If you own a holiday home, static caravan, lodge, or any off-grid property in the UK, the Ariston E-Combi ONE is probably the most talked-about boiler on the market right now — and for good reason. It is compact, LPG-ready straight out of the box, includes the horizontal flue kit at no extra cost, and delivers the kind of hot water performance and heating reliability that leisure properties genuinely need. All backed by Ariston's 5-year warranty and dedicated UK technical service.
In this guide, we explain exactly what the E-Combi ONE is, why it has become the default replacement boiler for thousands of holiday homes and static caravans across the UK, how to install it, and how the included LPG conversion kit works. Whether you are upgrading an old Morco, replacing a tired Worcester Bosch, or fitting a boiler into a new lodge from scratch — this is the page you need to read first.
"The Ariston E-Combi ONE is sold with the LPG conversion kit already in the box. Your Gas Safe engineer can complete the changeover in minutes — no extra parts to order, no waiting, no additional cost."
What Is the Ariston E-Combi ONE?
The Ariston E-Combi ONE is a wall-hung condensing combi boiler that provides both central heating and instant mains-pressure domestic hot water from a single, compact unit. There is no separate hot water cylinder required — the boiler heats water on demand as you open a tap or shower.
It is available in two outputs — 24kW and 30kW — and is sold at AIZO Quality Heating as a complete package that includes the Ariston Standard Horizontal Flue Kit (Part No. 3318073) and the LPG conversion kit, both at no extra charge. This is the package that makes it such remarkable value for off-grid properties.
E-Combi ONE 24 — SKU 3301445
22kW CH output · 10.4 L/min DHW
Ideal for 1–3 bed holiday homes & caravans
E-Combi ONE 30 — SKU 3301132
28kW CH output · 12.5 L/min DHW
Ideal for larger lodges with 2+ bathrooms
At the heart of both models is Ariston's patented Xtratech™ stainless steel heat exchanger — a single-coil design with 142% wider waterways than previous generations. Wider channels reduce debris blockages, lower pressure drops, and increase the condensing surface area for improved thermal efficiency. The exchanger is TUV Rheinland certified and resists corrosion across a wide pH range.
The unique AUTO function continuously monitors the building's thermal demand and modulates the burner output between minimum and maximum — typically a 1:7 ratio — rather than simply cycling on and off. This reduces wear, improves seasonal efficiency, and keeps the boiler in condensing mode for longer, where efficiency reaches approximately 99% at 30% load.
Why Holiday Homes and Static Caravans Love the E-Combi ONE
The Ariston E-Combi ONE has become the dominant replacement boiler across the UK's holiday home and static caravan sector. Speak to any engineer who services park homes, lodges, or static caravans and you will hear the same name. Here is why.
No Mains Gas Required
Holiday parks, static caravan sites, rural lodges, and off-grid properties rarely have access to the mains gas network. The E-Combi ONE runs on LPG — either from bulk tanks supplied by your gas provider or standard propane bottles — with the conversion kit already included in the box.
Compact Dimensions — Fits Where Others Don't
At 735 × 400 × 299 mm and weighing just 31.9 kg (30kW), the E-Combi ONE fits neatly into standard kitchen cupboards, utility rooms, and airing cupboards typical of holiday lodges and park homes. Minimum side clearances are just 5 mm.
Direct Drop-In Replacement
All pipework connections sit in the same positions as the previous Ariston E-Combi range and many older caravan boilers. Engineers frequently achieve like-for-like swaps without any pipework modification, cutting installation time and cost significantly.
Quiet Enough for an Open-Plan Living Space
Operating at around 49 dB, the E-Combi ONE is quieter than a standard conversation. For open-plan holiday homes where the boiler cupboard is close to living areas, that level of noise is genuinely unobtrusive.
IPX5D Splash Protection
The E-Combi ONE carries an IPX5D electrical protection rating — protected against water jets from any direction. This gives installers more flexibility for siting in kitchen or bathroom-adjacent spaces, which is often relevant in compact caravan layouts.
Smart Control When You Need It
The boiler is Ariston NET ready. Add the optional NET Wi-Fi adapter and you can monitor and control heating remotely via smartphone — ideal if you manage your holiday property from a distance and want to pre-heat it before guests arrive.
Horizontal Flue: The Most Common Installation Method
The vast majority of Ariston E-Combi ONE installations in holiday homes and static caravans use horizontal flueing — and this is precisely why Ariston includes the horizontal flue kit as standard. In a balanced horizontal flue setup, the boiler draws fresh air in and expels combustion gases out through the same 60/100 mm coaxial duct, straight through an external wall behind the boiler.
