12-09-2022 08:36 AM
Hello! I installed two nest learning thermostats to replace honeywell switch thermostat. Heat only propane water baseboard system. So I have red and White wires connected to Nest Rh and W only.
The nest thermostats work but intermittently have power failure (e74 wiring error). I *think* need to connect up a nest power connector, but I am confused about how to properly do this with the Taco 404 controller relay board. There are no "R", "W" or "C" labels on the board. the thermostat switch lands on "T" lugs.
I tried to wire in the nest power connector with the R&W wires in-line as normal, but I'm confused on whethere to land the C wire of hte nest power connnector. Tried with C wire to the left as well as to the right lug of 24 V power terminal, but neither seems to work. The zone LED lights up "dim" when demanding heat.
12-13-2022 11:30 AM
Thanks for reaching out ― let's see what's going on.
Give these steps a try:
Keep us posted.
12-13-2022 11:52 AM
I have no air filter. System is hot water boiler with baseboard radiators.
12-14-2022 09:55 AM
I'm sorry to hear that you're still having an issue with your Nest Learning Thermostat. We'd like to take a deeper look into this — could you fill out this form and let us know once you're done?
12-17-2022 02:54 PM
@JohnHutchinson I wanted to follow up and see if you were able to fill out the form? Let me know if you have additional questions.
Thanks for lending a hand, Mel.
12-17-2022 06:35 PM
Hi , I have been away from home for past several days. I need more time to respond. I should be able to respond by end of the day 18th. Thank you.
12-18-2022 09:32 AM
No pressure! Please keep us posted once you're done filling out the form so we can assist you right away.
12-21-2022 10:10 AM
I'm checking back in — how's it going? Have you had a chance to fill out the form? Please let me know if you are still having any trouble from here.
12-26-2022 01:34 PM
@JohnHutchinson just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.
I appreciate the help, Mark.