Hot Water Cylinder Solutions
The right hot water cylinder is essential for any heating system, particularly when paired with a heat pump. Standard boiler cylinders are not compatible with heat pumps — heat pump cylinders need an enlarged coil (minimum 1.5m², ideally up to 6m²) for efficient heat transfer, a 3kW immersion backup for legionella pasteurisation at 60°C+, and a minimum capacity of 200 litres. We supply and install a range of cylinders: the Mixergy smart cylinder (which heats only the water you need, absorbs surplus solar, and integrates with Octopus tariffs); the Megaflo Eco (the UK industry benchmark for mains-pressure hot water with a lifetime warranty on premium models); and the Telford Tempest (outstanding value with a lifetime warranty). All unvented cylinder installations are carried out by our G3-qualified engineers as required by Building Regulations.
Key Benefits
Benefits of a New Cylinder
Heat Pump Compatible
Specialist cylinders with enlarged coils (min 1.5m², up to 6m²) ensure efficient heat transfer from the low-temperature output of a heat pump. Standard cylinders waste energy.
Mains Pressure Hot Water
Unvented cylinders deliver powerful, mains-pressure hot water to all taps and showers simultaneously — no pump required, no cold storage tank in the loft.
Smart Technology
The Mixergy cylinder's patented top-down heating delivers hot water from just 10% charge in under 20 minutes, and its AI learning algorithm reduces energy use by up to 40%.
Solar Divert Compatible
Both the Mixergy (built-in) and Megaflo (via myenergi Eddi at ~£400) can absorb surplus solar generation to heat water — far cheaper than solar thermal (£3,000–£5,000).
G3 Qualified Installation
Our engineers hold G3 certification for unvented hot water systems, legally required by Building Regulations. Always verify this before allowing any installer to work on an unvented system.
Long Warranties
Megaflo: 25-year tank warranty. Mixergy: 25-year cylinder warranty. Telford Tempest: lifetime warranty. All significantly outlast standard vented cylinders.
Our Process
How It Works
Free Survey
We visit your property to assess your heating needs, measure heat loss, and discuss the best options for your home.
Design & Quote
We design a bespoke system, identify all eligible grants including the £7,500 BUS scheme, and provide a transparent fixed-price quote.
Installation
Our MCS certified engineers install your system cleanly and efficiently, typically within 2–4 days, with minimal disruption to your home.
Aftercare
Full system handover, MCS certification, warranty registration, BUS grant application completion, and ongoing support when you need it.
Hot Water Cylinder Costs
A vented hot water cylinder replacement costs £150–£400 for the unit plus installation. Unvented (Megaflo-type) systems cost £800–£1,500 for the unit plus £400–£700 installation. Heat pump-compatible cylinders with oversized coils cost £800–£1,500 installed. The Mixergy smart cylinder is £1,200–£2,000+ installed and is our premium recommendation for solar panel owners. The Telford Tempest offers outstanding value at £300–£700 for the unit. When installed as part of a heat pump system, the cylinder cost is included in the overall heat pump package price. G3-qualified installation is a legal requirement for all unvented systems.
Trusted Partners
Brands We Install
What We Install
Products We Use
We only install products we trust. Click any product below to see full specifications and why we recommend it.
Areas We Cover for Hot Water
We install hot water across Cornwall. Click your area for local information and a free quote.
Pair Your Hot Water with Another Service
Many of our customers save more by combining services. Here's what works best with a Hot Water.
Pair Your New Cylinder with a Heat Pump
A new heat pump-compatible cylinder is the ideal foundation for a full heat pump installation. If you're replacing your cylinder now, it's the perfect time to plan your switch — the £7,500 BUS grant covers much of the cost.
Heat Your Water with Free Solar Power
Adding an immersion diverter to your new cylinder means surplus solar electricity heats your water instead of being exported for a few pence per unit. Effectively free hot water on sunny days.
Want a bundled quote for multiple services? Contact us for a combined survey.
Our Work
Recent Hot Water Projects
Real installations by our team across Cornwall — challenge, solution, and outcome.
Common Questions
Frequently Asked Questions
01 What is a hot water cylinder and do I need one?
02 How much does a new hot water cylinder cost?
03 What size hot water cylinder do I need?
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