Heat pump manufacturer Stiebel Eltron has warned that leaked findings of an incomplete study into the effectiveness of heat pumps must be treated with the "utmost caution".

An incomplete Energy Saving Trust (EST) report has recently been leaked which suggests that the performance of heat pumps is "unreliable", but Stiebel Eltron's UK operations director, John Felgate, said that the heat pump industry was "determined to set the record straight".

The report was leaked against the wishes of its authors, who have said they are still unsure about the findings. Felgate described this action as "reckless and irresponsible", and said it could undermine plans to introduce the Renewable Heat Incentive next year.

"It is vital we do not allow this unhelpful leak of a half baked report to distort the truth about heat pumps," he said. "The EST has refused to comment on the leak, saying it has a responsibility to the industry and the public to be 100% sure that its data has been fully understood and cross referenced before being publicly released. So we must wait for the report to be rigorously tested and properly finished before jumping to conclusions. The RHI Is critical to the microgeneration industry and this ill-informed report must not derail it."

Mr Felgate said he understood 83 sites are being monitored in the study, which have to date produced wide-ranging performance results.

"These are still very early days in the UK for the microgeneration sector, which is why leaking this study before it is finished is so dangerous. This technology has been in successful use in Germany and France and elsewhere for many years and we need to treat this leak and talk of variable performance with the utmost caution."

Stiebel Eltron will undertake a free energy efficiency survey of any property in the UK to examine the heat demands of the building, before recommending which green technologies are most suited to the property, if at all.