Choosing the Best Combination Boiler for Your Needs and Useful Tips

Hot water and heating are very essential in every home. Temperatures rise and fall with the seasons and can get to unbearable levels. Every home needs a regular supply of heat and hot water, otherwise, everything will just freeze over. Maybe not literally frozen but low temperatures can get the better of them. Boilers and heaters come in handy to make things better.

Those interested in savings in terms of space and fuel cost should look at the possibilities of a combi boiler or combination boiler. It works as a central heating boiler as well as a high-efficiency water heater. These two capabilities make it a great choice for any homeowner looking to kill two birds with one stone. It comes with a few other benefits too.

Benefits of Using a Combination Boiler

  • There is no need for a hot water storage tank because the boiler works by taking cold water directly from the mains supply. It then heats the water only when required, like when you open a tap or shower. The water may come out hot but whatever remains behind is still cold. That saves you the hassle of space for a boiler tank.
  • With regard to the way it heats water, it reduces fuel wastage. The system doesn’t heat water you won’t use and this means that it consumes less fuel.
  • The whole unit requires a short time to install. Since there is no storage water tank involved, the amount of pipes required also reduces. That saves you money and time.

The odds definitely look good at face value. These features have actually made the combination boiler the most commonly used type of boiler in the UK. You will find more than half of new home owners are taking this option up and it works well. How then would one choose the right boiler for their home? Here are a few pointers to lead you in the right direction.

Combination Boiler Buying Guide

  1. Type of fuel

Many homes in the UK already have gas heating installed in them as well as gas boilers. This works well with a combination boiler. Other fuel options include liquid petroleum gas, oil and even wood. You will need to figure out the cost of fuel over a certain period of time. This will help you determine the amount you are actually spending on heating and hot water.

  1. Efficiency

Efficiency is all about making the most with the available resources. A boiler may indeed use fuel efficiently and give you more heating and hot water using the same amount of fuel but there’s another component. The Energy Saving Trust says that your boiler accounts for about 60 percent of carbon dioxide emissions in your home if you use gas central heating. The right efficiency rating will allow you to reduce your carbon footprint as well as reduce heating costs. You can help save the world while still spending less money.    

  1. Initial cost

Boilers generally require a large investment at the beginning because buying the boiler and having it installed must be done at the start. Thankfully this only applies at the start unless you will need to replace it many years later. Many will look at the cost of everything and decide to go for the cheaper option. Remember that cheap can be expensive in the long run.

Instead, look for value for money. What features does the boiler have? How long is its warranty? What is its efficiency rating? Will you need any additional items for it to work properly? What kind of service should you expect overall? You need to know in advance if what you are paying for is worth the money that you put into it.     

  1. Heating controls

Not every room needs heating, well at least not all the time. Heating controls on a combination boiler allow you to manage the temperature and also where the heating affects. It will ensure that heating remains active in specific rooms and at specific times only.

  1. Hot water consumption

Water consumption is largely dependent on the number of people living in the home. A smaller household would benefit more from a combination boiler than one with a larger population.

Many get tempted to save costs by installing boilers themselves but this may not be a good idea. Gas heating is a sensitive area and, if installed in a wrong manner, could cause major accidents. Always look for a heating engineer with proper credentials. Check to see if they are listed on the Gas Safe Register or ask them for their Gas Safe Register ID. Shop around for different boiler installation quotes and ensure that they include all costs. Look for call-out fees and do actual calculations even if they have indicated a discount. You can never be too cautious with money and pricing because it will affect your home budget.

A combination boiler is the perfect addition to any regular household due to the savings it offers. Your home need not suffer extra cold due to its physical size or the number of people living in it.

What Size of Boiler Will You Need?

Every house has different heating needs and this is guided by the physical size of the house. Apartments and four-bedroom houses have completely diverse heating needs even when using a combination boiler. Heating engineers know their trade and that’s no secret. It is, however, important that you have an idea about what you need. That way, you will be able to ask the right questions if need be and assure of a proper combination boiler.

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Below is a simple guideline on what different types of homes need. The size of rooms may differ in every home but this will give you a rough idea.

