Your Upgrade Options
Explore the best heating system upgrades for your home efficiency.
Open vented system to Combi
- Space-Saving: Remove bulky tanks from your loft and airing cupboard.
- Hot Water on Demand: Instantly available hot water whenever you need it.
- A Rated Energy Efficiency: Only heat the water you use, reducing bills.
- System Performance: Improved water pressure throughout your home.
- Manufacturer parts & labour warranty options to suit every budget.
- Kitchen cupboard compatible.
Upgrade to Unvented Power
Moving from a traditional gravity-fed system to an unvented cylinder transforms your home's hot water performance. Experience powerful high-pressure showers and consistent flow rates across multiple outlets simultaneously, all delivered from a space-saving, high-efficiency stainless steel unit.
Small Home / 1 Bath
A high-efficiency combi boiler is typically best, providing on-demand hot water without the need for storage tanks.
Which System Is Right for My Home?
Choosing the right heating system depends on your property size, water usage, and efficiency goals. Our experts can help you decide.
Medium Home / 2 Bath
We recommend a larger output combi or a system boiler with a fast-recovery cylinder to manage multiple showers simultaneously.
Large Home / Multi-Bath
A high-performance system boiler with an unvented hot water cylinder provides the highest flow rates for larger families.
12+ Years' Experience
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Gas Safe Registered
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System Assessment
Our professional survey ensures your new system is perfectly tailored to your property. We conduct a detailed evaluation of your current pipework, water pressure, and heating requirements to provide a fixed-price recommendation that guarantees long-term efficiency and comfort.
150+ Boilers Installed
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Care & Attention to Detail
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NVQ Level 3 Qualified
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Customer Satisfaction
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Converting to an Unvented Hot-Water Cylinder
Modern unvented cylinders store hot water while supplying it to outlets using the incoming mains water supply rather than relying on a traditional cold-water storage cistern in the loft. This results in high-pressure performance across multiple bathrooms and simultaneous outlet use.
Mains-Pressure Performance
Stored Capacity & Demand
Experience balanced high-pressure hot and cold water throughout the property, ideal for high-performance showers.
Choose from various cylinder sizes to meet the specific stored hot water capacity requirements of your household.
Safety & Provision
Includes dedicated expansion provision, safety controls, and discharge arrangements for complete peace of mind.
System Modernisation
Removal of redundant loft tanks creates space and eliminates the risks associated with open-vented storage.
Important: Suitability depends entirely on the property's incoming mains water supply flow and pressure measurements. Correct installation and commissioning by qualified specialists are essential for safety and performance.
Combi Boiler
- Instant Hot Water: Heated on demand directly from the mains.
- Space Efficiency: No hot water cylinder or loft tanks required.
- Energy Savings: Only heats water when a tap is turned on.
- Minimal Maintenance: Fewer components than a full cylinder system.
- Installation Cost: Generally more cost-effective to install.
Combi vs Unvented Comparison
Neither system is automatically better. The right solution depends on the property, water supply and household hot-water requirements.
Unvented Cylinder
- Multiple Outlets: Supplies multiple bathrooms at same high pressure.
- High Flow Rates: Ideal for properties with powerful showers and large baths.
- Hot Water Storage: Large volume of water ready for immediate high-demand use.
- Balanced Pressure: High performance at all taps throughout the home.
- Backup Power: Immersion heater provides hot water even if boiler fails.
Your Incoming Water Main Matters
The ultimate performance of your hot water system isn't determined by the boiler or cylinder alone. It starts with the water supply entering your home. Understanding potential restrictions is the first step toward a superior install.
- Older incoming water mains & lead pipework
- Small diameter supplies (e.g. 15mm copper)
- Restrictive internal pipework & long pipe runs
- Older or partially closed stop taps
- Restrictive filters, fittings, or valves
- Existing restrictions within the property boundary
Installing a larger boiler cannot create additional incoming water flow that the property does not already have available.
Unvented Cylinder Sizing Guide
Selecting the right cylinder is about more than just house size. We assess your property's total simultaneous demand to ensure you never run cold.
120L
Suited for 1-2 occupants with modest hot water needs.
150L
Common for standard 2-3 bed homes with a single bathroom.
180L
Ideal for nd bathrooms or high-flow shower requirements.
210L
Premium capacity for families with 2+ bathrooms.
250L
High demand properties with large baths or rainfall showers.
300L
Large properties with multiple occupants and high demand.
Key Selection Factors
- Number of occupants & daily usage patterns.
- Total bathrooms, baths, and specific shower flow rates.
