Review on Honeywell THP9045A1023 Wiresaver Thermostat Wiring Module by Dwayne Calhoun

Old house (circa 1989) with a 4-wire thermostat in the wall (no C-wire). Therefore, most WiFi thermostats require a bypass. If you make a decision in the thermostat, you will lose the low speed fan function. So you need C-Wire or this wiring module. It was a bit difficult for my oven to find a mounting position that didn't require intrusion into the combustion chamber or the outside of the case, and still leave enough room for cable routing. We ended up using an old window frame bracket and an old metal plate from the underside of an old sliding door to make a bracket for this module. There are probably easier ways. After connecting everything is fine. I love the solution although I wish it was less expensive. I especially liked that there were no cables to run through the walls (it's still impossible on the second floor)!