Broke older style mercury thermostat - can I get a replacement? Trol-a-temp

richtj99 · 09-13-2012, 03:16 PM

Hi,

I have an older Honeywell trol-a-temp thermostat which I managed to break. I am posting images of my items, but can I just replace it with a digital thermostat? If not, can I buy something off of ebay or somewhere else that might work?

Mastertrol Mark V, 2 zones.

If i put two of the wires together, I can get it to turn the heat on, the other two wires will turn the air conditioning on. There are a total of 3 wires for this.

The way the setup works, is I have the master control of heat, fan, or A/C in an office, the thermostats are all set on their own, when i turn on the master control to one of the three selections, the heat/a/c goes on & the thermostat will stop calling when ti gets to the temperature.

Is there some way for me to make this work with a three wire thermostat?

Thanks,
Rich

hvactech126 · 09-14-2012, 07:17 AM

you need a thermostat capable of a series 20 operation. Do you want a mechanical stat again, or a digital? You can do a google search for series 20 thermostat and get many options.