Emerson 90 380 Fan Relay 24 Volt Coil, 1

This switching relay works well with Wi-Fi thermostat

No issues. Simple replacement or use to augment your HVAC system. This is a quality part, not a cheap knockoff. You don't want to risk anything effing up your HVAC controls because they will fail at the worst possible time, guaranteed.

Works great. I measured the current draw of the coil it is only 320ma. Was worried because using my new furnace to control a humidifier and didn't want to much load. But 320ma is very low. I am turning on a small fan and solenoid of the humidifier with the contacts. Works great and my home is no longer dry.

Update - December 2022:This relay worked reliably for roughly 3.5 heating seasons. Recently, there were two separate instances where it would audibly click when my thermostat came on but the boiler side wasn’t being connected. I tested the boiler wiring directly and it fired up immediately.Since the relay appeared to be the most likely culprit, I replaced it with a spare one I had which immediately worked as expected.I’m satisfied for how long it lasted. I would recommend buying 2 at a time to just always have a spare if you’re ever using it for something like a Nest.The original seemed to fail when the heat was cycling more than usual as well. Guessing it sped up what was inevitable.Otherwise, my original rating still applies. These are simple and easy to use with a pretty decent lifespan.——————Original Review - October 2019This little relay is cheap but quality. I got this to use in tandem with a 24v hardwired transformer to control my millivolt boiler. Since my current system had no C wire and was just the Rh/W wires to turn the heat on, I couldn't just plug in my Nest.After some research, it seemed like the safest way to add a 24v power supply would be to use a transformer and a relay. Some tutorials claim plugging in the two transformer wires into the C and Rc ports on the Nest will get it to work (which it will) but you run the risk of the Nest sending the 24V of power down to your millivolt system which would not be good.To get around that, I wired up my transformer then ran the Rh wire to the thermostat and the W wire from the thermostat to this relay on the control end then back to the transformer to complete the circuit. Then just plugged in the Red and White wires coming from my boiler into the controlled side of the relay. Completely eliminated the possibility of the two different voltages crossing and messing anything up on my ancient heating system. I also ran an additional wire for the C and Rc ports to provide continuous power but that's not necessary in this setup, just peace of mind for me.Now that it's been getting cold, this relay has been tested without a problem. The Nest kicks on to call for heat and the relay gives a reliable click with the heat kicking on immediately.Just keep in mind this is a physical relay so the click is going to pretty audible. If you don't want to hear it, put it somewhere tucked away. If you're not a fan, you can find a solid state relay that should do the same thing.

Did its job, connecting Nest thermostat to my Lennox furnace to make it run properly, GOOGLE and LENNOX should get together to correct this “PROBLEM”, and quit BANGING HEADS