I was recently told by a well known maker of whole house fans that using Z-Wave wall Switches would void the warranty of their products. The product in question is this.
In the description it says the following.
Hardwired for power and control (control not included), recommended controls are the TTi-HVRC remote kit or an SPST wall switch or a non-digital spring wound mechanical timer, all other controls will void the product warranty
Any thoughts on why?