Connect Nest Learning Thermostat: 3rd Gen with Lennox SLP98UH

This post covers the steps I took to setup my Nest 3rd Generation Thermostat with my Lennox SLP98UH or SLP98UHV furnace. My furnace was originally connect to the Lennox iComfort 1st Gen Thermostat.

Overview of Steps:

1.     Turn the AC & Furnace off at the circuit breaker.
2.     Take the furnace cover off.
3.     Unscrew the 2 screws holding the circuit cover on.
4.     Re-wire the wires from iComfort to standard R, Y1, W1, and G.
5.     Setup the Nest Thermostat.

Step 1-3 are simple so I'll start with details for Step 4

Step 4 Details

At my furnace the 4 wires connected to a special terminal designed for integration with the iComfort thermostat:

I took the Red, Green, Blue, and White wires and re-wired them to the appropriate terminals: Red -> R (Power), Blue -> Y1 (Cool), White -> W1 (Heat), Green ->  G (Fan) as shown below:

Step 5 Details
At my current thermostat I had the 4 wires: Red->R, Green->i+, Blue->i-, White->C:

To hook up those wires to the Nest, I used the stickers to mark the wires: Red wire -> Rh, White wire -> W1, Green wire -> G, Blue wire -> Y1. Then I hooked those wires up to the nest back bracket:

Then I put the thermostat on. After I turned the power back on at the breaker for Furnace and A/C, I entered my WiFi information (I chose my 2.4 GHz signal). The Nest downloaded a firmware update and then I completed the setup steps displayed on the Nest.

Here's the final picture of the thermostat installed!

I hope this post helps someone else setup their Nest thermostat quickly! !-- Scripts Start -->

Tweet

Lennox AC Repair

Our A/C Unit
Manufacturer: Lennox
Model Number: HS24-411-1P
Serial Number: 5192J05211

Our A/C stopped working. They system said it was cooling and the A/C unit was running outside but no cool air was coming out of vents.

We should've shut the A/C unit off immediately as it could have damaged its parts by running without cooling but luckily it did not damage its parts other than the part that was broke.

The capacitor broke and we paid $300 to have it fixed. It's a 1992 furnace but $300 is much cheaper than $5,000. If the repair was $1,000 or more, I may have been forced to buy an entirely new unit.

We purchased our house in 2010 and have had no issues with this A/C unit until now. I wanted to post this to let people know that an 18 year old unit in 2010 lasted another 6 years without a single repair and this repair was only $300 performed by Golden Rule!!

Image of AC Unit Label:

!-- Scripts Start -->

Tweet