This configuration is almost always the preferred choice in leisure properties because:
- Speed — a straight horizontal run through a single external wall is the fastest installation path. No roof penetrations, no additional terminal fittings.
- Cost — fewer components, shorter labour time. The flue kit is already in the box, so there is nothing extra to source or pay for.
- Structure — holiday lodges and static caravans typically have a relatively thin external wall with easy access, making a 60/100 mm coaxial bore straightforward.
- Regulations — a through-wall balanced flue is fully room-sealed and complies with Building Regulations Document J without additional complexity.
The included flue kit covers a standard straight-through installation. Extension kits and elbow adapters are available separately for longer runs or non-standard configurations.
The LPG Conversion Kit: Everything You Need, Already in the Box
One of the most practical features of the Ariston E-Combi ONE package at AIZO Quality Heating is that the LPG conversion kit is included as standard — no additional purchase required. Most holiday home properties and static caravan sites are not connected to the mains gas grid and rely on LPG, either from bulk storage tanks supplied by a gas company or from standard propane (G31) bottles.
The E-Combi ONE ships factory-set for Natural Gas (G20). Converting it to LPG (G31) is a straightforward procedure carried out by a Gas Safe registered engineer and takes approximately 30–45 minutes on-site.
What the Conversion Involves
- Replacing the burner injectors — LPG requires smaller jet orifices than natural gas because it burns at a higher calorific value. The conversion kit contains the correct LPG-rated jets.
- Adjusting the gas valve — the gas valve inlet and outlet pressures are reset to the correct LPG operating pressures as specified in the installation manual.
- Confirming the conversion in the boiler's software — a simple parameter change in the boiler's service mode tells the control board which gas type is in use.
- Combustion analysis check — the engineer uses a flue gas analyser to verify CO₂ and CO levels are within specification, confirming safe and efficient combustion on LPG.
The LPG conversion must be carried out by a Gas Safe registered engineer. The procedure is quick but legally must not be performed by an unqualified person. Always ensure the installer completes the benchmark commissioning checklist — this is required to activate the extended warranty.
How to Install the Ariston E-Combi ONE: Step by Step
The E-Combi ONE is widely praised by installers for its straightforward fit. Colour-coded pipework connections, a lightweight chassis, and same-position connections as previous Ariston models make it one of the easiest combi boilers to commission. Here is the standard installation sequence for a horizontal flue setup.
Fix the Wall Bracket
Hang the boiler's installation template on the wall and mark the bracket fixing points. The bracket is pre-fitted — attach to solid masonry or timber noggins, ensuring it is level. Allow minimum clearances: 300 mm above, 250 mm below, and just 5 mm each side.
Core the Flue Hole & Fit the Flue
Using the flue template supplied, core through the external wall at the correct diameter (typically 107 mm for the 60/100 mm coaxial system). Insert the wall liner, then slide the flue through from inside and connect to the boiler's top flue outlet. Trim the outer terminal flush with the wall.
Connect the Colour-Coded Pipework
The E-Combi ONE uses colour-coded connection ports to minimise installation errors: CH flow (red), CH return (blue), gas (yellow), DHW outlet, and cold water inlet. All connections are in the standard Ariston positions, enabling a direct retrofit without modifying existing pipework.
Electrical Connection & Room Thermostat
Connect the 230V / 50Hz mains supply to the boiler's terminal block. Wire the room thermostat or Ariston NET adapter if using smart controls. The E-Combi ONE includes a built-in 24-hour mechanical clock, so basic time programming works with no additional wiring if preferred.
LPG Conversion (If Applicable)
If installing on LPG, carry out the conversion using the kit supplied in the box. Replace the gas injectors with the LPG jets, set the gas valve pressures to the LPG specification, and update the boiler's service mode parameter. Conduct a full combustion analysis.
Commission & Complete Benchmark
Fill and pressurise the system (1–1.5 bar cold), purge air from the radiators, and carry out a full gas tightness test. Run the boiler through its ignition sequence, check all functions, and complete the Benchmark Commissioning Checklist. Hand this to the property owner — it is required to activate the 5-year warranty.
5-Year Warranty & Ariston UK Technical Service
Every Ariston E-Combi ONE comes with a 2-year manufacturer's warranty as standard. Register your boiler on the Ariston website within 30 days of installation and this extends automatically to 5 years — one of the longer warranty periods available on a gas combi boiler at this price point.
