UK landlords searching for the best storage combi boilers need space-saving solutions that deliver strong hot water flow rates for multiple bathrooms or high-demand tenancies, combining combi convenience with integrated small-cylinder storage to reduce pressure drops and improve tenant satisfaction while supporting EPC improvements.
The 5 Best Storage Combi Boilers: At a Glance
The top storage combi boilers for landlords in 2026 feature integrated hot water stores, typically 40 to 60 litres, high flow rates above 18 l/min, A-rated condensing efficiency for EPC C compliance, extended warranties to limit repair risk in rentals, and reliable Gas Safe servicing networks. These models suit larger flats, family homes, or HMOs without needing a full separate cylinder.
| Model | Efficiency (ErP) | Typical Unit Cost | Installed Cost (approx.) | Warranty (accredited install) | Trustpilot Rating | Key Landlord Benefit |
| Viessmann Vitodens 111-W | Up to 98% | £1,700–£2,000 | £3,500–£4,500 | Up to 12 years | 4.6/5 | Highest efficiency & hot water store |
| Vaillant ecoTEC Plus 937 | 94% | £1,600–£1,900 | £3,400–£4,400 | Up to 10 years | 4.5/5 | Quiet operation & fast recharge |
| Baxi 800 Storage Combi | 94% | £1,400–£1,700 | £3,200–£4,100 | Up to 10 years | 4.4/5 | Good value & easy servicing |
| Ideal Logic+ Store Combi | 94% | £1,300–£1,600 | £3,100–£4,000 | Up to 12 years | 4.8/5 | Strong warranty & tenant-friendly |
| Alpha E-Tec Store Combi | 93% | £1,200–£1,500 | £3,000–£3,900 | Up to 10 years | 4.7/5 | Competitive price & corrosion resistance |
Notes: Prices are 2026 UK averages for 25 to 35kW storage combi models with around 46 litre integrated stores, suitable for 2 to 4 bathrooms. Installed costs include standard Gas Safe fitting and flue. All are wall-mounted A-rated condensing storage combi boilers. Actual output, store size, and costs vary by property.
Landlords upgrading heating in high-demand rental properties can request a new boiler quote for expert sizing advice, EPC compliance support, and professional installation. Staying familiar with Boiler pressure loss troubleshooting tips can also be worthwhile for maintaining optimal performance, since understanding common issues such as airlocks or pump failures helps address problems quickly before they escalate into something more disruptive for tenants.
1. Viessmann Vitodens 111-W
The Viessmann Vitodens 111-W leads the best storage combi boilers for landlords with its 46-litre integrated store delivering hot water performance equivalent to a 150-litre cylinder, alongside exceptional efficiency.
Specifications and features: 25 to 35kW output, a 46L stainless steel integrated store, an 18 l/min flow rate, MatriX-Plus burner and Lambda Pro combustion control, 20% hydrogen blend readiness, and a compact wall-mount design.
Efficiency: up to 98% seasonal efficiency with advanced condensing technology.
Boiler unit cost: £1,700 to £2,000. Installed cost: £3,500 to £4,500.
High modulation and efficiency deliver £150 or more in annual savings versus older combis, reducing tenant bills. It holds a 4.6/5 Trustpilot rating and is a Which? Recommended model for performance and longevity.
2. Vaillant ecoTEC Plus 937
The Vaillant ecoTEC Plus 937 excels among the best storage combi boilers for its quiet recharge cycles and reliable hot water delivery in multi-occupancy rentals.
Specifications and features: 30 to 37kW output, an integrated storage cylinder, high flow rates for simultaneous use, IoniDetect combustion monitoring, and vSMART app compatibility.
Efficiency: 94% ErP A-rated.
Boiler unit cost: £1,600 to £1,900. Installed cost: £3,400 to £4,400.
Efficient operation with low maintenance needs. It holds a 4.5/5 Trustpilot rating and is a frequent Which? Best Buy contender.
3. Baxi 800 Storage Combi
The Baxi 800 Storage Combi offers solid affordability in the best storage combi boilers range, ideal for landlords seeking reliable performance without premium pricing.
Specifications and features: 25 to 33kW output, an integrated store for improved flow, a stainless steel heat exchanger, and a compact footprint.
Efficiency: 94% ErP A-rated.
Boiler unit cost: £1,400 to £1,700. Installed cost: £3,200 to £4,100.
Competitive efficiency for everyday rental use, with a 4.4/5 Trustpilot rating.
4. Ideal Logic+ Store Combi
The Ideal Logic+ Store Combi provides excellent value and long warranties among the best storage combi boilers, appealing to cost-conscious landlords managing multiple properties. The wider Ideal Logic combi boiler features cover advanced energy efficiency technology in more depth, helping reduce utility bills while maintaining optimal heating performance, alongside a compact design that suits easy installation in small spaces.
Specifications and features: 25 to 35kW output, built-in storage for better hot water, front-access servicing, and a diagnostic display.
