Gaylord 18782 Thermostat

What the Thermostat Does

A thermostat acts as the switch for your temperature control system. It senses ambient heat and signals the equipment to turn on or shut off when the target setting is reached.

Most central systems operate on a 24 V control signal sent from a transformer. Baseboard heating setups typically use line voltage instead. Because line voltage and 24 V systems are not the same, you must confirm what your system requires before attempting a repair.

Understanding the Part Dimensions

Thermostats must fit their mounting location, housing, or bracket properly. Checking the exact outer measurements of the part ensures it can be installed without clearance issues.

• Height: 2.4 in / 6.10 cm
• Length: 22.55 in / 57.28 cm
• Width: 6.1 in / 15.49 cm

How to Confirm a Replacement Matches

Always compare the old unit directly to the new part specifications. Control systems rely on specific configurations to run correctly.

• System type: Verify your equipment type, such as gas, electric, or heat pump.
• Stages: Check how many heating and cooling stages your equipment uses.
• C wire: Confirm whether your setup requires a common wire (C wire) to provide continuous power.
• Voltage: Determine whether your system runs on 24 V or line voltage.

Signs of Failure and Safe Replacement Steps

A faulty thermostat may fail to call for heat, stop reading temperatures accurately, or lose power completely. When replacing the part, working carefully protects both you and the equipment control board.

1. Shut off electrical power to the equipment at the main circuit breaker or dedicated service switch.
2. Remove the cover or housing to expose the wiring connections.
3. Take a clear photo showing which wire attaches to which terminal letter.
4. Disconnect the wires carefully, keeping them from slipping back into the wall or enclosure.
5. Mount the replacement part and attach the wires one at a time to the matching terminals.
6. Restore electrical power at the breaker and test the system response.

Read your old part

1. Look at the label or stamp on your existing part to find the part number.
2. Check that the part number reads 18782.
3. Measure the old part to ensure it matches 2.4 in / 6.10 cm in height, 22.55 in / 57.28 cm in length, and 6.1 in / 15.49 cm in width.
4. Identify your system type, heating and cooling stages, and whether a C wire is present.