What Is A Combination Boiler?
You may hear the term combi boiler or combination boiler and wonder if they are the same thing, the answer is yes they are!
So if you are asking yourself, whats a combi boiler?
Basically, it is a combined solution of a water heater and central heating boiler as a compact unit.They provide both heating and hot water on demand without storing any hot water in tank.
What a combi boiler system is:
Combi boilers are a great space-saving option if you do not have space for a separate hot water tank or just prefer a one unit system.
How combi boilers work:
Combi boilers are designed to kick out hot water immediately from the mains rather than storing the hot water.
Combi boilers remove the necessity of a hot water tank or a cold water cylinder unlike regular and system boilers.
This is why it has become the most popular boiler system in the UK.
The only downside to a combi boiler is they can struggle supplying water to multiple taps at once. This is the advantage that system and regular boilers have over the combi boilers.
After saying that is the downside, but you have already fallen in love with the sound of the combi boiler, don’t panic because the Viessmann 111 Storage combi boiler works the same as a system boiler but it is still only one unit!
The Viessmann 111 Storage Combination Boiler
This boiler is still to be wall mounted but it has an in-built stainless steel storage tank with the ability to fill a bath within 8 minutes!
This touchscreen boiler can also be connected to any smartphone or tablet by an app so you can control it wherever you are in the world.
This gas combi boiler is known to be rapid, reliable and efficient as well as being able to supply homes with a higher amount of water on demand than the normal combi boiler.
In this article, I’ll break down everything you need to know about a combi boiler.
We will even tell you what the best combi boilers are to buy.
Read on to find out what’s a Combi Boiler
A combi boiler always runs in standby mode.
It never stops in the day; rather it constantly waits for having an instruction to start heating water and supply it instantly.
Even, when you sleep in the house, it is still kept in standby mode. So, whenever you deal for having hot water, it will instantly perform your watery request within a few moments.
How great is that?
A combi boiler does not only provide you with hot water instantly it doesn’t require any water tank or storage cylinder to store water in it.
When you start running your shower or tap once in the combi boiler, it whooshes from the main and goes through the combi to get all fired up.
This is like magic and it happens because of the heat exchanger.
The heat exchanger is powered by oil, gas or electricity.
When hot water starts tumbling out at the powerful shower end or from the hot water tap, you will just find that the water was cold a moment ago. Some boiler types have varying ranges of water boiler pressure.
We often get asked if you can just use your combi boiler for hot water without heating and the answer is, yes!
We also hear combi boilers hot water only works when the heating is on, this is incorrect.
Types of Combi Boiler
Mostly, gas combi boilers are used in the UK and they are most commonly installed by a Gas Safe engineer which can be validated on the Gas Safe Register.
However, combi boilers are also available in LPG, oil or electric and come in a range of different kW output flow rate sizes. If you are wondering if combi boilers are gas or electric, the information below will answer your question.
Gas Combi boilers:
These are the most commonly used boiler in the UK. Gas reduces fuel bills more than any other fuel.
So, if your home is connected with a gas network then it will be the best option for you to use a combi boiler that runs with gas.
Gas combi boilers are the most efficient being A Rated and as said above can save you money on fuel bills.
LPG Combi Boilers:
LPG stands for Liquefied Petroleum Gas.
It is combined gaseous hydrocarbons which are produced from oil extraction (65%) and oil refining (35%) as well as the compound natural gas.
Oil boilers are also executed in the same way.
The boiler should be supplied through fuel from a tank in your garden and needs to be refilled when running low.
Oil Combi Boiler:
If your home doesn’t have a gas connection included, then an oil combi boiler will be the best choice for you.
These types of boilers are usually used on homes and businesses that are off grid and are completely different to a combi boiler or conventional boiler.
You will need to keep an oil tanker outside of your home.
The tanker would need to be topped up with a supplier as it runs out after using day after day. Oil combi boilers can cost more than the gas boilers.
Electric Combi Boilers:
An electric combi boiler is a bit different than other combination boilers.
They do not run through burning fuel. Instead of that, the water passes over a piece of electric equipment as it goes through a hot water cylinder added by an immersion heater.
Electric combi boilers will be the best alternative for the homes where there is no connectivity to the gas mains.
Using an electric boiler might be relatively expensive.
You will however not require a boiler flue for an electric boiler.
An electric combi boiler may not be recommended for larger homes as the electricity consumption will be higher meaning the bills could be costly.
What is a Condensing Boiler?
A condensing boiler prevents waste gases.
Condensing boilers are fitted with 2 heat exchangers internally to make sure less heat escapes without been used.
