IMPROVED RELIABILITY OF SWEDISH RESIDENTIAL HEAT PUMP SYSTEMS
This paper describes a study of the most common failures of residential heat pumps in Sweden, with the aim of suggesting what measures could be taken to reduce the number of failures. Methods used were analysis of public failure statistics and interviews with installers, service technicians, manufacturers, sales agents and claims adjusters at insurance companies. Based on answers given in the interviews and analysis of the statistics, the aim was to categorise the most common failures by whether they; • could have been prevented by better operation and maintenance • were caused by poor installation work quality • could have been prevented if certain parameters had been measured, recorded and followed up • were due to poor quality of components or systems. The results showed that many of the common failures fall into several different categories, and that different types of measures must be taken to improve the reliability further. The interviews showed that failures are probably often caused by poor installation, neglected maintenance and surveillance, and/or poor quality of standard components or use of components outside their declared operating range.