Overview
As part of a full property renovation, the homeowner appointed Henman Dunn to replace an ageing electric storage heating system with a modern, energy-efficient air source heat pump solution.
The property had no mains gas connection, making it an ideal candidate for low-carbon heating technology. The homeowner’s key priorities were simple: a heating system that was easy to operate, highly efficient and as quiet as possible in day-to-day use.
Why a Heat Pump?
With no mains gas available, an air source heat pump offered the most efficient path to low-carbon heating — eligible for the £7,500 Boiler Upgrade Scheme grant and capable of significant reductions in both running costs and carbon emissions.
Following a detailed room-by-room heat loss assessment, our team designed a bespoke heating solution and presented the customer with three leading heat pump options. We took the time to explain the advantages, considerations and control systems associated with each manufacturer, helping the customer make an informed decision based on their individual requirements.
Following our recommendation, the customer selected a Vaillant aroTHERM 5kW Air Source Heat Pump paired with a Vaillant UniSTOR slimline cylinder and Vaillant SensoComfort controls. To help reduce installation costs, we also supported the customer through the Boiler Upgrade Scheme (BUS), successfully securing the full £7,500 government grant towards the project.
The property prior to works — a semi-detached home in Ripley with no mains gas connection
What We Did
Challenges
Every property presents unique challenges, particularly during renovation projects involving multiple contractors. The property remained occupied throughout the works and several other trades were working on-site simultaneously, requiring careful planning and coordination.
As the existing heating system had been designed around electric storage heaters, the property required a complete redesign of the heating distribution system. Pipework and radiators needed upgrading to ensure the new heat pump could operate efficiently at lower flow temperatures.
Space Challenge
The homeowner requested no visible boxing or exposed pipework, and the airing cupboard offered very limited space. A compact slimline cylinder and careful pipe routing within wall constructions addressed both issues without compromise.
The completed airing cupboard — slimline cylinder, buffer vessel and controls installed cleanly within the original space
The Vaillant aroTHERM 5kW heat pump on its new concrete plinth — compact, quiet and positioned for optimal airflow
Finally, as this was the customer’s first experience with renewable heating technology, ensuring they felt confident using and understanding the system was a key part of the project.
The Solution
Prior to starting work, we coordinated directly with the customer’s other contractors to ensure the programme ran smoothly. Detailed electrical specifications and equipment layouts were provided to the electrician completing the property’s rewire, helping avoid delays and ensuring all services were installed correctly first time.
To achieve the clean finish requested by the customer, our engineers carefully concealed flow and return pipework within wall constructions wherever practical, eliminating the need for unsightly surface-mounted boxing or trunking.
During the design phase, we identified that a chrome towel radiator would not provide sufficient heat output for the bathroom when operating alongside a low-temperature heat pump system. We therefore recommended a higher-output alternative which delivered the required performance whilst maintaining the overall design intent of the room.
Despite the limited space available, our team successfully installed a slimline hot water cylinder and all associated equipment within the existing airing cupboard — maximising storage space whilst maintaining full accessibility for future servicing.
We believe successful installations extend beyond commissioning. Following completion, our engineers carried out a comprehensive handover, explaining how the heat pump, cylinder, controls and associated components operated. The heating schedules were configured to the customer’s preferred settings, and we demonstrated how future adjustments could be made independently.
We also provided guidance on resetting the indoor and outdoor units, explained routine operation and supplied out-of-hours contact details for additional peace of mind.
Follow-Up Visit
One week after installation, we returned for a courtesy follow-up visit. The customer requested minor adjustments to hot water schedules and heating setback temperatures — which they were then able to make themselves with our engineer’s guidance.
Results
3.91
Predicted SCOP Performance
£919/yr
Estimated Annual Running Cost
£1,448/yr
Estimated Annual Saving Post-Install
6.7 tonnes
Annual CO² Saving (equiv. 33,500 miles driven)
E → B
EPC Rating Improvement*
£7,500
BUS Grant Secured
*EPC improvement was the result of both the ASHP and a Solar PV installation completed alongside.
“The lads from Henman Dunn were fantastic from start to finish. They spent nearly 2.5 hours measuring up (a lot longer than the other companies I asked to provide a quote) and gave us a couple of options and explained the differences between them. We were very impressed with the professionalism and knowledge that they clearly had, and we decided to use them as we felt comfortable that they knew what they were doing and had our best interests at heart. They took 2 days as promised to install everything and they left our house cleaner and tidier than before they came. They were very patient explaining how to use the system and even came back a week later to make sure we were ok. The Vaillant heat pump is so quiet you can hardly hear it when it’s on and the house is lovely and warm in every room. I would 100% recommend Henman Dunn to anyone wanting an air source heat pump — they have been great!”
