Status - Completed and operational
Comprehensive water treatment upgrade for long-term efficiency, hygiene and resilience
“Sidon Water’s solution reduced scale, improved performance, and restored our confidence in water quality across the hotel.”
The challenge
The Sheraton Heathrow Hotel, part of the global Marriott International portfolio – one of the world’s largest hospitality groups – faced persistent challenges with hard water and limescale management that were affecting both operational performance and guest experience.
While Marriott’s brand standards demand consistent water quality and hygiene across its portfolio, Sheraton Heathrow had been relying on traditional ion-exchange salt softeners that had declined in effectiveness over time. A detailed site evaluation identified:
- Oversized and inefficient softening equipment relative to current water demand
- Extensive limescale build-up in hot water systems, plant, pipework, kitchen areas and guest outlets
- Maintenance implications impacting energy efficiency, system hygiene and asset performance
Scale deposition throughout the building raised concerns about energy waste, increased maintenance intervention and long-term asset health – particularly given the critical nature of hot water systems in a busy airport-adjacent hotel. At the same time, the property needed to maintain hospitality-grade water quality for guest bathrooms, kitchens and service areas, in line with broader Marriott quality expectations.
These challenges underscored the need for a water treatment solution that went beyond traditional softening and aligned with both operational performance goals and broader corporate standards for hygiene and guest experience
Project Solution
Sidon Water partnered with Sheraton Heathrow to design and implement a tailored, two-pronged water treatment solution that delivered both immediate remediation and long-term system resilience.
Duplex Ion-Exchange Softening
A correctly sized modern duplex ion-exchange softening system was installed to replace the underperforming legacy equipment. The new system was carefully specified to match actual daily water demand and included:
- Optimised sizing and footprint for the hotel’s current requirements
- Retention of bulk salt storage and automated refill systems to reduce manual handling
- Consistent delivery of high-quality softened water to kitchens, guest bathrooms and other priority areas
This ensured that hospitality-critical soft water performance was maintained without the inefficiency and variability of the legacy installation.
Integro™ Electro-Chemical Water Conditioning
To address historic scale and provide performance resilience, Sidon Water deployed its Integro™ electro-chemical conditioning technology throughout hot and cold water circuits.
Unlike conventional softening alone, Integro™ maintains continuous conditioning to prevent new scale formation while gradually reducing existing mineral deposits. It also supports ongoing protection during periods when softener performance might vary — such as during service intervals, salt replenishment or unexpected interruptions.
This dual approach — combining traditional softening with advanced conditioning — provided Sheraton Heathrow with both scale reduction and operational resilience, complementing the Marriott group’s emphasis on reliability and hygiene standards across its properties.
Project objectives
The key objectives for the project were to:
- Eliminate existing limescale accumulation throughout building systems
- Improve overall water quality and hygiene performance
- Support Legionella risk reduction through enhanced hydraulic and thermal efficiency
- Restore and protect hot water system performance
- Maintain hospitality-grade water quality for guest and service areas
- Reduce maintenance burden and improve asset longevity
- Align with Marriott group water quality and hygiene expectations
For deeper insights into how water quality and scale prevention support Marriott’s operational standards and brand expectations, see Sidon Water’s white paper: Water Treatment Best Practices for Marriott Hotels.
Results
Several months after commissioning, Sheraton Heathrow has reported clear and measurable benefits:
- Significant reduction in scale throughout hot and cold water systems
- Reliable performance from the new duplex softening system
- Reduced maintenance burden on outlets, plant and service equipment
- Improved confidence in water hygiene management and compliance practices
- Greater operational resilience through complementary technologies working in tandem
By combining correctly specified softening with active conditioning, the hotel has achieved a water treatment outcome that enhances both day-to-day operations and long-term system health.
Summary
Sheraton Heathrow Hotel’s water treatment upgrade demonstrates how a purpose-designed combination of ion-exchange softening and electro-chemical conditioning can deliver measurable operational value within a demanding hospitality environment — aligned with broader expectations from a global brand such as Marriott International.
This project highlights how strategic water technology specification not only solves legacy performance issues but also contributes to improved hygiene, efficiency and resilience in alignment with high corporate standards.
Evidence Photos
Related Assets
Case Studies
Sheraton Heathrow Hotel
The Sheraton Heathrow Hotel had long struggled with limescale build-up and declining performance from ageing ion-exchange softeners
Marriott Swindon
A 156-bedroom hotel in a hard water area faced severe limescale issues. After a successful trial, the hotel installed four Integro™ units, significantly improving water quality, reducing limescale, and extending equipment life.
White Papers
Marriott Hotels
Hard water is a persistent challenge for businesses reliant on high water
consumption. Limescale accumulation leads to inefficiencies, increased maintenance
costs, and potential operational risks. Sidon Water Ltd, a leader in water restructuring
technology, implemented a trial of its revolutionary Integro™ system at a Marriott
Hote
l in the UK to demonstrate its ability to
prevent and remove limescale, protect
against rust and corrosion, and optimise operational efficiency
. The results were
transformative, offering long-term sustainability and financial benefits.