Unvented Cylinder Services
Expert installation, servicing, and repairs for unvented hot water cylinders. Our G3 qualified engineers ensure your system delivers powerful, reliable hot water.
Why Choose Our Cylinders
- G3 qualified engineers
- All major brands
- Annual servicing
- Emergency repairs
What We Cover
Why Unvented Cylinder Services Matters
Our Cylinders Process
**Book Your Cylinder Service** - Contact us to book your annual unvented cylinder service. We can service your cylinder on its own, or if you have both a boiler and unvented cylinder, ask about our combined service package (Boiler + Cylinder for £180) which offers better value than booking separately.
**Appointment Confirmation & Engineer Tracking** - You'll receive confirmation of your appointment, and on the day, we'll send you a text when your G3-qualified engineer is on the way. Our tracking link lets you see when to expect us - no more wasted days waiting around.
**Visual Inspection & Safety Assessment** - Our engineer will examine your unvented cylinder and associated pipework, checking for signs of corrosion, leaks, or damage. We'll verify that safety devices are present, correctly positioned, and haven't been tampered with. We'll also check that the installation still complies with current Building Regulations.
**Temperature & Pressure Relief Device Testing** - We'll test all safety devices including the temperature relief valve, pressure relief valve, and expansion vessel. These critical components must operate correctly to prevent dangerous pressure buildup. We'll verify that discharge pipes terminate safely and meet regulatory requirements.
**Expansion Vessel & Pressure Testing** - The expansion vessel is crucial for absorbing pressure increases as water heats up. We'll check the vessel's pre-charge pressure and test its operation. If the vessel has lost pressure or failed, it will need recharging or replacement to ensure system safety.
**Performance Checks & Adjustments** - We'll verify water temperatures, check thermostat operation, and test heating elements (on electric cylinders) or coil performance (on indirect cylinders). We'll ensure your cylinder is heating water efficiently and maintaining the correct stored water temperature.
**Service Report & Recommendations** - After completing your service, you'll receive a detailed report confirming all safety tests carried out and any recommendations for repairs or component replacement. We'll explain our findings and provide quotes for any additional work needed, allowing you to make informed decisions.
Common Cylinders Issues We Fix
Failed Temperature & Pressure Relief Valves
These safety-critical valves can seize up or deteriorate over time, especially if never tested. During our service, we test these devices to ensure they'll operate if pressure or temperature exceeds safe limits. A failed relief valve is a serious safety concern and must be replaced immediately. Signs include constant dripping from the overflow or, more dangerously, no water discharge when tested.
Expansion Vessel Pressure Loss or Failure
The expansion vessel absorbs pressure increases as water heats and expands. If it loses its air pre-charge or the internal diaphragm fails, you'll see symptoms like water discharging from the pressure relief valve, pressure gauge fluctuations, or reduced hot water pressure. This is one of the most common unvented cylinder problems and can cause expensive water damage if not addressed.
Limescale Buildup in Hard Water Areas
Kent has particularly hard water, which causes limescale accumulation inside cylinders and on heating elements. This reduces efficiency, slows heating times, and can eventually cause element failure or cylinder leaks. During servicing, we can assess limescale levels and recommend descaling or inhibitor treatment to protect your investment.
Thermostat Faults & Temperature Issues
If your water is too hot (scalding risk) or not hot enough, the thermostat may need adjustment or replacement. We'll test water temperatures and verify that thermostats are operating within safe parameters. Modern regulations require stored water to be kept at 60°C to prevent legionella growth while being safe to use.
Leaking Cylinder or Corroded Components
Internal corrosion can cause cylinder leaks, often starting small but potentially leading to major water damage. We check for signs of corrosion, particularly at welded seams and immersion heater bosses. External corrosion on pipework and fittings is also common, especially in cupboards with poor ventilation. Early detection allows planned replacement rather than emergency repairs.
