Is a Combi Boiler Cheaper to Run?

When it comes to heating your home and providing hot water, combi-boilers (short for combination boilers) are one of the most popular choices in the UK and beyond. Their space-saving, compact design and on-demand hot water abilities make them a go-to option for many households seeking a practical alternative to traditional boilers. But the big question remains: is a combi-boiler cheaper to run than other boilers?

In this blog post, we’ll break down the factors determining a combi-boiler’s running costs and help you decide if itis the most cost-effective option for your home.

How Does a Combi-Boiler Work?

A combi-boiler combines two functions in one unit: heating your home and providing hot water. The combi-boiler offers more practical and minimalist functionalities making it more appealing to some households than traditional or system boilers.

Households with traditional boiler systems usually operate with the use of a separate water tank or cylinder, whereas a combi-boiler heats water directly from the mains. This means that the comb-boiler provides hot water on demand without the need to wait for a tank to fill up. This helps save not only space but time waiting for the tap to warm up or the house to warm up.

Factors That Influence Running Costs

The question of determining running costs for any boiler system depends on various factors. This includes not only influenced by the type of boiler system but also how it is used within the household.

Energy Efficiency

Combi-boilers are a popular option for households as they are designed to be highly efficient, often with energy ratings of 90% or higher. Their unique system means they convert most of the fuel they use into heat, reducing energy wastage, providing hot water and heating using less fuel and lowering energy bills.

Most combi boilers are condensing boilers, which recycle heat from exhaust gases, improving efficiency further.

Usage Patterns

A combi-boiler can be cheaper to run if your household has low to moderate hot water demands. Since it heats water on demand, there’s no energy wasted keeping a tank of water hot. However, in larger homes with multiple bathrooms or high simultaneous hot water usage, a combi boiler may struggle to keep up with the demand, and running costs could increase. Usage patterns are one of the most important factors to consider when exploring the idea of a boiler conversion.

No Need for Storage

Due to there being no need for a hot water tank or cold-water storage cistern, a combi boiler avoids the heat losses associated with stored water in other boiler systems. This can take longer to reheat the water and use more energy, costing you more on your energy bills.

Type of Fuel

The type of fuel your boiler uses—gas, oil, or electricity—also plays a significant role in running costs. Gas-fired combi boilers are generally cheaper to run than electric boilers, given the lower cost of gas per unit of energy.

How Does the Combi-Boiler Compare to Other Boilers?

If your main goal with a new boiler is to reduce energy spending, then it’s good to compare other boiler systems with combi-boilers to understand their key differences.

Combi Boiler

System Boiler

Combi Boiler

Runs water from the mains
Immediate hot water and heating
Cost effective for smaller households

System Boiler

Store hot water in a cylinder
Requires more room and longer to heat up water
Cost effective for larger households with more hot water demand and space

Combi Boiler

Conventional Boiler

Combi Boiler

Runs water from the mains
Immediate hot water and heating
Cost effective for smaller households

Conventional Boiler

Requires hot water cylinder and cold water tank
Requires more room and longer to heat up water
Cost effective for larger households with more hot water demand and space

Tips for Lowering Combi Boiler Running Costs

Making sure your combi-boiler is in tip-top shape all year round is important to keeping combi-boiler running costs down. There are best practices that you can follow at home to look after your boilers and look after the pennies in your pocket when it comes to the end of the month:

Service it annually

One way to keep on top of your boiler to make sure it’s running efficiently is by contacting a local, professional boiler engineer to service your boiler. A certified engineer will be able to assess and diagnose issues with the boiler and provide appropriate fixes. This ensures your boiler is running efficiently all year round and saves you money on your energy bills.

Use smart controls

Thermostats give you enhanced control over your boiler usage for enhanced running efficiency. By not only adjusting the temperature of your boiler but by setting heating schedules to turn your central heating off and on hands-free, smart combi-boiler controls stop you from wasting energy when you’re not home and provide extra peace of mind.

Insulate your home

Improved insulation within the home reduces heat loss and keeps your home warmer for longer. Improving the insulation in your home through added wall or roof insulation, you can reduce the regularity of using your central heating and reduce the amount you spend on your combi-boiler running costs.

Bleed radiators regularly

Trapped air within the pipework of your central heating system can cause your radiators to take longer to heat up when you turn your combi-boiler on. This means that in can take longer to heat your home, leaving the boiler on for longer and costing your more money on energy.

So… Is a Combi Boiler Cheaper to Run?

For most households, yes, a combi boiler is cheaper to run than traditional systems, especially if you have low to moderate hot water demands. Its on-demand hot water, high efficiency, and lack of heat loss from storage make it a cost-effective solution. However, larger homes or properties with high hot water usage may find system boilers or conventional systems more practical despite their slightly higher running costs.

When choosing a boiler, it’s important to consider your home’s size, water usage patterns, and future energy costs. Consulting a heating expert can help you determine the best and most economical option for your specific needs.