... valve.6 Careful protections like high/low pressure protection, water flow switch protection, overheating protection, overload protection and so on.7 Fault self-checking ... , Sanyo, Daikin optionalQuantitypcs1Security functions Built-in overheating protection, phase order protection, under-voltage protection and time delay protection.Air source heat exchangerType Finned heat exchangerQuantitypcs1Fan ...