Project Spotlight: Total Plant Room Refurbishment at Andover Nursing Home

Andrew Lewis
Dec 26, 2025
3 min read

At Andover Gas Engineers Ltd, we don’t just swap boilers; we solve systemic plumbing and heating failures. Our recent full refurbishment at Andover Nursing Home is a prime example of how modern engineering can fix long-standing operational headaches and drastically reduce running costs.

The Challenge: Beyond Inefficiency

The facility was struggling with aging 250kW Hoval conventional boilers that were operating at roughly 70% efficiency. Beyond the high fuel bills, the nursing home faced two critical "hidden" problems:

System Erosion: Due to Andover's hard water and heavy daily demand, the pipework was being "sandblasted" from the inside by scale. This led to frequent, disruptive pinhole leaks throughout the building.
Pressure Failures: At peak times, the most remote residential rooms suffered from severe pressure drops, leaving residents with inadequate water supply.

The Solution: A Complete Technical Overhaul

We stripped out the bulky, scaled-up Hoval tanks and boilers to make room for a streamlined, high-performance setup:

The Power: We installed three 125kW Worcester Bosch high-efficiency condensing boilers. Remarkably, all three of these new units combined occupy less floor space than just one of the original Hoval boilers.
The Protection: To stop the cycle of leaks, we installed a Sentinel Electrolytic Scale Reducer and Micro Filter. This "fit and forget" solution requires no salt supply and no expensive servicing, yet it protects the entire hot and cold pipework from abrasive scale.
The Pressure Fix: We installed a large break tank and a twin-set booster pump system. This ensures that even at peak demand, the furthest reaches of the facility have constant, high-pressure water.
The Control: We replaced manual guesswork with a Worcester Bosch digital sequencer and Hive remote internet controls, allowing the management to monitor the system via the web.

The Result: Reliability Restored

By replacing 500kW of inefficient plant with a 375kW condensing cascade and adding a booster set, we have provided the home with a system that is more powerful, cheaper to run, and far more resilient.

By moving from the old 70% efficient boilers to the Worcester Bosch GC7000WP units (with a 96.3% seasonal efficiency), we have significantly reduced the facility's carbon footprint and fuel spend. Crucially, the new filtration and scale treatment means no more pinhole leaks and none of the costly damage or resident disruption that follows them. The residents now enjoy constant water pressure, and the management has total peace of mind that their infrastructure is protected.

System Specifications: Worcester Bosch Condens 7000 WP (125kW)

Energy Performance: ErP Class A rated with a seasonal space heating efficiency of 96.7% (Part L2B).
Peak Efficiency: Delivers up to 109.3% net efficiency when operating in part-load condensing mode.
Advanced Modulation: Features a 1:6 modulation ratio, allowing each 125kW unit to scale down to just 24.1kW. This precision matching prevents "short-cycling" and significantly reduces daily fuel consumption.
Future-Ready: Fully certified to run on a 20% Hydrogen gas blend, protecting the facility against upcoming changes to the UK gas grid.
Environmental Impact: Class 6 NOx emissions (as low as 35mg/kWh), making it one of the cleanest commercial combustion systems available.
Intelligent Sequencing: Integrated with Bosch digital controls to manage the cascade, ensuring even wear across all three boilers and maximum uptime.

The entire system is protected by a Sentinel Kalguard Electrolytic Scale Inhibitor. This commercial-grade protection ensures these high-efficiency specs are maintained for the life of the boiler by preventing limescale buildup in the heat exchangers and eliminating the risk of pinhole leaks in the building's pipework. Want to see the full technical breakdown? [Click below to download the Project Comparison PDF]