For reliable heat pump protection, 2 valves must be installed – one on the flow pipe and one on the return pipe, as close to the pump as possible. This is because it cannot be determined with certainty in advance which branch of the system will cool down more quickly, as this is influenced by a number of factors including ambient conditions.

No. The valve contains a thermostatic sensor that must respond to the actual temperature of the medium. If it were insulated, water in another, less insulated part of the system (for example in the pump heat exchanger) could freeze before the valve has time to respond.

Not always – the valve works correctly even without it. However, in non-standard configurations, for example with some plate heat exchangers, an automatic filling valve helps maintain water circulation throughout the entire heat exchanger and protects the pump even during a prolonged power outage.

Yes. The valve is full-bore and generates very low pressure loss, so even when connected via a reducer to pipework of a different diameter, the increase in pressure loss in the system remains negligible.

Freezing occurs if the electrical power supply fails and the household does not have a backup power source (for example a generator). A monobloc heat pump without frost protection can then freeze at low temperatures – under normal power supply it can cope with the cold on its own.