Unvented hot water cylinder repairs
in London
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what you need
No call centres, call 020 8682 2244 to speak directly with one of our experienced engineers about unvented hot water cylinder repairs within our London service area. Prefer to message us instead? Send an enquiry and we’ll get back to you within the hour.
Our unvented hot water cylinder repair service in London
Hot water is essential for comfort and convenience in any home. At Maintracts Services, our experienced heating engineers provide a reliable unvented cylinder repair service designed to restore your hot water supply quickly and efficiently. Whether you're experiencing a drop in pressure, a leak from the tundish overflow pipe, or suspect a cylinder thermostat fault, we’re here to help.
We work with all major models of unvented hot water cylinders, ensuring safe, compliant repairs in line with Building Regulations G3. From replacing a temperature and pressure relief (TPR) valve to inspecting the pressure reducing valve or expansion vessel, we’ll ensure your system maintains the right performance and safety standards.
Is your hot water cylinder vented or unvented?
Two of the most common types of hot water systems are vented and unvented cylinders. The suitability of each depends on your property and the available cold mains supply. Unvented hot water cylinders are connected directly to the mains, providing high water pressure without the need for a separate storage tank. These systems are typically fitted with components like a temperature and pressure relief (TPR) valve, pressure reducing valve, and expansion vessel to ensure safe and efficient operation.
In contrast, vented hot water cylinders are supplied by a large cold water storage tank, often installed in the loft. Water flows down through a vent pipe into the cylinder, where it's heated. In this setup, the water pressure is determined by the height of the storage tank. If you're unsure which type you have, our experienced engineers can assess your system and recommend the appropriate repair or cylinder re-pressurisation if needed.
Common faults with
unvented hot water cylinders
There are several issues that can affect the performance of your unvented hot water cylinder. While some may seem minor, others require urgent attention from a G3-qualified unvented cylinder engineer to ensure safety and restore proper operation.
Typical faults we deal with include:
- Malfunctioning controls and safety devices
- Cylinder thermostat faults
- Power loss from tripped circuit breakers
- Failed expansion vessels, faulty pressure reducing valves, or defective temperature and pressure relief (TPR) valves
These issues can cause noticeable symptoms such as:
- No hot water from taps
- Fluctuating or low water pressure
- Reduced flow rate
- Water leaking or discharging when not in use
If your system is showing any of these signs, whether you're dealing with a tundish overflow pipe leak, cylinder re-pressurisation issue, or complete hot water loss, our expert team is ready to help. We aim to attend to and repair faults within 24 hours, restoring your hot water quickly, safely, and efficiently.
Hot water cylinder experts for trusted brand repairs
At Maintracts Services, our engineers are experienced in repairing all major brands of unvented hot water cylinders. Whether your system is showing signs of a pressure relief valve (PRV) fault, a faulty immersion thermostat, or requires expansion vessel replacement, we can quickly diagnose and resolve the issue.
We regularly work on models from leading manufacturers, including:
- Heatrae Sadia Megaflo
- Gledhill Pulsacoil
- Santon
- Premier Plus
- Boilermate
- Systemate
- Joule
- Cyclone
- DPS - Dedicated Pressure Systems
- Heatbank
- Ariston
- Oso
- RM cylinders
- Telford
- Range Tribune
Hot water cylinder installation and servicing in London
Maintracts is trusted by homeowners across London for fast, reliable, and professional service. In addition to repairs, our engineers handle full hot water cylinder installations and routine servicing across London.
Unvented hot water cylinders are pressurised systems that must be checked annually. Key components like the expansion vessel and pressure relief valve need inspection to stay safe and compliant with Building Regulations G3. Servicing every 12 months helps prevent faults and keeps your system working efficiently.
Call 020 868 22244 to speak directly to an experienced professional. Delivering customer excellence since 1974.
Keep Your
Boiler Running Smoothly
At Maintracts Services, our Gas Safe registered engineers provide comprehensive boiler servicing to keep your heating and hot water system efficient, safe, and reliable. Many boiler manufacturers require annual servicing as part of their guarantee, so skipping it could mean missing out on valuable protection — especially if your system includes an unvented hot water cylinder.
