A residential heat pump water heater works by extracting heat energy from the surrounding air and using it to heat your home's water supply rather than generating heat from scratch the way a gas boiler or immersion heater does. Because it moves heat rather than creates it, a modern heat pump hot water system delivers up to 4 units of heat energy for every 1 unit of electricity consumed. That translates to a Seasonal Coefficient of Performance (SCOP) of up to 4.5, making it three to four times more energy-efficient than a standard electric immersion heater.
For a UK household of four, switching from a gas combi boiler to a Sailax heat pump water heater typically reduces hot water heating costs by £350 to £800 per year - depending on existing tariff rates and daily usage. The savings increase further if you pair the system with a solar PV array or a time-of-use electricity tariff such as Octopus Go, which allows off-peak heating at reduced rates overnight.
The UK Government's Boiler Upgrade Scheme (BUS) offers homeowners a grant of up to £7,500 to replace fossil fuel heating systems with low-carbon alternatives, including heat pump water heaters.
The grant is paid directly to your installer and deducted from the installation cost - you do not need to apply separately or wait for reimbursement.
Lower your energy bills without compromising comfort. Spend less, enjoy more every season.
Claim your Boiler Upgrade Scheme grant. No red tape. No waiting.
Adapts to freezing winters and muggy summers so you stay comfortable, always.
Up to 400% output that’s 4x the heat for each unit of electricity.
Built to last, ready for tomorrow. Our product keeps your home ahead of rising energy costs and evolving climate needs.
Shrink your carbon footprint while you slash your bills. It is better for the planet and your pocket.
From consultation to switch-on Sailax handles it all, stress-free.
Choosing the right capacity is straightforward - the primary factor is the number of occupants in your home and your typical daily hot water demand. Sailax offers the Ecogen290, a 300-litre all-in-one unit suited to households of 1 to 7 people.
The table below outlines typical sizing guidance:
| Household Size | Tank capacity | Best suited to |
|---|---|---|
| 1–2 people | 200 L | Suitable for flats, bungalows, compact homes |
| 2–4 people | 250 L | Standard family home, average daily usage |
| 4–7 people | 300 L (Ecogen290) | Larger homes, higher peak demand |
| 7+ people | Commercial range | See sailax.co.uk/commercial-heat-pump-water-heater |
If your household has high simultaneous demand for example, two showers running at the same time our installation team will factor this into the survey and recommend whether a larger tank or a supplementary immersion element is appropriate.
Honestly didn’t expect to notice such a big difference—our energy bill dropped within the first month! The installation was smooth, the system’s quiet, and the house feels cosy all day. Wish we’d switched sooner.
Priya & James M., London
The Ecogen290 is Sailax's flagship residential heat pump water heater. Key technical specifications:
| Specification | Value | Notes |
|---|---|---|
| Refrigerant | R290 (propane) | Zero ozone depletion potential, low global warming potential (GWP: 3) |
| Tank capacity | 300 litres | All-in-one integrated tank and heat pump |
| SCOP | Up to 4.5 | At A+++ efficiency rating under UK test conditions |
| Operating temp range | -5°C to +35°C ambient | Designed and tested for UK climate conditions |
| Noise level | < 48 dB(A) | Quieter than a standard dishwasher |
| Water temperature | Up to 65°C | Legionella control cycle built-in |
| BUS eligibility | Yes | MCS product listing confirmed |
| Warranty | 5 years (parts & labour) | Extended warranty available on request |
| Dimensions (H x W x D) | 1,850 x 600 x 600 mm | Suitable for utility rooms, garages, outbuildings |
| Weight (full) | Approx. 300 kg | Ground floor installation recommended |
The Ecogen290 achieves a SCOP of up to 4.5 under UK-standard conditions, meaning every £1 of electricity input returns up to £4.50 worth of heat. This is independently verified under EN 16147 test methodology - the same standard used by all MCS-certified products.
Unlike some imported heat pump models designed for warmer European climates, the Ecogen290 is tested and rated for operation in ambient temperatures as low as -5°C covering the vast majority of UK winter conditions, including Scotland. Performance does reduce below -5°C, and our installation team will advise on supplementary heating options if your property is in a particularly exposed location.
Sailax installations are carried out by MCS-certified engineers - a legal requirement for BUS grant eligibility. From your initial home survey to commissioning, the process typically takes one day. We handle all grant paperwork, building regulations notification, and post-installation commissioning checks. Most customers are using their new system within 24 hours of installation.
| Gas boiler | Sailax heat pump water heater |
|---|---|
| Running costs | Running costs |
| Higher — gas price per kWh typically lower, but efficiency is ~90% | Lower long-term — higher electricity cost offset by 300–400% efficiency |
| Carbon emissions | Carbon emissions |
| High — gas produces around 200g CO2 per kWh | Up to 75% lower when powered by grid electricity (UK grid increasingly renewable) |
| Government grant | Government grant |
| None available for new gas boiler installations | Up to £7,500 via Boiler Upgrade Scheme |
| Future-proofing | Future-proofing |
| Gas boiler sales banned in new builds; phase-out roadmap ongoing | Eligible for all current and proposed green energy incentives |
| Maintenance | Maintenance |
| Annual service required, ~£80–150/year | Minimal — annual visual check, no combustion components |
| Lifespan | Lifespan |
| 10–15 years typical | 15–20 years typical |
Yes - for most UK homeowners, a residential heat pump water heater is one of the most cost-effective renewable energy upgrades available. With the Boiler Upgrade Scheme grant of up to £7,500 offsetting the installation cost, and annual energy savings of £350 to £800 depending on your current system, many Sailax customers achieve full payback within 3 years. The system then operates at net gain for its remaining 15–20 year lifespan. Rising gas prices and the UK's long-term gas phase-out roadmap mean the financial advantage of switching is likely to increase over time.
Sailax specialises exclusively in heat pump water heaters - it is not a broad heating company offering every product type. This focus means our engineers carry deeper product knowledge and our MCS certification covers the specific models we install, including the Ecogen290. We manage the entire process: survey, BUS grant application, installation, commissioning, and aftercare. Our installations comply with all current UK building regulations and MCS standards.
Typical annual savings for a UK household switching from gas central heating to a Sailax heat pump hot water system range from £350 to £800 per year. The exact figure depends on your current energy tariff, hot water usage, household size, and whether you use time-of-use electricity pricing. Sailax provides a personalised savings estimate as part of your free home survey - based on your actual current bills, not industry averages.
For households of 1 to 7 people, the Sailax Ecogen290 (300 litres) covers the full range of residential demand. As a rule of thumb, allow 40–50 litres of hot water capacity per person per day. Your Sailax engineer will confirm the correct sizing during your free home survey, taking into account peak simultaneous demand and your property's hot water draw profile.
Yes. The Ecogen290 is designed as a direct replacement for gas combination boilers, oil boilers, electric immersion heaters, and LPG systems. The installation requires a connection to your cold water mains supply and adequate space in a utility room, garage, or outbuilding (minimum 10m3 of free air volume around the unit for efficient operation). Your Sailax engineer will assess suitability during the survey and flag any preparatory work required, such as upgrading pipework or improving ventilation.
The vast majority of UK homes are suitable. The main requirements are adequate space for the unit (the Ecogen290 is 1,850mm tall and 600mm in diameter) and sufficient air volume around it for the heat pump to operate typically a utility room or garage of at least 10m3. Flats with no access to external or utility spaces may require an alternative configuration. Properties in Scotland and northern England are fully supported - the Ecogen290 operates efficiently in ambient temperatures as low as -5°C, which covers typical UK winter lows.
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