The difference between a condensing boiler and a non-condensing boiler is – non-condensing boilers don’t include a Flue Gas Heat Recovery System.
When a boiler is running it produces waste flue gases but using an old non-condensing boiler these gas won’t be used and then get wasted unlike the condensing boiler.
Condensing boiler systems mean that the boiler won’t need to work as hard to heat the water. So the boiler uses less energy meaning the fuel bills we lower.
A combi boiler can also be a condensing boiler. A Flue Gas Heat Recovery system would be fitted to the combi boiler to then make your boiler a Condensing Combi Boiler.
It is possible to make any system, regular or combi boiler condensing to save fuel wastage and reduce fuel bills.
The difference between a condensing boiler and a non condensing boiler is the condensing boiler stops any fuel wastage and reduces the fuel bills.
What Is A Heat Exchanger?
A Heat exchanger is the medium to transfer the majority of the heat from the burnt gas to cold water.
Then, it starts circulating the hot water around to the taps as it required.
So, it works like, you turn the hot tap and the combi boiler sends energy to the cold water securing on-demand hot water as needed any time of the day.
Besides the central heating process, the combi boiler will kick in when drop below to the preset settings of the thermostat.
It sends a signal to the boiler’s expansion for hot water to pump around the radiators. That’s why, the heat exchanger is a crucial thing for the combi boilers.
It then converts the energy (heat) from gas over to the water. The water feds out into the central heating system through a flow pipe and voila your home will be warm!
Benefits of A Combi Boiler
- Combi boilers are highly energy-efficient. As of 2019, it was reported that combi boilers installed in the UK have the highest efficiency rating of 92% where only 8% of the fuel is wasted only. It will help you significantly to lower your home’s carbon footprint which will ultimately reduce your heating bill.
- If you look at other traditional boilers, they only provide you an efficiency of 55% where combi boilers provide you fairly a lot more than that. As the efficiency of the combi boiler is 92%, so when you spend £1 on the energy it only wastes 8p which is relatively much lower. As a rough and estimated calculation, if you replace a non-condensing boiler which has less than 70% efficiency with a condensing boiler, then it will save you more than £300 on heating bills per year.
- Unlike other traditional or system boiler, combi boilers come in one compact unit providing all solutions in a package. So, you won’t require to use bulky water tank, cylinder or any other storage that would hold your space.
- As it is an all-in-one unit, it doesn’t require extra elements or pieces to install it. That’s why it is relatively easier to install than any other boilers and more cost effective for the buyer.
- Combi boilers provide hot water on demand anytime only by tapping once or multiple at the same time. They always run on standby mode and waits for your instruction to kick out hot water via your thermostat.
The Installation Cost of a Combi Boiler
The installation cost of a combi boiler varies after considering a few factors like the size, output, maximum flow rate and the name of the brand too.
The more powerful boiler you purchase, the larger home the boiler will be suitable for.
You may also tend to cut costs but it may hamper the suitability of the boiler in your home.
You or your Gas Safe engineer should choose the best boiler which fits your home well and will meet all your requirements regardless of the installation and overall costs.
The cost of installing a combi boiler in a different place is around £1,500 to £3,500.
If you would like to replace your boiler and install a newer one on the existed set up then the cost would reduce to £1300 to £3000.
Much of the cost involved is labour costs and if the boiler has to be relocated or if there are lots of pipe work that needs to be moved.
What Size kW Combi Boiler Do You Need?
You need to know the right size output flow rate of the combi boiler for your home.
If you have higher hot water demand, then a smaller boiler won’t fit your requirements of having enough hot water within a very short time.
On the other hand, if the boiler is too big, it will waste energy and your heating bill will be larger than is needed.
So, after thinking broadly about your needs of hot water and the ability of the combi boiler to supply you that sort of high demand hot water, you should select the right sized combi boiler for your home.
A Gas Safe engineer can help you make this decision or if you go to the Boiler Central website, answer 9 questions, within 20 seconds you will be recommended the best boiler at the best price to suit your home.
Combi Boiler Conclusion
Combi boilers are a very good choice for small homes.
It is not recommended for a larger home where more than 2 bathrooms are located and over 5 people live. Unless your Gas Safe engineer thinks the Viessmann 111 Storage combination boiler will be suitable.
In this case, homeowners are often recommenced to go for a system boiler or regular boiler to store a higher volume of hot water in the dedicated hot water storage. The only issue with a system or regular boiler is they require extra storage space.
So there you have it, if you are still wondering what is a combi boiler or would like to know more, get in touch.