Why is there no power to my RH wire?


Quote from Youtube video: I've had this happen a couple times now. And it's caused by the float switch on the air handler detecting that the condensation.

Why does my Nest say no power to R wire?

When there is no power to the R-wire on your Nest thermostat, start by checking the wire itself. What is this? You should also make sure your drain pan isn’t clogged and that your float switch hasn’t been tripped.

Why is there no power to my Nest thermostat?





Nest Thermostat. If your Nest Thermostat won’t turn on, the batteries could have drained or there could be a power issue. If there’s a power issue, your thermostat’s battery will drain and it’ll turn off Wi-Fi, the display, and other features to preserve battery life.

Does R wire go to RC or RH on Nest?

An R wire can go into a Nest Learning Thermostat’s Rc or Rh connector. The Nest Thermostat E only has an R connector, which is typically where an R wire would go.

Where does Rh wire go on Nest thermostat?

Note: If you have an R, Rc or Rh wire, you can put it into the R connector on the Nest Thermostat. If you have a W2, Y2 or O/B wire, you can put it into the *O/B connector, if needed. Gently tug each wire to check they’re secure, and make sure each connector that has a wire stays down.

What is the Rh wire for?

The Rh wire connects to your heating system as opposed to your cooling system. This wire may be red without an “H” attached to it, depending on if you have a dual transformer setup. The Rh wire connects to the RH terminal on your thermostat.

What is the Rh wire on thermostat?





The Rh wire connects to your heating system as opposed to your cooling system. This wire may be red without an H attached to it, depending on if you have a dual transformer setup. The Rh wire connects to the RH terminal on your thermostat.

How do I fix no power to Rc wire?

The E73 error on your Nest thermostat indicates that there is no power detected to the Rc wire. To fix this error, check your wiring, air filter, drain tubes/drip pans, and HVAC fuse and ensure that all of them are working correctly.

Should RC and RH be connected?

If you have both an Rh (Red-heat for powering the heating) and an Rc (Red-cool for powering the cooling), then the R wire can be connected to either Rh or Rc. If you only have a single R wire, then it will only have an R connector, which is the connection you’ll use.

Do I need a jumper between RH and RC?

In most cases, the heating and cooling system share a single transformer by leaving the jumper in the lower right corner it connects the RC and RH to power heat and cool features. The only time this jumper would be removed is if the heating and cooling systems have their own transformer.

Is Rh wire same as R?



R , Rh , and Rc are all the same, but not. In general terms, the R terminal is where you connect the signal voltage source. In low voltage controlled systems, there will be a step down transformer that provides the power to the control circuitry.

What is E74 error on Nest?

Nest states that this error code (E74 or N72) occurs when no power is supplied to the RH wire. However, understanding why an issue is transpiring does not necessarily tell you how you can resolve it.