Ariston UK Technical Support
Ariston Thermo UK Ltd is headquartered in Milton Keynes with a national network of registered service engineers and a dedicated UK technical helpline. Spare parts are widely stocked at plumbing merchants including Screwfix and Plumbase, so waiting times for components are typically short.
What the Warranty Covers
The 5-year extended warranty covers boiler component failures under normal operating conditions. To maintain it, annual servicing by a Gas Safe registered engineer is recommended. Keep the benchmark checklist as proof of correct commissioning.
24kW vs 30kW: Which Model Do You Need?
Both models use the same Xtratech™ heat exchanger, the same AUTO function, and come with the same horizontal flue and LPG conversion kit. The key difference is output — which determines how many radiators the boiler can support and how fast it can deliver domestic hot water simultaneously.
| Specification | E-Combi ONE 24kW | E-Combi ONE 30kW |
|---|---|---|
| Product Code | 3301445 | 3301132 |
| DHW Output | 24 kW | 30 kW |
| CH Output | 22 kW | 28 kW |
| Hot Water Flow Rate (ΔT35°C) | ~10.4 L/min | 12.5 L/min |
| ErP Rating | A Rated ✓ | A Rated ✓ |
| Xtratech™ Heat Exchanger | ✓ Included | ✓ Included |
| AUTO Function | ✓ Yes | ✓ Yes |
| Horizontal Flue Kit | ✓ Included | ✓ Included |
| LPG Conversion Kit | ✓ Included | ✓ Included |
| Modulation Ratio | 1:7 | 1:7 |
| Expansion Vessel | 8 L built-in | 8 L built-in |
| Electrical Protection | IPX5D | IPX5D |
| Ariston NET Ready | ✓ Yes | ✓ Yes |
| Warranty | 2yr standard / 5yr on registration | 2yr standard / 5yr on registration |
| Recommended For | 1–3 bed holiday homes, single bathroom caravans | Larger lodges, 2+ bathrooms, higher demand |
See Inside the Ariston E-Combi ONE
This detailed walkthrough takes you inside the E-Combi ONE casing — a full strip-down and review covering the Xtratech™ heat exchanger, burner assembly, and key service points. Essential viewing before your first installation or service.
▶ Watch on YouTube — Inside the Ariston E-Combi ONE
Shop the Ariston E-Combi ONE Range
Both packages are available now at AIZO Quality Heating with express UK delivery. Each includes the horizontal flue kit and LPG conversion kit — everything a Gas Safe engineer needs for a complete installation.
Ariston
E-Combi ONE 24kW — with Horizontal Flue & LPG Kit
The 24kW model is the ideal fit for 1–3 bedroom holiday homes, single-bathroom static caravans, and park lodges. Delivers up to 10.4 L/min of domestic hot water on demand, with Xtratech™ heat exchanger, AUTO function, and ErP A efficiency rating. Includes horizontal flue kit (3318073) and LPG conversion kit.
Ariston
E-Combi ONE 30kW — with Horizontal Flue & LPG Kit
The 30kW model is designed for larger lodges and holiday homes with 2 or more bathrooms or higher simultaneous hot water demand. Produces up to 12.5 L/min of DHW at 35°C temperature rise — enough for a power shower and basin tap running together — with 28 kW central heating output.
£690.00 Inc. VAT
£575.00 exc. VAT — Free express UK delivery — Save 8%
Frequently Asked Questions
Does the E-Combi ONE really include the LPG kit at no extra cost?
Can it replace my old Morco or Worcester Bosch caravan boiler?
How do I get the 5-year warranty?
Which size should I choose for my holiday home?
Can the boiler be controlled remotely via a smartphone?
Is horizontal flueing suitable for all caravan and lodge installations?
Related Guides & Products
Looking to complete your heating system? These resources from AIZO Quality Heating will help:
- BTU Calculator — Work out the correct boiler output for your property before you buy.
- Boiler Flues & Accessories — Extension kits, elbows, and terminal guards for non-standard flue runs.
- Smart Thermostats — Pair your E-Combi ONE with a smart thermostat for remote holiday home control.
- Gas Combi Boilers — Browse the full range of combi boilers available at AIZO Quality Heating.
- Radiators & Heaters — Designer and traditional radiators to complete your heating system.
- Boiler Components — Inhibitors, scale filters, expansion vessels, and system accessories.
Ready to Order? Get the Complete E-Combi ONE Package
Every package includes the horizontal flue kit and LPG conversion kit — everything your Gas Safe engineer needs on the day. Free express UK delivery on most orders, with Klarna pay-in-3 available at checkout.
Shop 30kW — £690 Inc. VAT Browse All Combi Boilers