New Dual Fuel System Switch over problems

Old 11-01-19, 08:45 AM
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New Dual Fuel System Switch over problems

Brand new here, thanks in advance for any and all help,
I'm honestly at wits end here I've exhausted my knowledge and i still cant get the issue resolved.
Completely brand new system.
Trane 4twr6 3-Ton 16 seer Heat Pump
TUH1B080 XR-95 80K Gas Furnace. matched coil.
JCI T9100 stat.
Kele 10k ohm OA Temp sensor

18/8 wire with home runs from stat to CU, Stat to Furn,( it was easier to do it this way than through the furnace because of the length between the 3 devices so I made up the connections in the wall box behind the stat rather than in the furnace)
Everything runs fine in cooling and in heat pump mode. When I set the lock out temp on the stat and it reaches the lock out temp outside, the stat wont fire the gas furnace or the HP. I can manually make it use only gas by enabling the Emergency heat. Then it will run only gas heat in a traditional manor, but the reason I went this route is to not have to do that. I tried to avoid using the trane comfort controller but I'm starting to think that may be my only option. I just have a hard time believing that the dual fuel stat cant do this on its own.

Attached are the wiring diagrams i drew up. original and Rev 1.

Initially what I thought was the problem was the black on the HP was somehow confusing the stat and when it called for aux heat it was hitting the HP instead of the Gas. SO I reconfigured the CU and the connections at the stat to combine the signal from the reversing valve and the HP Black and landed the furnace call on W2 but that didn't work either.

I've got a pretty good working knowledge but I've reached my limit and need some help to figure this out.
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Old 11-01-19, 01:56 PM
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Welcome to the forums.

When looking thru the install manual I see wiring/settings for heat pump with backup heat.
I see no mention of dual fuel programming which makes me think that stat will not work for want you want it to do.

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