When Historic Buildings Need Modern Solutions: Planning a Major Commercial Heating Liverpool Transformation
- Chris Welford
- 5 days ago
- 8 min read
Updated: 18 hours ago
Published: November 2025 | Case Study Part 1 of 3
Some heating projects are more than just technical challenges; they're opportunities to support vital community institutions while showcasing the complexity and precision required for large-scale commercial heating work. When the League of Welldoers, a Liverpool charity that has served the community since 1893, needed a complete heating system replacement, they turned to DD Wilson Gas and Heating Engineers Ltd to deliver a solution that would keep their historic building warm and their operations running smoothly.
This is the first instalment in our three-part case study series documenting a major commercial heating project that saw DD Wilson transform an antiquated, gravity-fed heating system into a modern, efficient cascade boiler installation, all while keeping the building operational for the vulnerable community members who depend on it daily.
About The League of Welldoers: A Liverpool Institution
Located at 119-133 Limekiln Lane in Liverpool (L5 8SN), the League of Welldoers operates from the Lee Jones Centre, a charity that has been caring for the local community since 1893. For over 130 years, this remarkable organisation has provided essential services including:
Activities for all ages (bingo, chair exercises, outings, tea dances)
Weekday lunches for community members
A charity shop supporting residents
Community spaces for gatherings and events
The building itself is a testament to Liverpool's charitable heritage, a substantial multi-storey facility with approximately 72 rooms serving dozens of people daily. However, its heating system had become a significant liability, relying on outdated, increasingly unreliable technology.
The Initial Contact: How The League of Welldoers Found DD Wilson
Tony, the Commercial Manager at the League of Welldoers, first heard about DD Wilson through a trusted recommendation, one of the charity's trustees who had personal experience with our work. In the commercial heating sector, word-of-mouth recommendations carry significant weight, particularly when they come from people who understand the stakes involved in keeping community facilities operational.
"I actually heard about you through a friend," Tony explained during our post-project testimonial interview. "You were highly recommended by a friend who's one of the trustees of the charity. That's how we heard about you."
For a charity operating on tight budgets and responsible for vulnerable community members, choosing the right heating contractor wasn't just about finding the lowest price; it was about finding a partner who understood the unique challenges of operating a community facility.
As a Gas Safe-registered company (Registration No. 583586), DD Wilson was well-positioned to handle the complexity of this commercial project. Our experience with both domestic and commercial heating installations across Liverpool, Wirral, and surrounding areas meant we understood the regulatory requirements, logistical challenges, and technical specifications required for a building of this size and importance.
The Site Survey: Uncovering the Extent of the Challenge
When our team conducted the initial site survey, we discovered a heating system that was not just outdated—it was potentially dangerous to upgrade without a complete overhaul.
The Existing System: A Relic from Another Era
The League of Welldoers building operated on what heating engineers call an "open vented" system—a gravity-fed arrangement that relied on large storage tanks on the building's roof. Here's what we found:
The Heating Distribution System:
Open vented system operating at extremely low pressure (well below 1 bar)
Feed and expansion tank on the roof, providing gravity-fed pressure
Ageing radiators sized for older, less efficient heating technology
Imperial pipework (1.5 inch/42mm) dating back decades
No zoning or individual section control
Pipework showing signs of corrosion and age-related deterioration
The Hot Water System:
Large gravity-fed cold water storage tank on the roof
No secondary return circulation (creating legionella risks in a public building)
Hot water is heated separately from the central heating system
Multiple outlets serving kitchen facilities, communal toilets, and utility areas
The Critical Problem:
Modern commercial boilers operate at system pressures exceeding 1 bar to ensure efficient heat distribution and proper circulation. The existing pipework, designed for low-pressure gravity systems, would be at serious risk of failure if connected to a modern high-pressure boiler system.
Attempting to simply replace the boilers without addressing the entire distribution system would be like putting a high-performance engine in a car with worn-out tyres and ancient brakes, technically possible, but practically dangerous and ultimately ineffective.
The DD Wilson Solution: A Complete System Transformation
After our comprehensive site assessment, we presented the League of Welldoers with a solution that addressed not just their immediate heating needs but also their long-term reliability, safety, and efficiency requirements.
Our Proposed Approach:
1. Sectionalised Zoning Strategy
Rather than treating the building as a single heating zone, we proposed dividing it into five separate sections. This approach would deliver multiple benefits:
Allow sections of the building to remain operational during installation
Provide independent temperature control for different areas
Enable future maintenance without shutting down the entire facility
Improve overall system efficiency by heating only occupied spaces
2. Complete System Repipe
We recommended replacing all existing pipework throughout the building. This wasn't cost-padding—it was essential for several critical reasons:
Eliminate the risk of old pipework failing under modern system pressures
Convert from obsolete imperial sizing to modern metric standards
Ensure proper flow rates for efficient heat distribution
Provide warranty coverage for the entire system, not just components
The new pipework design included:
Modern copper press-fit technology for faster, safer installation
Proper sizing calculations for each section's heat load
Strategic routing to minimise disruption to historic building features
Professional clipping and support throughout
3. Cascade Boiler System
For heating, we specified a cascade system of six commercial boilers providing a combined output of 300kW:
3 commercial heat-only boilers for central building heating
2 Vaillant combi boilers for specific building zones
1 commercial hot water boiler for dedicated hot water production
This configuration offers significant advantages over a single large boiler:
Built-in redundancy: If one boiler fails, others continue operating
Modular efficiency: Only the necessary boilers fire based on demand
Staged heating: Ramps up gradually rather than an all-or-nothing operation
Future-proofing: Easy replacement of individual units without system downtime
4. Hot Water System with Legionella Compliance
We specified three Rinnai high-flow gas-fired water heaters for the building's hot water demands. These commercial-grade units were selected for their reliability, efficiency, and impressive 5-year manufacturer warranties. Crucially, our design incorporated a secondary return circulation system, a legal requirement under Legionella legislation (HSE ACOP L8) for public buildings. This ensures that hot water continuously circulates throughout the distribution pipework, maintaining temperatures above the threshold at which legionella bacteria can develop. The secondary return system includes time-based controls to reduce energy consumption during unoccupied hours while maintaining compliance during operational periods.