Scheduling your service in the summer has added benefits: avoid the winter rush, address potential issues early, and ensure your boiler and cylinder are ready when you need them most. Regular servicing also helps reduce energy bills and prevent costly breakdowns caused by issues like a cylinder thermostat fault or immersion heater element failure. Trust our experienced team to keep your system in top condition.
Boiler expertise for London customers
We offer a range of specialist boiler services to ensure your heating and hot water systems receive the expert support they need. From cylinder re-pressurisation to boiler servicing and repair, our Gas Safe registered engineers provide reliable, compliant solutions for homes across London.
No matter the scope of the issue, whether it’s a pressure relief valve (PRV) fault or a complete system breakdown, our team delivers the expertise you can trust.
Expert boiler services
for London customers
We offer a wide range of specialist boiler and hot water system services to ensure your property’s heating and hot water are operating safely and efficiently. Whether you're dealing with pressure issues, planning a system upgrade, or need routine maintenance, our expert team of Gas Safe registered engineers is here to help. From unvented cylinder installation to full system diagnostics, we ensure every job meets building regulations G3 and delivers lasting performance.
Contact
Maintracts Services
Ltd
Call 020 8682 2244 to speak with our experienced team and find out how we can help. We handle all residential and commercial plumbing, heating, electrical, and drainage services across London, completed efficiently, professionally, and to the highest possible standard.
Whether you need urgent unvented hot water cylinder repairs, boiler work, or general maintenance, our engineers are ready to assist.
Frequently asked questions about unvented hot water cylinders in London
What is an unvented hot water cylinder?
An unvented hot water cylinder is a sealed, pressurised system that is fed directly from the cold mains supply. It delivers high-pressure hot water to taps and showers without the need for a separate cold water storage tank. These systems are common in modern London homes and are known for their efficiency and fast water flow.
How do I know if my cylinder needs repair?
Signs your unvented cylinder may need repairing include fluctuating water pressure, no hot water, water escaping from the tundish overflow pipe, or unusual noises. If you notice any of these issues, contact our G3-qualified engineers for a same-day inspection anywhere in London.
Can I repair an unvented cylinder myself?
No. Due to the pressurised nature of these systems and UK safety regulations, repairs must be carried out by a G3-qualified unvented cylinder engineer. DIY repairs are unsafe and can invalidate your system's warranty. Our qualified team at Maintracts Services is fully certified to handle these repairs throughout London.
What does a G3-qualified engineer do?
A G3-qualified engineer is certified to install, maintain, and repair unvented hot water cylinders in accordance with Building Regulations G3. They have the training required to safely manage pressurised systems, including components such as temperature and pressure relief valves and expansion vessels.
How often should an unvented cylinder be serviced?
To stay compliant and maintain performance, your unvented hot water cylinder should be serviced once every 12 months. Our team provides reliable annual cylinder servicing across London, helping prevent breakdowns and extending the lifespan of your system.
Why is my cylinder leaking from the tundish?
A leak from the tundish usually indicates an issue with the pressure relief valve (PRV) or an over-pressurised expansion vessel. This needs urgent attention to prevent further damage. We can investigate and carry out prompt repairs anywhere in London.
How do I fix low hot water pressure?
Low pressure in an unvented system could be caused by issues with the cold mains supply, a faulty pressure reducing valve, or trapped air. Our engineers will quickly identify the cause and restore correct pressure throughout your hot water system.
What should I do if the expansion vessel fails?
If the expansion vessel in your cylinder fails, you may notice frequent water discharge from the tundish or inconsistent hot water. Contact us for a fast response, we offer expansion vessel replacement as part of our repair services in London.
When does the pressure relief valve need replacing?
A pressure relief valve (PRV) should be checked during routine servicing. If it’s leaking, not releasing pressure when required, or causing safety issues, it may need replacement. Our engineers are qualified to replace PRVs across all major cylinder brands.