Efficiency: 94% ErP A-rated.
Boiler unit cost: £1,300 to £1,600. Installed cost: £3,100 to £4,000.
Good modulation reduces energy waste, with a 4.8/5 Trustpilot rating praised for value.
5. Alpha E-Tec Store Combi
The Alpha E-Tec Store Combi delivers budget-friendly hot water performance in the best storage combi boilers category, with strong corrosion resistance for long-term rental reliability.
Specifications and features: 25 to 33kW output, an integrated store, stainless steel components, and easy installation features.
Efficiency: 93% ErP A-rated.
Boiler unit cost: £1,200 to £1,500. Installed cost: £3,000 to £3,900.
Affordable to run with solid efficiency, and a 4.7/5 Trustpilot rating.
How to Choose the Best Storage Combi Boiler
Choosing the best storage combi boiler for a landlord’s rental property means balancing integrated store size against hot water demand, efficiency for EPC ratings, warranty length to minimise repairs during tenancies, and service network coverage.
Choose the Viessmann Vitodens 111-W if the highest efficiency and largest effective hot water output are needed for busy HMOs or family rentals.
Don’t choose Viessmann if budget is tight or local engineers have limited experience with the brand.
Choose the Vaillant ecoTEC Plus 937 if quiet operation and smart controls will boost tenant satisfaction in noise-sensitive properties.
Don’t choose Vaillant if the absolute longest warranty matters more than recharge speed.
Choose the Baxi 800 Storage Combi if reliable performance at a competitive price is wanted for a smaller rental portfolio.
Don’t choose Baxi if premium efficiency ratings are required for strict EPC compliance.
Choose the Ideal Logic+ Store Combi if extended warranties and straightforward maintenance are priorities.
Don’t choose Ideal if very high simultaneous flow rates are essential.
Choose the Alpha E-Tec Store Combi if the lowest upfront cost with decent storage performance matters most.
Don’t choose Alpha if the most established premium brands are preferred.
Other Boiler Guides Worth Considering
Storage combi boilers are one option among several worth weighing up depending on a property’s specific hot water demand.
For a smaller property where a full storage combi is not needed, best combi boilers for small homes covers compact standard combi options instead, while best 40kw combi boilers for efficiency is worth comparing for a property with high simultaneous demand that a standard storage combi still might not fully cover.
Need a New Boiler Quote?
Upgrading to one of the best storage combi boilers helps landlords provide reliable, high-flow hot water in rentals, improve EPC scores, and reduce complaints. Requesting a new boiler quote is a good next step for tailored advice, transparent pricing, and accredited Gas Safe installation. It is also worth reviewing the wider set of top boilers for rental properties to balance efficiency and cost-effectiveness across a portfolio, since modern boilers can both enhance tenant satisfaction and improve profitability through lower energy costs. Any installation should be carried out by an engineer listed on the Gas Safe Register.
FAQs
Are storage combi boilers suitable for properties with very high simultaneous hot water demand?
Yes, the integrated store provides a buffer for multiple showers or taps, but an extremely high-demand HMO may still benefit from a separate system boiler and larger cylinder instead.
How do storage combi boilers impact EPC ratings compared with standard combis?
The higher effective hot water efficiency often improves SAP calculations and EPC scores by one to three bands, helping landlords meet the 2030 EPC C minimum more easily.
Are storage combi boilers hydrogen-ready for future rental compliance?
Many top models, such as the Viessmann Vitodens 111-W, are 20% hydrogen blend ready, offering landlords a low-disruption route to lower carbon emissions as the gas grid evolves.
What are the typical servicing requirements for storage combi boilers in rented properties?
Annual Gas Safe checks are mandatory, and the integrated store adds only minimal extra maintenance, though it does need periodic checks for scale and pressure to keep performing at its rated output.
Can landlords deduct storage combi boiler costs as tax expenses?
Yes, replacement boilers generally qualify as revenue repairs, deductible against rental income, while efficiency upgrades may also access enhanced capital allowances or grants. It is worth checking current guidance or consulting an accountant for a specific property’s situation.
How does the integrated store affect the physical size of these boilers compared with a standard combi?
Storage combi boilers are noticeably larger and heavier than a standard combi of the same output, due to the built-in cylinder, so it is worth confirming the unit will fit the intended cupboard or utility space before committing to a specific model, particularly in a smaller flat.
Do storage combi boilers cost more to run than a standard combi of the same output?
Running costs are broadly comparable, since both are A-rated condensing units, though the storage combi’s integrated cylinder does lose a small amount of standing heat over time. In practice, this is generally offset by more consistent, efficient operation during peak demand, when a standard combi might otherwise struggle to keep up.
I’m Penny North, a home energy heating expert. My mission is to demystify new boilers and complex heating systems to help you achieve a warm, cosy home with lower energy bills and a smaller environmental footprint.