The Project Timeline: Setting Realistic Expectations
Commercial heating projects of this scale require careful scheduling to balance speed, quality, and safety. We developed a detailed project plan based on our five-section installation strategy.
Our original estimate suggested the project might take approximately 42 days (6 weeks) if we needed to work around full building operations. Competitor quotes ranged up to 82 days—nearly 12 weeks. However, our team developed an accelerated approach that ultimately delivered the project in just 21 days, completing it in half the time of our own estimate and less than a quarter of what competitors proposed.
The Five-Section Strategy:
We divided the building into five distinct zones for sequential installation:
Section 1: Hall, kitchen, and new plant room
Priority area due to kitchen hot water requirements
Installation of the central cascade boiler system (6 boilers total: 3 commercial heat-only, 2 Vaillant combi, one commercial hot water)
Installation of Rinnai water heaters for the kitchen and facilities
Establishment of a new plant room as the system's central hub
Section 2-5: Progressive installation throughout the remaining building areas
Radiator replacements in each section
New pipework distribution from the plant room to each zone
Pressure testing and commissioning of each section independently
Coordination with building users to minimise disruption
The Access Requirement:
As we made clear in our initial proposal,
"Access to all areas will be needed. Should there be an area that is inaccessible, this will delay our progress with a knock-on effect on the completion date."
Fortunately, Tony and the League of Welldoers team worked closely with us to ensure our installers could access necessary areas while coordinating around the building's activity schedule. This collaboration proved essential to the project's success.
What Made This Project Technically Complex
For readers unfamiliar with commercial heating systems, it's worth understanding what makes a project like this significantly more complex than a typical residential boiler replacement:
1. Scale and Capacity Requirements
A residential boiler might output 24-35kW to heat an entire home. The League of Welldoers, with approximately 72 rooms across multiple floors, required 300kW of heating capacity plus high-volume hot water production. This is roughly equivalent to heating 10-12 typical homes simultaneously, distributed across a complex, multi-storey building with varying heating requirements in different zones.
2. Regulatory Compliance
Commercial installations must meet stringent requirements, including:
Building Regulations Part L (Conservation of fuel and power)
Gas Safety (Installation and Use) Regulations
Legionella control requirements (HSE ACOP L8)
Disabled Facilities Act considerations for accessible buildings
Local authority building control notifications and inspections
3. System Complexity
Unlike a simple residential setup, this project involved:
Cascade boiler sequencing and control
Multi-zone temperature management
Secondary return circulation with time-based controls
Condensate neutralisation systems
Pressure management across varying building heights
Integration with existing building management requirements
4. Risk Management
Working in an occupied building serving vulnerable people requires exceptional attention to:
Health and safety protocols
Dust and debris control
Clear communication about temporary service interruptions
Emergency backup procedures
Protection of building contents and historic features
All of this must be delivered while maintaining the professional standards expected of a Gas Safe registered contractor with a reputation for quality work across Liverpool and the Wirral.
Looking Ahead: The Installation Phase
This comprehensive planning and assessment phase set the foundation for what would become a remarkably successful installation. In Part 2 of this case study, we'll take you through the actual installation process, including:
The technical innovations that accelerated the timeline
How our team worked around the building's daily operations
The press-fit technology that eliminated hot work hazards
Specific challenges encountered and how we solved them
Day-by-day progress through the five-section installation
The transformation from a 130-year-old gravity-fed system to a modern, efficient commercial heating installation involved more than just technical expertise; it required careful coordination, innovative problem-solving, and a genuine commitment to supporting a vital community institution.
For commercial property managers, facility operators, or business owners facing similar heating challenges, this project demonstrates the importance of thorough planning, comprehensive solutions, and selecting a contractor who understands that commercial heating is about more than just installing equipment; it's about maintaining operations, ensuring safety, and delivering long-term reliability.
Need Commercial Heating Services in Liverpool or the Wirral?
DD Wilson Gas and Heating Engineers Ltd provides comprehensive commercial heating services across Liverpool, Wirral, and surrounding areas. Our Gas Safe-registered engineers (Registration No. 583586) have the expertise and equipment to handle projects of any scale, from small commercial boiler replacements to complete system transformations, such as the League of Welldoers project.
Our commercial heating services include:
Complete heating system design and installation
Hot water systems for commercial facilities
Legionella risk assessments and control
Energy efficiency upgrades
Contact DD Wilson today for a professional commercial heating assessment:
Phone: 0151 739 8945 Email: info@ddwilson.com Website: www.ddwilson.com Address: Unit 8, Redwood Point, Woodward Road, L33 7UZ, United Kingdom
Emergency commercial heating support available—because we understand that heating failures in commercial buildings can't wait.
CONTINUE TO PART 2
"Installation & Technical Execution"
In the next instalment, we'll take you behind the scenes of the actual installation process, revealing the technical innovations and problem-solving that enabled DD Wilson to complete this major commercial heating transformation in just 21 days.
Gas Safe Registration: 583586
