Nest Thermostat installed on waste oil furnace and Power adapter wiring

[CJaco]

Hello,

I have a Clean Burn CB 2500 waste oil furnace in my shop and have recently purchased a Nest Thermostat. I have installed the thermostat and have the system working, but I do have a battery drain issue due to not having the nest power adapter installed.  I have the power adapter and I do not have an option for the C wire on my furnace. My Furnace is a 24v milli-amp system. I have 4 wires at my furnace where the thermostat wiring is. T1, T2, T3, & T4 the T3 & T4 wires go into the igniter and are hooked the the flame sense sensor.  I have the T1 (red) & T2 (white) hooked to the thermostat and the system will work but drains the batteries and doesn't stay online with Wi-Fi.  If I hook the power adapter up the thermostat says no power and the unit doesn't work because I do not have the C wire hooked to anything. Looking for suggestion's.  Does the C wire need 110v, 12v, or 24v?

[GabrielaG]

Hi CJaco,

Thanks for reaching out to the community. I'm sorry to hear your Nest Thermostat has a battery drain issue due to not having the Nest power adapter installed, but there's no need to worry; I'm happy to assist you right now.

I appreciate the information you provided me about your wires. It seems your system has high-voltage or stranded wires. A Nest thermostat may not be compatible with a system that has high voltage. The power adapter we use is the Nest Power Connector, which works like a substitution for the C wire, which usually needs 24V.

I recommend contacting a technician to check your wiring connection and advise you what is the best option for you.

Feel free to keep us posted if you have more questions.

Regards,

Gabriela

[Patrick_Caezza]

@CJaco 

You need the Google Nest Power connector and an external 24 vac transformer.

You would wire it like this,