Posts Tagged ‘ Volt ’

• Easy Do-It-Yourself Installation (Installs in 30 Minutes or Less)No Leveling Required to Install Thermostat for Accurate Performance
• Environmentally Friendly Mercury-Free Design
• Includes Optional Wall Plate to Cover Hole Left by Virtually All Thermostats
• Easy to See Adjustment Scale for Better Readability
• Large, Easy to Hold Switches and Adjustment Lever for Easier Use

Product Description
Thermostat, Single Stage low Voltage Mechanical, Square, Heat OnlyCompatible with Most Furnaces & Cooling Systems (24 volt & milli volt)… More >>

Hunter 40020 Single Stage Low Volt Heat Only Thermostat

Have moved into a house where previous owner replaced simple mechanical type thermostat (with mercury bulb) with an electronic unit. Mechanical type obviously just closes a contact to complete the gas valve circuit and so get 24V across gas valve coil.
Obviously 2 wire electronic unit cannot do this because the unit needs to draw power for the electronics.
The new thermostat is giving unreliable operation, am thinking of replacing it with the old unit which I found and appears to be functional (checked with multimeter).