What are the advantages of a ground source heat pump?

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ID: RE02e

It has a lower CO2emission than an equivalent oil boiler.
A heat pump running on ´green` electricity qualifies as 80% renewable and as a zero-carbon heat source.
Ground source heat pumps need maintenance.
A heat pump can use much less energy than a typical heating system to provide the same benefit.
Ground source heat pumps are low-noise solutions with a 20 year life expectation.
Ground source heat pumps have to follow the safety and regulatory obligations of gas appliances.