Heat pumps are touted as a sustainable solution for home heating, but transitioning from traditional boiler systems can introduce significant challenges. In our case, the switch to a heat pump was far from seamless. Initially thought to be a moderately well-installed system, it turned out our ASHP was only about 60% effective. This discovery unfolded over years of trial and error, coupled with numerous conversation with professionals and with other homeowners on the Renewable Heating Hub Forums, highlighting a significant potential for improvement.

Realising the complexity of the issue, we engaged Ken Bone (@kenbone) from Ultimate Renewables. His thorough inspection revealed that our system was not only inefficient but also costly to operate. This scenario is not uncommon in homes where legacy heating systems may not be fully compatible or optimally configured for new technologies like air source heat pumps.

During a casual chat (see below) Ken discussed the nuances of our existing system's failures. Key issues included undersized piping that couldn’t handle the required output, leading to inefficient heating, especially noticeable at the far end of our house where radiators struggled to reach the desired temperature. Our system’s Coefficient of Performance (COP) was also underwhelming at 2.7.

Ken proposed several adjustments to enhance the system's performance – we'll be scheduling the work in, in due course. These included resizing and reallocating flow to balance the distribution between the underfloor heating and radiators. He also suggested revisiting the system’s buffer tank configuration to reduce heat loss and increase overall efficiency. His goal was to raise our COP from 2.7 to between 3.5 and 4.

The remediation involved not just technical adjustments but also a reevaluation of the control systems governing the heat pump and distribution network. Ken aimed to create a more 'open loop' system to decrease reliance on unnecessary pumps and valves that added complexity and cost. These changes promised not only to improve energy efficiency but also to enhance the comfort levels across different zones of our house.

This experience highlights a broader issue in renewable energy adoption: the necessity of proper design and installation. It underscores the importance of professional expertise, particularly when retrofitting modern systems like ASHPs into existing homes not originally designed for them.

Transitioning to renewable heating systems involves more than just replacing equipment; it requires a deep understanding of both the new technology and the existing home infrastructure. Our story is a poignant reminder of the value of getting the details right the first time around. For homeowners considering similar transitions, thorough professional assessments and interventions can significantly rectify initial inefficiencies, leading to better performance and greater satisfaction.