Greenhouse Line Voltage Thermostat Thermostats Automate GreenhousesAutomate your greenhouse heating and cooling systems with our quality manual Greenhouse Line Voltage Thermostats including wired and plug-in thermostats.

During the cold winter months it can be a struggle to maintain temperatures in  your greenhouse or growing structure.  Using our durable manual thermostat controllers, installation and execution to regulate warmth is simple!

The manual thermostat controllers make it easy for you to control the temperature to match your greenhouse needs if you’re choosing to use an electric heater.

Additionally the thermostat has an automatic shutoff to prevent overheating to keep your plants protected from cold and hot temperatures! By adding an electric heater with a thermostat controller, you can enjoy growing all year long!

Selecting the right Greenhouse line voltage thermostat, locating it to sense plant temperature and maintaining the thermostat can save considerable fuel and electricity.


When selecting a thermostat for use in the greenhouse, look for the following:

  • Moisture and dust-tight boxes
  • Capillary tube filled with a liquid or gas that expands to activate the switch

Click here to see our greenhouse line voltage thermostat product catalog.


Proper installation can also have an effect on thermostat operation. The thermostat must feel the air that the plants feel if you want to control the temperature in the plant zone.

The best locations are:

  • At plant height near the center of the greenhouse
  • Mounted on an end wall or sidewall of the green house
  • Not directly above heat pipes or in the direct line of a heating duct outlet
  • Shade the thermostat so it is out of direct sunlight

Once the thermostat has been located in your greenhouse, setup to your heater is simple!

If purchasing a thermostat with piggyback plug, like this one, then follow these instructions:

  • Plug the heater power cord into the thermostat plug
  • Adjust the thermostat dial to the desired temperature (60°F) when you want the thermostat to turn on the heater. Please note the Tempro thermostat will auto shutoff your heater once temperature rises 3°.

If without a piggyback plug, like this one, then follow these instructions:

  • Wire the thermostat directly to the heater
  • Adjust the thermostat dial to the desired temperature (60°F) when you want the thermostat to turn on the heater. Please note the Tempro thermostat will auto shutoff your heater once temperature rises 3°.

Click here to see the complete instruction manual.


All thermostats should be checked for accuracy at least once a year. They can get out of calibration due to dust and dirt on the sensor.

  • Clean the sensor with a can of compressed air and wipe if there is still dirt on it.
  • Set the dial to below room temperature for 10 minutes.
  • Slowly raise the dial setting until it just makes contact.
  • Check this against an accurate wall or digital thermometer. If there is a difference, mark it and have the service person make adjustments the next time the furnace is serviced.

Slash energy costs and receive the maximum benefits year round inside your greenhouse by using Tempro thermostats.

Talk to a product specialist today!

Thermostats & Guards

Tempro offers line voltage thermostats & guards commonly found in commercial, industrial and agricultural settings.

Custom Options

Variety of custom options available in both thermostats & guards, such as, temperature ranges, materials, size & private branding.


Tempro products meet NEMA, UL, cUL & NEC 457 Ag-ratings.

High Quality

We take pride in quality control & reliable operation of our components. Every switch is individually tested before it leaves the plant.

Stocked in the U.S.A.

Products are designed & shipped from our facilities in Eau Claire, WI to clients across the globe.