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30kW Combi Boilers – Everything You Need to Know

Live in a medium-sized home with one bathroom and need a new combi boiler? A 30kW combi boiler could be a good option for your home. 

Combi boilers are available in various sizes and from every boiler brand out there, making the selection process confusing and daunting. We know that choosing the right combi boiler for your home is not an easy task, and whilst we always recommend you consult a heating engineer, it’s worth having an idea of what size boiler will best fit your requirements.

This article covers what you need to know about 30kW combi boilers, including costs and the available models, to help you decide on the perfect boiler for your home. 

What is a combi boiler?

A combi boiler requires very little space in your home because it doesn’t need separate tanks or cylinders for storing water. It’s a water heater and a central heating boiler system in a single compact unit that works by taking water directly from the mains and heating it on demand. That means a combi boiler will only heat water when you need it.

Because a combi boiler doesn’t store hot water in a cylinder, like a system or regular boiler, it can provide an unlimited supply of hot water with no waiting time. Combi boilers are the most popular type sold in the UK but can struggle to provide enough hot water to run more than one tap or shower at a time. 

Is a 30kW combi boiler suitable for my home?

First, you need to determine whether you need a 30kW combi boiler. A combi boiler with a 30kW output is usually suitable for three-bedroom homes with one main bathroom, up to 12 radiators and possibly an en-suite bathroom. 

Boiler size is measured by its output in kilowatts (kW), and the more heating and hot water you need, the higher the kW will need to be to meet your demands. But you must be careful when choosing the correct size boiler for your home. If you oversize a combi boiler, you will waste energy and spend more money on your bills. And when you undersize, your boiler won’t heat your home property or produce enough hot water.  

If you’re unsure whether a 30kW combi boiler is suitable for your home, you can contact a trusted Gas Safe registered engineer for advice. 

30kW combi boilers you can buy right now

If your heating engineer recommends a 30kW combi for your home, they may give you some advice on the best boiler brands and models on the market. Many boiler brands make 30kW combi boilers, such as Ideal, Vaillant and Worcester Bosch. 

But with so many brands available, how do you know which one to choose? We’re now going to look at some of the 30kW combi boilers you can buy right now.

Worcester Bosch Greenstar 4000 Combi

Worcester Bosch is one of the most trusted boiler brands in the UK, and the Greenstar 4000 combi boiler takes some beating. Available with a 30kW output, this boiler delivers a hot water flow rate of 10.8 litres per minute and a wide power range to help reduce gas consumption whilst meeting all your heating and hot water needs. The Greenstar 4000 keeps the much-loved features of the best-selling Greenstar i boiler and includes improvements to its performance and appearance. 

Other benefits and features include:

  • One of Worcester Bosch’s quietest combi boilers to date
  • Easy-to-use full-colour text display
  • Innovative ‘Quick Tap’ water-saving function  
  • Compatible with the wireless Bosch EasyControl that connects to your smartphone and allows you to control your heating and hot water from anywhere
  • Up to a 10-year warranty when installed by a Worcester Bosch Accredited installer

Worcester Bosch Greenstar 2000 Combi

The Greenstar 2000 Combi from Worcester Bosch is a price-competitive boiler available in two outputs, including 30kW, and delivers a hot water flow rate of 10.8 litres per minute. It can fit between standard-sized wall-mounted kitchen cupboards, is quick to install, and includes removable side panels for easy access to the internal components. 

Other benefits and features include:

  • Worcester Bosch’s quietest combi boiler to date
  • Innovative ‘Quick Tap’ water-saving function  
  • Compatible with the wireless Bosch EasyControl that connects to your smartphone and allows you to control your heating and hot water from anywhere
  • 5-year warranty as standard
  • 6-year warranty when installed with a Greenstar system filter

Viessmann Vitodens 200-W Combi

Viessmann’s Vitodens 200-W 30kW Combi is a wall-mounted gas condensing boiler that delivers a hot water flow rate of 15.7 litres per minute. This boiler is easy to install, operate and maintain, plus it has compact dimensions (only 450mm wide) and comes complete with an Inox-Radial heat exchanger. German manufacturer Viessmann is one of the most respected boiler brands on the market today and scores top marks in terms of quality and reliability. 

