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Tick Tock, Time Bomb: The Dangers of Neglected Unvented Cylinders


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Set amidst the towering heights of Salford Quays, these luxury apartments' sleek, modern architecture evokes a sense of sophistication and cosmopolitan living. Located just a stone's throw from MediaCityUK, the area bustles with young professionals and city dwellers eager to take advantage of the convenience and amenities of this vibrant neighbourhood. On the 13th floor of one of Salford Quays' most exclusive addresses, the DDWilson team embarked on our latest heating mission - installing a new electric boiler system. Surrounded by the towering pillars of urban living, we got to work, determined as always, to deliver comfort and safety to the residents of this stylish community.

The Discovery

Upon visiting the apartment in Salford Quays, our heating engineer Tristan made a concerning discovery - the existing unvented hot water cylinder had not been adequately maintained for some time. Though these cylinders provide outstanding performance when cared for properly, neglecting maintenance can be extremely dangerous. The pressurised water inside an unvented cylinder must have the means to safely expand when heated, controlled by the expansion vessel and pressure relief valves. Tristan's expert eye saw the telltale signs of neglect in this case. The pressure relief valves malfunctioned and could no longer safely discharge excess pressure. Even more troubling, hastily wiped-away scorch marks around the cylinder connections indicated that dangerously high pressure had caused steaming water to leak. It was clear to the team this long-neglected unvented cylinder posed a severe safety hazard to the building's residents. Urgent replacement would be needed.

The Dangers

Upon closer inspection, Tristan unearthed some troubling signs – malfunctioning pressure reliefs and indications of frothing steam hidden under hastily erased scorch marks. These were unmistakable red flags that voiced the urgency of intervention. The peril of neglecting such maintenance was all too apparent. Without it, the pressurised water inside the cylinder could pose a significant hazard akin to a ticking time bomb. Proper expansion is the key to safety in these systems, regulated by the all-important expansion vessel and its pressure relief features.

If the pressure relief valves fail, the pressure can build to dangerous levels. An explosion can occur, spraying superheated water and steam throughout the building. The scorch marks indicated previous failures, which were covered by whipping away the marks. 

Frothing and bubbling inside the cylinder are also very concerning. The Frothing and bubbling is likely due to limescale buildup corroding the metal and releasing hydrogen gas into the water. A spark could cause a catastrophic explosion. The lack of maintenance created an urgent hazard that threatened the safety of all the building's residents. Quick action was required to isolate and replace the faulty system before disaster struck.

Taking Action

When Tristan first visited, he immediately took measures to isolate the potential hazard, ensuring the safety of the building's residents. The isolation involved shutting off the water and power supply to the faulty, unvented cylinder and advising residents to refrain from using hot water until the issue could be addressed appropriately. Recognising the urgency of the situation, the team at DDWilson sprang into action to source a replacement system. We have longstanding relationships with the top manufacturers of electric boilers and unvented cylinders, allowing us to quickly select an appropriate new model that would meet the needs of this building. Within days, we had the latest electric boiler and unvented cylinder on order and ready for installation. The safety and comfort of our customers are always the top priority. We minimised disruption and risk by isolating the faulty system and rapidly arranging for a new one. Our expertise and responsiveness demonstrate our commitment to delivering the best possible service.

Installation Day: A New Beginning

With the new system in hand, Tristan is back on site, ready to bring warmth and safety back to the bustling life in Salford Quays. Installation days like these are what we live for at DDWilson – the opportunity to ensure the comfort and well-being of our communities. 

The team works diligently, carefully removing the old, faulty system. Years of neglect have taken their toll, but Tristan and his crew carefully handle the aged parts. This system served its time, but now it's time to retire it safely. With the outdated boiler and cylinder removed, the real work begins. Meticulously following best practices, the team installs the new system, carefully connecting all parts securely and correctly. Tristan inspects their work, ensuring the highest quality installation. 

After a long day of intense focus, the moment of truth arrives. Tristan flips the switch, firing up the new boiler for the first time. As the system hums to life, warmth floods the apartment. The residents sigh in relief, welcoming the return of their heat and hot water. Tristan and his team tidy up, eager to see the new system sustain the comfort and safety of Salford Quays for years to come. As they pack up, residents stop in to share their gratitude. Installation days like this remind the DDWilson team why they do what they do - to keep their community warm, safe, and happy.

The New System - Bringing Comfort and Safety

Our new electric boiler and unvented cylinder aren't just replacements; they symbolise our commitment to providing the community with reliable, efficient, and safe heating solutions. 