- Simultaneous demand requirements (morning vs staggered).
- Available incoming mains water supply.
- Boiler reheat performance & recovery times.
- Dedicated installation space & recovery capability.
Capacity Overview
The capacities above are example standards provided as a guide. They are not fixed recommendations based purely on room count. Every superior install begins with a precise calculation of peak demand versus available supply.
Correct cylinder sizing should be based on the property's actual hot-water requirements rather than simply choosing a cylinder based on house size.
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Cylinder Weight & Structural Support
When selecting a hot water cylinder, it is important to consider not only its capacity but also its fully laden weight once filled with water. As a general guide, 1 litre of water weighs approximately 1 kg, in addition to the weight of the cylinder itself, associated components and pipework.
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For cylinders installed on a ground floor, suitable structural support is generally straightforward. However, installations on an upper floor or within a loft space require additional consideration, particularly with larger-capacity cylinders.
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There is no specific cylinder capacity at which additional structural support automatically becomes a requirement. The suitability of the installation depends on the cylinder's total operating weight, how that load is distributed, and the construction and condition of the supporting floor or joists.
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This becomes particularly important with 250–300 litre cylinders, which can weigh approximately 300–400 kg or more when full, depending on the model.
Loft installations require particular care, as existing ceiling joists may not have been designed to support such a significant concentrated load. A suitable load-bearing platform, strengthened joists or other structural support may therefore be required.
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Where there is any uncertainty regarding the ability of the existing structure to safely support the fully laden cylinder, appropriate structural assessment should be carried out before installation.
Pressurising an Older Heating System
Converting an older open-vented heating system may involve operating parts of the heating system under different pressure conditions, so the condition and suitability of the existing system should be considered before conversion. We do not guarantee that older components will withstand increased pressure; instead, the existing system should be assessed and any concerns discussed with the homeowner.
- Existing radiator condition
- Radiator valves
- Existing pipework
- Visible corrosion
- Existing leaks
- Previous system problems
Expert Assessment: Our specialist engineers will carefully assess the condition of your existing radiators, valves, and pipework prior to any pressure increase to ensure system integrity.
Installation Times
A full heating-system conversion generally involves considerably more work than a like-for-like boiler replacement. The scope of work is extensive, requiring precise coordination across multiple technical disciplines.
✓ Draining the existing system
✓ Removing the old cylinder
✓ New pipework
✓ Controls & electrical work
✓ Filling and testing
✓ Customer handover
*Installation time depends heavily on the existing property and proposed system. A more accurate timescale will be provided following your assessment.
✓ Removing tanks
✓ Boiler replacement or relocation
✓ Cylinder installation
✓ System cleaning
✓ Commissioning
Frequently Asked Questions
Common questions about heating system conversions. Please note that suitability depends on an individual property assessment.
Can I remove my tanks from the loft?
Yes, converting to a combi or unvented system typically allows for the removal of cold-water storage tanks, reclaiming valuable loft space.
Can I remove my old hot-water cylinder?
If you convert to a combi boiler, the cylinder is removed entirely. With an unvented system, your old vented cylinder is replaced with a modern high-pressure unit.
Can any house be converted to a combi boiler?
Most homes can, provided the incoming mains water flow and pressure meet the technical requirements for the boiler to operate effectively.
Will a combi improve my shower pressure?
If your current shower is gravity-fed, a combi can significantly improve pressure, though this is limited by your home's incoming mains supply.
Can a combi run two showers?
High-output combis can often run two showers, but performance may drop if both are used simultaneously. An unvented cylinder is usually better for multi-bathroom homes.
Is an unvented cylinder better for multiple bathrooms?
Yes, because it stores a volume of hot water at mains pressure, it can supply multiple outlets simultaneously without the flow-rate drops typical of combi boilers.
How do I know if my mains water supply is good enough?
We perform a dynamic pressure and flow rate test during our assessment to determine exactly which systems are viable for your property.
What size unvented cylinder do I need?
This depends on the number of occupants and bathrooms. We calculate your peak demand to ensure you have consistent hot water for your needs.
Will my existing radiators be suitable?
Usually yes, but we assess their condition and age, as a conversion involves operating the system under increased pressure.
How long does a full heating-system conversion take?
While every home differs, conversions take longer than simple swaps. A more accurate timescale is provided following our technical survey.
What happens to my old tanks and cylinder?
We can remove all redundant equipment as part of the installation process, provided this is included in your agreed quotation.
Will you remove the redundant equipment?
Yes, professional removal and disposal of your old tanks, cylinders, and redundant pipework is a standard part of our conversion service.