  • Apartments, flats and small houses with about 10 average size radiators and a single bathroom will need a 24 to 27kW combination boiler.
  • A 3-4 bedroom house that has about 15 average size radiators, an ensuite and one bathroom would need 28 to 34kW from a combination boiler.
  • Large houses with up to 20 average size radiators and two bathrooms will benefit from a 35 to 42kW combination boiler.

Important tips:

Where there is a higher demand for hot water a combination boiler with a higher kW will work well to ensure a better flow rate.

A combination boiler will not work well with two showers (or water sources) running at the same time in the same house. You will need to add a tank to make this work well.

Common Problems You May Encounter With a Combination Boiler

Owing to its design and operation mechanism, a combination boiler is bound to have a few hiccups once in a while that are common and not too serious. These are problems that you can handle on your own without having to call a plumber. It would be best if you knew what to expect so that when they do occur you already know what to do apart from getting into a panic.

Pressure Related Problems

  • Pressure is the most common problem, accounting for a good chunk of boiler problems. This is because most combi boilers have a sealed heating circuit. This mechanism requires about 1.5bar pressure for it to start up and function. In the event that the pressure is low the boiler senses this and ‘knows’ that it will not be able to move water around properly. It then locks itself instead of starting.

To fix this, go through the manual. The manual should have diagnostics codes and instructions on how to deal with the issue. Remember to leave the cold feed and filler loop off because that could cause another issue.

  • The opposite is also a possibility and problem; too much pressure. This happens when there is too much water after a pressure drop. It is more common if the system hasn’t been in operation for a while.

Non-Pressure Related Problems

  • As mentioned above the combination boiler can go on lock out mode. This can be caused by different reasons but sometimes all it needs is some time to get it together. It follows a specific sequence when it starts up and if it skips one step the rest can’t happen. All you need to do is switch it off, give it a few minutes and fire it up again.
  • Air in the system will also cause problems.
  • You might need a plumber to remedy this one. If one component is working and the other isn’t, say for example the heating is fine but there isn’t any hot water, the problem might be the diverter valve inside the combination boiler. It is located inside the boiler casing and that’s why it would be best to have a plumber fix it.

Installation Costs for a Combination Boiler

Installing a combination boiler may be simple and will take less time but the cost varies. How much you spend on it will depend on the size you choose, the brand and whether you already have another boiler. Different brands have different costs with some higher than others of course.


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The larger the combination boiler the higher the price will be. About already having a boiler, this means the older boiler is already occupying some space but needs replacing. The technician handling your case will need to move the old boiler to make space for the new combination boiler you want to install. That will increase the labour costs but by what amount will be dependent on the engineer.

Where you live will also affect the cost. High-end areas will charge more and lower-end areas not as much. The company you get your engineer from will also influence how much you spend. They may be biased towards a specific model maybe because they get commissions from sales. If the company is among the established energy firms you may pay more for labour than if you chose a smaller or independent engineer. Whoever you choose, make sure they are Gas Safe Registered and be sure to ask for proof. That said expect to spend about £2300 in total.

Energy Saving Tips

The cost of living is on the rise and doesn’t seem to be letting up any time soon. This has also impacted the cost of other amenities and top among these is energy. Anyone would jump at the chance to cut their energy bill by whatever percentage because heating, hot water and energy in all its forms is here to stay. You’ve probably heard of many different tips to save you cash on your heating bill but some are just a gimmick to get you to buy a new product. What then will actually make a change?

The solution to this could be as simple as a thermostat. A thermostat controls the temperature and in turn the energy consumed. Controlling the temperature, therefore, keeps your energy bill in check. A thermostat could be a fancy gadget that is internet-controlled and requires a whole lesson to master what with technological advancements.

However, a simple and traditional thermostat that looks like a dial will work just fine. All you need to do is turn it up a few degrees and your house will be comfortable enough. It is quite okay if you choose to place seals on doors and windows but temperature control is a more efficient method to keep energy bills in check.

Whether you live in an apartment or a small detached house, there is no reason for you to suffer in the cold. A combination boiler will get your home warm and comfortable as well as give you a good supply of instant hot water whenever you need it.

Seek Advice

Talk to credible suppliers or a technician so as to get their help and opinion on the right one for your home. Your boiler problems will end as well as soaring energy costs. It is safe, cost effective, easy to install, space saving (it can actually fit in a kitchen cabinet) and provides instant service. It will allow you to take things to the next level.