Other benefits and features include:

  • Quiet operation thanks to low fan speed and high-efficiency internal pump
  • 7-inch colour touchscreen with outdoor weather sensor
  • Control your heating system from your smartphone using the ViCare app
  • Environmentally friendly MatriX-Plus burner – greater efficiency
  • 3-year warranty as standard
  • Option to extend the warranty to 10 or 12 years (additional fee applies)

Vaillant ecoTEC Pro Combi

The ecoTEC Pro 30kW Combi is a compact and quiet combi boiler from Vaillant, a popular boiler brand that often scores strongly amongst consumers for customer satisfaction. Hand-built in Vaillant’s awarding-winning manufacturing plant in the UK, this boiler delivers a hot water flow rate of 12.3 litres per minute, is small enough to fit almost anywhere within your home and comes complete with a bright and easy-to-use display.

Other benefits and features include:

  • Quality German design and engineering
  • Quiet Mark approved – performs quietly
  • Stainless steel heat exchanger – superior heat transfer and highly efficient performance
  • Compact and lightweight – exceptional siting flexibility
  • Compatible with Vaillant’s vSMART app-based control for heating on the go
  • 2-year warranty as standard
  • 7 to 10 year-warranty available when installed by a Vaillant Advance installer

Ideal Logic Plus Combi

The Logic Plus 30kW Combi is an award-winning boiler and an Energy Saving Trust endorsed product from Ideal, a brand known for manufacturing reliable and cost-friendly boilers. Made here in the UK, this boiler delivers a hot water flow rate of 12.4 litres per minute, is small enough to fit inside a standard kitchen cupboard, and comes complete with a 10-year warranty on the heat exchanger for peace of mind. 

Other benefits and features include:

  • Quiet Mark approved – performs quietly
  • Built-in frost protection
  • LPG conversion available 
  • Easy-to-use fully backlit LCD display
  • 7-year warranty as standard

Baxi 600 Combi

Baxi is another boiler brand with a good reputation for manufacturing reliable and affordable boilers, and the Baxi 600 30kW Combi is no exception. Made in the UK using top quality brass components, this boiler is compact yet powerful and delivers a hot water flow rate of 12.2 litres per minute. It features a simple hanging bracket, an OpenTerm interface and an Easy-Fill permanent filling link so that you can top up your system with ease.

Other benefits and features include:

  • Compact kitchen cupboard fit
  • Pipes stay hidden behind the boiler within its casing
  • Simple hanging bracket
  • Choice of flue lengths 
  • Compatible with the Baxi uSense smart room thermostat and app – control your heating from your phone 
  • 7-year warranty as standard

How much do these 30kW combi boilers cost?

The table below shows you the typical price of the 30kW combi boilers we mentioned above. Please be aware that the prices in the table do not include installation costs. 

30kW Combi BoilerTypical Price
Worcester Bosch Greenstar 4000 Combi£1,050
Worcester Bosch Greenstar 2000 Combi£852
Viessmann Vitodens 200-W Combi£1,220
Vaillant ecoTEC Pro Combi£1,810
Ideal Logic Plus Combi£966
Baxi 600 Combi£850

Getting a Gas Safe registered engineer to carry out the installation will cost you between £500 and £1,000. That said, the cost of boiler installation can vary depending on where you live, who you choose to do the job, and how much work is required. 

If you get a straightforward replacement combi boiler and want to keep it in the same position as your existing one, you can expect to pay less than if you were to install a new one in a different location. You can also expect to pay more when changing the boiler type, so if you move from a system or heat-only boiler to a 30kW combi boiler.  

The best way to save money on the cost of a new 30kW combi boiler and the installation is to shop around and compare quotes. Thankfully, we make comparing quotes easy. All you need to do is complete our online form to get free quotes from Gas Safe registered engineers in your local area