Klixon® 204 Series Thermostats are fixed-setting, snap-action temperature limiting/fan controls used in appliances, heating equipment, and industrial or commercial apparatus. Automatic reset devices are available in single-pole, singlethrow (SPST) or single-pole, doublethrow (SPDT) configurations. Manual reset devices are available in SPST only. The Klixon snap-action bimetal thermal disc may be enclosed or exposed. Exposed types have a faster thermal response.

The 204 Series Thermostats are supplied in three basic contact constructions, as identified below: The letter “F” added to the series number, i,e, 20400F, indicates that the thermostat is supplied as a fan switch for applications such as forced air heating systems, where normally open contacts are required to close on temperature rise.
The letter “L” indicates that the thermostat is applied as a limit control or a high limit safety, with normally closed contacts that open on temperature rise. The letter “D” indicates SPDT switching action, which combines the “F” and “L” functions.

The 204 Thermostat can be mounted in any position -- in casting wells, through openings in metal enclosures, or in open space for control of air temperature.
A 204 thermostat with a “bottom flange” is used for surface mounting applications. A “top flange” is used for airstream or thruhole mounting requirements.

Key Features

• The 204 Thermostat can be mounted in any position
• Construction is varied to suit specific needs
• CThe Klixon snap-action bimetal thermal disc may be enclosed or exposed