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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 5648
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I am installing a new Trane 950 Tstat and am receive Alert

Customer Question

I am installing a new Trane 950 Tstat and am receive Alert code err 91.06
JA: I'll do all I can to help. How long have you been dealing with this?
Customer: 10 minutes
JA: Do you plan on doing the work yourself?
Customer: Depends on what we have to do
JA: Anything else we should know to help you best?
Customer: No, I am just upgrading my Tstat from a regular communicating unit to a wireless communicating unit
JA: Did you double-check the thermostat? And what about the unit's filters?
Customer: It's a brand new Tstat
Submitted: 2 months ago.
Category: HVAC
Customer: replied 2 months ago.
Customer: replied 2 months ago.
I have found the issue with err91.06, but now the unit will not detect the IDU or ODU.
Expert:  BillyHvac replied 2 months ago.

I apologize for the wait.

Turn off both indoor and outdoor unit at the breakers. Wait 5 min.

Turn on outdoor breaker and then indoor breaker.

Tell me if it locates after 5 min

Customer: replied 2 months ago.
Ok, I 'll try that.
Expert:  BillyHvac replied 2 months ago.

just reply when you have info

Customer: replied 2 months ago.
In the mean time, the old communication unit had 4 wires S1, S2, B, R. The new unit shows a spot for 3 wires B, R, D. S1 and S2 are Data on the old one and D is data on the new one.......
Customer: replied 2 months ago.
The old unit is a ZUSTATALMS10 and he new unit is a XL950......
Expert:  BillyHvac replied 2 months ago.

s1 and s2 are used for remote sensor. Do you have wires (or did) on s1 and 2 and if so where is the remote sensor?

Customer: replied 2 months ago.
S1 and S2 are labeled as Data. There are 2 empty slots for RS1 Ad RS2 for the remote sensors.
Expert:  BillyHvac replied 2 months ago.

the yellow and white. What terminals do they attach to in blower unit and tell me terminals avail in blower or supply model number

Customer: replied 2 months ago.
This is a Trane Comfortlink Zoning system. There are multiple dampers on the system a main Tstat and a minor Tstat. Both Tstats are hook up to the same terminals on TB1 (top left).
Expert:  BillyHvac replied 2 months ago.

If the 2 thermostats are hooked to the same terminals how do the dampers work independently? I normally see one thermostat per damper....

Customer: replied 2 months ago.
Close up
Customer: replied 2 months ago.
There are 2 cards in the circuit board (Plus some empty slots) that are for the dampers, but only one
spot to install the Tstats.
Customer: replied 2 months ago.
The 5 minute system off did not make a difference.
Customer: replied 2 months ago.
This is the current system
Customer: replied 2 months ago.
New Tstat wiring
Customer: replied 2 months ago.
As you have not been able to resolve my issue, I have contacted a company to make a service call. Please refund my money.