Annual Service Compliance for Landlords
Landlords with unvented cylinders in rental properties must ensure annual servicing by G3-qualified engineers. Failure to maintain proper service records can result in insurance issues if something goes wrong and potentially breach landlord safety obligations. We provide comprehensive service documentation for landlord compliance.
Unvented Cylinder Services Pricing
Our unvented cylinder service costs £120 and includes all safety device testing, performance checks, and a detailed service report. For customers with both a boiler and unvented cylinder, our combined service package at £180 offers excellent value - saving you £60 compared to booking each service separately. All our engineers are G3-qualified as required by law, and all prices include VAT with no hidden costs. Any parts or repairs needed beyond the standard service will be quoted separately before work begins.
Unvented Cylinder Service
Combined Boiler + Cylinder Service
All prices include VAT. G3-qualified engineer certification is included as standard. If your annual service identifies parts that need replacement, we'll provide a clear quote before proceeding with any additional work. Combined boiler and cylinder servicing saves £60 versus individual services.
Frequently Asked Questions
What does G3-qualified mean and why is it important?
G3 refers to Approved Document G of the Building Regulations, which covers unvented hot water systems. Anyone who installs, services, or repairs unvented cylinders must hold the G3 Unvented Hot Water qualification. This ensures they understand the safety-critical nature of pressurised hot water systems and can work on them safely and legally. All our engineers are G3-qualified, which means you can trust that the work complies with legal requirements.
How often should I have my unvented cylinder serviced?
We recommend annual servicing for unvented cylinders. This is essential to test safety devices like pressure relief valves and expansion vessels, which protect against dangerous pressure buildup. Most manufacturers require annual servicing to maintain warranties, and landlords must ensure annual servicing for legal compliance. Regular maintenance also prevents efficiency loss and extends the life of your cylinder.
What brands of unvented cylinders do you work with?
We service and repair all major unvented cylinder brands including Megaflo (the most common brand), Heatrae Sadia, Gledhill, Range Tribune, Telford, OSO, and many others. Our engineers have experience with both direct (electric immersion) and indirect (heated by boiler) cylinders, and we can source parts for all common makes and models.
Why is water dripping from the overflow pipe?
Water dripping from the overflow (tundish discharge) usually indicates a problem with the pressure relief valve or expansion vessel. The most common cause is expansion vessel failure - when the vessel loses its air charge, excess pressure from heating has nowhere to go except out through the relief valve. This needs attention promptly as constant water discharge can cause damage and indicates the safety system isn't working correctly.
Can you install a new unvented cylinder if mine needs replacing?
Absolutely. We're fully qualified to install unvented hot water cylinders in accordance with Building Regulations. If your cylinder is beyond economical repair, we'll discuss replacement options including cylinder size, brand recommendations, and whether direct or indirect heating suits your needs. We'll provide a free, no-obligation quote for a complete installation including all required safety devices and pipework modifications.
Is the combined boiler and cylinder service worth it?
If you have both a boiler and an unvented cylinder, our combined service package at £180 saves you £60 compared to booking each service separately (£120 + £120 = £240). It's also more convenient as both services are completed in one visit. For homeowners with this combination, it's by far the most cost-effective way to maintain both systems annually.
What happens if my cylinder fails and needs replacing urgently?
We carry some common unvented cylinder parts and can often resolve issues like failed thermostats or relief valves on the same day. For complete cylinder replacement, we can typically arrange installation within a few days and will recommend temporary solutions in the meantime. We understand that losing hot water is disruptive and will prioritise getting you back up and running as quickly as possible.
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Unvented Cylinder Services Across Kent
We provide unvented cylinder services throughout Kent. Click on your area to learn more about our local service.
Our Other Services
Boiler Repairs
Fast, reliable repairs for all boiler makes and models. Same-day emergency service available.
Boiler Servicing
Annual servicing to keep your boiler running safely and efficiently. Helps maintain warranty.
Smart Thermostat Installation
Upgrade your heating control with a smart thermostat. Save energy and money.
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Get in touch today for professional unvented cylinder services from Gas Safe registered engineers.