Tekmar 544 - No Display

Bucks1679

I am a homeowner trying to install a new Tekmar 544 thermostat. I am upgrading from a Maple Chase that is 10-15 yrs old. I found most of the literature I needed online for reconnection, but can't get a display on the new Tekmar. I have searched everywhere online to get troubleshooting for this issue with Tekmar thermostat, but there is none for this issue.

On the previous thermostat I had connections to W (Htg Control), Y (Clg Control), G1 (Fan Control), and RH - 24 V Power (which was jumpered to RC). On the new Tekmar, I connected the existing RH wire to R. And provided a connection from Rh1 to Rc per the wiring diagram. The compressor kicked on outside when I did this. I connected the existing W to W1. The existing Y to Y1, and the existing G1 to G1.

I still have no display. The compressor will start and run as long as Rh1 and Rc have a jumper connection. What am I missing? Any help with the display would help immensely as I am out of ideas. Do I have a faulty temperature sensor? Is there anything I can do except return it and try again?

Thanks!

-Buck

chief

tekmar 544 - no display

Sounds like you are missing the common wire for the 24 volt supply. This may require running a new wire to the stat. With not knowing what type of system you have I would recommend you call in a pro to handle this one.

Paul Fredricks_3

I agree

I haven't worked with these thermostats very much, but I'm fairly certain they need a 24v supply. I think a dedicated 24v supply is required on the R and C terminals. That powers the thermostat. The other terminals operate the equipment.