THM5421R compatible with Nest 4th gen

[prashanth149]

I have THM5421R EIM module in my Garage and tried replacing just the thermostat inside and does not turn on the Heater. 

Question is if I have to replace my thermostat to Nest do I need to rewire or replace the EIM module? 

[CoolingWizard]

@prashanth149 ,

The Honeywell THM54214 EIM is a very special device designed to allow very sophisticated programmable Honeywell thermostats to work with advanced HVAC equipment that does not have enough conductor wires between the two ends for the thermostat to control the equipment.  

The EIM uses a digital communication interface, which is not compatible with any other thermostats. If you wish to use a Google Nest thermostat you’re going to have to rewire your equipment. You’re going to need to present a thermostat cable at your thermostat location, which has five conductors and best to have seven conductor wires inside.

When you look at your thermostat cable that’s currently inside your thermostat location. How many conductor wires are inside the thermostat cable?

If the information I have provided, helps you to understand the problem, tap the kudos thumb below. If the information provided solved your problem why not tap the recommend the answer below. 

AC Cooling Wizard

[prashanth149]

Thermostat inside the houseEIM module in the Garage

Thank you for the reply I really appreciate your feedback. 

These are the wires I have in the EIM module and also the thermostat inside the house.. Is there a easy way to bypass the EIM module and make the Nest Work?