Johnson Controls A11B-1 Thermostat & Controllers Freeze Protection Open-Low 35°F 45°F 20'Capillary

The Johnson Controls A11B-1 is a mechanical low-limit control to protect HVAC systems from freezing. Instead, it employs a vapor-charged bulb that changes its size in response to changes in heat. If the temperature drops outside the given range of 35°F to 45°F the switch SPST breaks isolating power to the cooling system and therefore stops the cooling operation. This is especially useful in minimizing chances of coils and pipes freezing over time leading to build-up of pressure. The A11B-1 is made for durability, steel built and small measuring 0.6” in size, ideal for small areas.