Whether you need to replace a faulty boiler or just want to upgrade an old unit, there is an awful lot to consider. Replacing this vital part of your central heating system is not only expensive, but it can also be complicated. And given that few people ever buy more than 3-4 boilers in a lifetime, it’s not something you are likely to have a lot of expertise in.
You need to ensure you buy the right size, the right type, and also think about how much you can afford to invest. In this guide, we’re going to take you through everything you need to know about buying a new boiler, so let’s get stuck into the basics.
Let’s be frank – most people only ever buy a new boiler when they need to replace an old one. So, the first step in the process should always be making sure you need to swap out a faulty boiler, or if, in fact, there is a repair available. Your best bet is to call up a Gas Safe engineer to give you a professional opinion, and then it’s just a case of weighing up the cost of repair against the cost of a new unit. If your boiler is old, however, it might be worthwhile swapping out anyway. Finally, you should also consider replacing a boiler with a rating of ‘G’ for energy efficiency., These types of units are the worst for keeping your energy costs down, and in the long-term, the new boiler should pay for itself after a relatively short period.
There are a variety of boilers on the market at the moment: a regular or conventional boiler, a system boiler, or a combi. Each of them works in a slightly different way, so let’s take some time to explore your options.
If you have an open-vented heating system, most specialists will recommend you go for a conventional boiler. Units like these store water in a cylinder, and usually give you a reasonable flow rate, with an instant supply of hot water. If you intend to use a power shower, these types of boilers are often your best choice, as they need a separate electric pump to help push the water around the system.
However, it’s not all sunshine and rainbows. Regular boilers are expensive to install, and you might need to invest in extra shower boosters if you have a low-lying cistern – which can result in low pressure. Also, unless you are careful with the amount of hot water you use, it can run out.
Just like regular boilers, system units store hot water in a cylinder and are fitted to sealed heating systems. They are a good option for houses with a lot of space and are much cheaper to install than a conventional boiler. They also tend to have a high flow rate, and you can rely on having hot water at all times.
That said, the system boiler is not without issues. Again, like the conventional units, you can run out of water if you aren’t paying attention. And some boiler experts believe that they cause a lot more problems over the years than standard units.
Combi boilers are a popular choice these days and work in a sealed system – much like system boilers. However, there is a critical difference in that they heat water direct from the mains. If your home is short on space, a combi boiler is your best option, as there is no need for a tank or cylinder. They are quick and – relatively – easy to install and supply a reasonable flow rate.
There are issues with combi boilers, though. It’s usual for them to struggle to handle more than one heating task at a time, and you can often experience flow problems when someone is in the shower, and someone else is running water from the kitchen tap. You will also struggle to get the best possible performance from a combi if your external pipe measures less than 22cm.
There are no hard and fast rules about the size of boiler you need, of course. However, there are a few guidelines to consider if you want to ensure a high-quality performance and maximum comfort. For example, a boiler of 24-25 kW is going to be a good choice for small flats and homes, with a maximum of 10 radiators. If you have a larger home – say, with 3-4 bedrooms – you are better off going for 28-30 kW boilers.
However, if your home contains between 15-20 radiators, your best option is to size up to a 33-35 kW option, and anything more substantial than that should be OK with a boiler powered by more than 40 kW.
You can spend a lot of money on a boiler and go for the most energy-efficient unit you can possibly find. But ultimately, it won’t make a lot of difference if you don’t know how to use it properly or find the right settings that deliver water and radiator temperatures hot enough but are also inexpensive to run.
The most important thing to remember is to learn how to use your central heating controls correctly. For a relatively small investment, you can get a highly advanced room thermostat and timing unit, which will help you keep close control over everything from min and max temperatures, automatic on and off, and also that you only heat rooms where it is absolutely necessary.
A final point – no matter how good our boiler is, you should always arrange to get it serviced on a regular basis. Boiler servicing will help you spot any small problems that could end up developing into something more problematic. If you don’t keep close tabs on the inner workings of your unit, there’s every chance it will end up giving you trouble over time.