I wanted to install a progammable thermostat to my oil fired furnace with air and was told that I would have to insall a relay on my furnace. Where do I install the relay and how?

23344 wireing diagram for a Thermo Pride furnace. The thermostat I was going to install is a Hunter but missplaced it for nowl

Somebody' pulling your leg. You need a conventional fuel (oil/gas) thermostat, preferably non-Hunter. "C" may be required for a non-battery powered stat.

G is used for fan control and for Air Conditioning
Y is used for air conditioning

It is already in the diagram. The item that activates the fan is called the Fan Center Relay. The G terminal/Green wire on the thermostat activates the Fan Center in the cooling mode to activate the blower motor. Looks like you are all set to go to work.

Keepitsimple here is his original post

https://www.askmehelpdesk.com/heating-air-conditioning/installing-progammable-thermostat-relay-385738.html