This state-of-the-art electric boiler offers several benefits:

- Highly energy efficient operation, helping lower energy bills

- Compact, lightweight design that's easy to install and service  

- Extremely quiet operation for minimal disruption

- Built-in frost protection for year-round peace of mind

The electric boiler connects to the equally high-performing unvented cylinder to provide ample hot water on demand. Key features of the new cylinder include:

- Large capacity of up to 300 litres to meet the high demand

- Dual stainless steel heating coils for maximum efficiency 

- Durable stainless steel construction for longevity

- Multiple safety features like pressure relief valves 

Together, the new electric boiler and unvented cylinder deliver the comfort, convenience, and safety that residents depend on. We're proud to provide a system that aligns with our commitment to service excellence.

Annual Maintenance

Safety and efficiency go hand in hand with an unvented cylinder, which is why annual maintenance checks are necessary. At DDWilson, we ensure customers receive the required Part O G3 certification to guarantee the system's safety and performance. Our technicians conduct a series of thorough safety checks during the certification process. All components, including the expansion vessel pressure, temperature/pressure relief valve, filter, and expansion relief discharge pipework, are inspected. We test the system's pressure and expansion capabilities to verify proper operation. Adjustments and replacements are made wherever needed to satisfy the stringent requirements of Part O.

With the Part O G3 certification, customers gain the assurance that potential hazards have been identified and addressed. Our experienced team promptly corrects any issues threatening the system's safety. We take our responsibility seriously when it comes to managing the complexities of an unvented cylinder. Our annual maintenance provides the vigilance and care required to preserve the system's integrity.

Safety and satisfaction are our top priorities. With DDWilson's diligent annual maintenance, customers can enjoy reliable, efficient hot water with confidence and peace of mind. The Part O certification is the stamp of approval homeowners deserve.

Looking Ahead

As we wrap up today's installation, high above the vibrant life of Salford Quays, we can't help but feel a sense of pride. Pride in our team's dedication, commitment to safety, and community's trust in us.  

DDWilson Gas & Heating Engineers is more than just a service provider; we're a part of your daily comfort and safety, ensuring that even high above the ground, you feel the warmth and reliability of the home. Our customers know they can depend on us for expert service, quality installations, and attentive maintenance. The relationships we build in communities like Salford Quays are founded on years of trust earned through hard work and integrity.

That trust motivates us daily to deliver solutions that bring comfort and peace of mind to every home and business. Our team feels honoured to be welcomed into your lives and relied upon to keep you safe and warm. We don't take that responsibility lightly. The pride we feel with each job well done comes from knowing we've maintained your confidence. 

As we continue serving the North West, that pride will guide us. Pride arises from trust—the trust you place in DDWilson.

Our Commitment - To Safety, Reliability, Efficiency

At DDWilson Gas & Heating Engineers, our commitment extends beyond the installation. We aim to give our customers complete peace of mind regarding their heating systems. Safety is always our number one priority. We take every precaution to isolate potential hazards and ensure the well-being of residents during installations. With annual Part O g3 certifications, we guarantee our community's ongoing safe operation of unvented cylinders. Reliability goes hand in hand with safety. Using high-quality components from trusted manufacturers and performing diligent maintenance; we deliver heating systems that provide consistent comfort and performance. Our customers can rest easy knowing their homes are in good hands.

Efficiency matters, too. We help homeowners maximise energy savings while minimising environmental impact. With new electric boilers and unvented cylinder installations, we bring the latest energy-efficient technology into local homes and apartments. At DDWilson, your comfort, safety, and savings are our commitment. We aim to deliver that promise during every installation and long after through ongoing maintenance and service. Our customers are like family, and we treat every home as our own.


Revisiting the towering heights of Salford Quays reminds us of the trust placed in our hands. Our mission was clear—to replace the neglected, unvented cylinder and restore safety and comfort. Led by Tristan's expertise, we isolated the hazard and installed a new electric boiler and cylinder, bringing back reliable performance. This symbolises our commitment to delivering solutions that enable our customers to feel the warmth of home, even high above the ground. The work continues. With annual Part O g3 checks, we'll ensure this system stays safe and efficient for years. We're proud to be a part of your daily life and will continue to dedicate ourselves to service across the North West.

Stay tuned for more stories from the field. At DDWilson, you're always in good hands. Call us to experience comfort and safety delivered.

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