Can you still buy non-condensing boilers?
Non-condensing boilers used to be a staple feature in many homes across the UK. However, thanks to advances in technology and changes to the law, these appliances have now been superseded by condensing designs. Condensing boilers are much more energy efficient than non-condensing models, meaning they can help households to significantly lower their energy bills and cut their carbon footprints.
Keep reading to find out more about the differences between these two types of boiler, and whether it’s still possible to buy non-condensing designs.
What is the difference between condensing and non-condensing boilers?
There are a few differences between condensing and non-condensing boilers, but the main one is that a non-condensing boiler has only one heat exchanger, whereas condensing boilers generally have two.
Non-condensing boilers generally waste some heat when they expel the hot flue gases, but condensing boilers have a second (or a larger) heat exchanger that reuses this heat to make them even more efficient. Once the heat has been removed from the flue gases, the water vapour condenses, hence the appliance’s name.
During this heat exchange process, the temperature of the flue gases can drop quite quickly, from approximately 130℃ to just 50℃. This makes condensing boilers much more efficient. The second (or bigger) heat exchanger can increase the heat transfer time, bringing your cold water up to temperature faster and more efficiently. In fact, condensing boilers are more than 90% efficient, and Viessmann boilers are at least 98% efficient. In contrast, non-condensing models may only have an efficiency rating of 70 to 80%, while in old models (over 10 years) this figure could be even lower at 50 to 60%
The extra efficiency of condensing boilers means they can offer major cost savings and they are also more environmentally friendly, helping you to lower the carbon emissions of your household. And these aren’t the only benefits. Condensing models also tend to be safer. Whereas non-condensing designs, often known as open vent boilers, typically take in air from inside the room, condensing boilers are completely sealed for heat insulation and they take their air from the outside. This means there is a lower risk of anything being sucked into condensing boilers.
When did condensing boilers become law?
Dating from 1st April 2005, all new gas boilers fitted in the UK are required to be condensing models. The same rule came into effect for oil boilers on April 1st 2007. The regulations state that all new boilers installed in domestic properties must be high-efficiency condensing designs.
This change in legislation was driven by the then Office of the Deputy Prime Minister and it was designed to make homes more energy efficient by dramatically reducing the emission of greenhouse gases.
In April 2018, there were further updates to the rules regarding new boilers. Under the Boiler Plus regulations, all new boilers in England must have an Energy-Related Products (ErP) rating of 92% or higher. These rules also require all new oil and gas boilers to have a thermostat and programme timer. In addition, all new combi boilers must include one extra energy saving measure. This could be any of the following:
Flue gas heat recovery system
This system is designed to reuse heat generated by your boiler. In many cases, this technology is already built into new boilers, so doesn’t come with any additional cost.
Load compensating thermostat
This type of thermostat adjusts the temperature of your radiators in accordance with how warm your home is. When your home is cold, it will make your radiators hotter, and when your home is approaching the desired temperature, it will make them cooler.
Weather compensating thermostat
This technology is similar to a load compensating thermostat, but it adjusts the temperature of your radiators based on the outside temperature.
Smart thermostat
These thermostats enable you to control your heating system via your smartphone or tablet, even when you’re away from your home. They offer many of the same functions as a programmable thermostat.
If you’re not sure which additional energy saving feature is best for your home, you can ask your heating engineer for advice.
Do all new boilers have to be condensing?
Because of the building regulations now in place, the vast majority of new gas and oil boilers have to be condensing models. However, there are occasional exceptions to this rule. In rare cases, a condensing boiler may not be a viable option in a particular property. If an assessment carried out by a Gas Safe registered installer suggests this is the case in your home, you may be permitted to get an alternative system.
How do I know which new condensing boiler is right for me?
There are many different condensing boilers available. For example, you can choose between different types of boiler, such as combi or system designs, and there are a variety of sizes available too. You can also get models that are compatible with solar technology, helping you to reduce your bills and your carbon footprint even further.
Deciding which solution is right for your home can be difficult. You’ll need to take a range of factors into account, including the layout and size of your home and your heating and hot water needs. Fortunately, there is help available. You can research your options online. For example, you may find this article useful to help you decide what size of boiler you need for your home. For extra information and advice, you can speak to a heating engineer. They will be able to advise you on your options and help you to make an informed decision.
