

I have tried installing two HS210 switches to replace two "dumb" 3-way switches controlling the same ceiling light. As per the subject the HS210's start rapidly switching on and off as soon as power is applied on the circuit breaker.

I have read in another thread that this may indicate contact issues with the neutral wire, but I've double checked them and all contacts seem firmly connected.

I understand certain types of 3-way switch circuit wiring may be incompatible with smart switches and may require a circuit change; is this the case here?

Would anyone have any suggestion for me to troubleshoot/fix this?

Below is the wiring on my old 3-way switches. I have labeled the wires as instructed in the HS210 install manual.

3-way switch closer to the circuit breaker:

3-way switch closer to the ceiling light:

Any help would be greatly appreciated.
 

Thanks,

Guillaume