Marley Engineered Products 5813-2001-000 Thermostat While the barbed fittings are

While the barbed fittings are optimized for 1/4" OD polytubing

Johnson Controls F-1000-322 Anti Kink Spring

eliminating the need for complex field modifications during service calls

Use a multimeter to check for 120V at the primary leads

Marley Engineered Products 5813-2001-000 Thermostat While the barbed fittings areFor field technicians and contractors maintaining Q Mark or Berko heating units, the Marley Engineered Products 5813 2001 000 Thermostat serves as the direct OEM replacement for residential and commercial wall heaters. This mechanical snap action thermostat is engineered to handle line voltage applications without the need for additional relays or complex control boards. It features a single pole single throw (SPST) configuration, making it a rugged