As stated in our tech Bulletin #15 dated April 3, 2007 , the Honeywell T87N1000 and the T87K1007 are not backward compatible with all Carlin primary controls already existing in the field. To wire these thermostats directly to a Carlin primary control such as on a warm air or steam system, follow the instructions on Tech Bulletin #15.

Polarity is not an issue and the T87 Mercury Free thermostat will work fine

40200 / 42230
Are not compatible and the T87 Mercury Free thermostat should not be used with this control, unless the Honeywell wiring instructions are followed

50200 / 60200 / 60200FR
Note: On these controls the label does not differentiate between T1 & T2. The T terminal on the left is T1 and the T terminal on the right adjacent to the F terminal is T2.

“R” must be wired to T1
“W” must be wired to T2

In our effort to help stop further confusion in the field we have also tested the TH1110D (Pro 1000), TH5110 (Pro 5000), and the TH610D Pro (Pro 6000). These thermostats will function with the 48245,40200,50200,60200 and the 60200FR as long as the battery backup is intact.  

The T8775C functions with the 60200 and 60200FR as long as the Red/White wire is constantly powered. The T8775C will function with the 48245, 40200, 42230, and the 50200 as long as the Honeywell wiring instructions are followed.  

For any questions, please refer to our Technical Support Hotline at 800-989-2275.