HVAC thermostat wiring help

[Deplorable]

I have a heat pump with a gas furnace. Heat pump runs unless it gets below a preset temperature outside. This is set by a temp module outside in outdoor unit. It’s worked perfect for 16 years.

I’m trying to replace my archaic White Rogers thermostat with a Honeywell RTH9585WF.

My old thermostat had a jumper from E to W1. I have no idea if this is necessary for new one.

Do I need a jumper for new thermostat? It looks like this...

And lastly, if it’s necessary, here’s what the wiring at the air handler looks like...

 

[braxton357]

It's wired that way so that when you choose emergency heat on the thermostat it kicks on the gas furnace.

 

[paradisePWoffrd]

Most of these WIFI units can be programmed as dual fuel, and eliminate the current outdoor thermostat. It will kick on the furnace based on programming within and outdoor temp from the internet.

 

[willness33]

It's wired that way so that when you choose emergency heat on the thermostat it kicks on the gas furnace.

Will it also run the gas during the defrost cycle? Just wanting to learn something.

 

[braxton357]

Will it also run the gas during the defrost cycle? Just wanting to learn something.

Yes. But If the outside stat is set fairly high, it might not go into defrost very often or at all.

 

[Deplorable]

Thanks for insight, unfortunately new thermostat is inferior to 16 year old Tstat that can do everything I want!