Speedy Service -   60 mins Response time
Book online

Table Of Contents

Installing a gas heater in your home is an excellent investment because of the many benefits you enjoy. Gas heaters offer the best solution when it comes to heating large spaces fast and cost-effectively. They use gas to heat water instead of electricity. This means that you save a lot of money on energy bills when you invest in a gas heater for your household.

As you buy a gas heater, there are several factors to consider in the process. Some of the factors you should consider include; the type of gas heater, size, installation requirements, costs, warranty, etc. One of the significant factors to put in mind is the type of gas heater to buy. Gas heaters are categorised into two: flued and unflued gas heaters.

This article will focus on helping you understand more about flued and unflued gas heaters.

1. Unflued Gas Heaters

Unflued gas heaters do not have flue and discharge water vapour and combustion gases into your home directly. Most of them feature a bayonet fitting and hose to allow you to move it from one room to the other. They are usually plugged into bayonet sockets. Unflued gas heaters have higher energy ratings but vent some of the gases inside your home.

These gas heaters burn gas to emit heat and do not have a chimney and heater to move the combustion products outside your house. Some are portable and plugged into a gas outlet through a floor or wall socket with a hose. Others may be fixed on your wall or LPG cabinet heaters. The amount of gas released is specified by government safety regulations.

2. Flued Gas Heaters

Flued gas heaters usually feature a flue that conveys all water vapour and combustion gases out of your home. The fact that no combustion gases are released into your home means that you enjoy clean air. Flued gas heaters usually burn gas to produce heat and use the flue that carries the combustion gases away. You can opt to get an open flued gas heater. Flued gas heaters are both LPG gas and natural gas heaters.

Features of Unflued Gas Heaters

Here are some of the significant features you get when you buy an unflued gas heater.

  • Portable/Not Fixed

As mentioned above, unflued gas heaters do not have flue and release the gases and water vapour into your house. However, it is worth noting that the gas heaters are more cost-effective and energy-efficient. They are also easy and cheaper to install compared to flued gas heaters. They come with a three metres hose to help plug into a bayonet socket.

Unflued gas heaters are portable. Therefore, if you get one you can move it to any part of your home according to your specific heating needs. This is why they are also referred to as portable gas heaters. To move an unflued gas heater, you need to disconnect the gas heater bayonet connection.

  • High Energy Ratings and Cost-Effective

Unflued gas heaters have higher energy efficiency levels than flued ones. This is why they have high energy ratings because no heat is lost through the flue. In most cases, the star ratings of these gas heaters range from 5.8 to 5.9 stars. This shows that they are about 90 per cent efficient when converting the gas to usable heat.

With unflued gas heaters, you may end up saving about 32 per cent of your home heating costs. They are also more cost-effective compared to flued gas heaters. The cost-effectiveness comes because they operate without a flue kit. Besides, they are also easy and fast to install because of the gas bayonet connection.

  • Indoor Emissions

The term flued is used because the combustion gases produced when the gases burns are directed away from your home through a flued gas heater pipe through the ceiling or wall. There are more indoor emissions with unflued gas heaters since all the combustions gases are directed into your home. Therefore, you should take care when using an unflued gas heater in your home.

If you have people who are highly sensitive to combustion gases at home, an unflued gas heater may not be the best option for you to use. However, if you have this type of gas heater at home, you should ensure that you adhere to all the safety instructions provided by the manufacturer. Moreover, ensure that there is enough ventilation in your house. The optimal levels of combustion gases released by unflued gas heaters are always indicated by government safety regulations.

Features of Flued Gas Heaters

  • No Indoor Gas Emissions

A flued gas heater directs all the combustion gases away from your home through a chimney or flue pipe. This means that no gas or water vapour is emitted inside your home. Flued gas heaters are available as LPG gas or natural gas. They are also available in balanced flue models or direct vents that help draw the combustion air from outside your home, meaning less draft.

The level of air drawn is balanced with combustion gases moving out of the flue. Therefore, when you use a flued gas heater, you have peace of mind knowing that your safety and that of your family is guaranteed.

  • Less Energy Efficiency and Costly

Flued gas heaters are less energy-efficient than unflued ones. They have lower energy ratings because some heat is usually lost through the flue. In terms of costs, you pay more because these gas heaters have extra hardware, and more installation work is required.

  • Fixed/Not Portable

Flued gas heaters are not portable. They are fixed in a specific location in your house during the installation process. This means that you cannot move your gas heater from one place to another within your home. The flue kit is fixed through the ceiling or wall, which requires a highly qualified plumber to perform a job.

Should you Buy a Flued or Unflued Gas Heater?

By looking at the above features of both the flued and unflued gas heaters, you may be able to decide the best option to invest in your home. However, to help you make a more informed decision, here are some of the pros and cons of both gas heaters.

Pros of Unflued Gas Heaters

  • Easy to move: You can move an unflued gas heater wherever you want and to whichever room in your house. You can also point the heater in various directions or carry it with you when relocating.
  • Highly efficient: Almost 90 per cent of a flued gas heater’s energy content is usually changed into heat. You can always check the efficiency label to confirm the energy ratings.
  • Give instant heat: Unflued gas heaters provide a lot of energy. They have a capacity of around 25MJ/h. This heat is more compared to what you get from electric heaters.
  • Cost-effective: Unflued gas heaters are cheaper compared to portable electric options.
  • Contain several safety features: It has a wide range of safety features that switch the device off if something goes wrong. This makes the gas heater a safe option to use in your home.

Cons of Unflued Gas Heaters

  • Since they have no flue, all the combustion gases are emitted back into your home.
  • Carbon monoxide is emitted along with nitrous oxides although in small amounts.
  • The water vapour produced can condense on your ceilings and walls. This can cause mould; thus, you should ensure your home is well ventilated.
  • The other indoor emissions may have adverse effects on your health.

Pros of Flued Gas Heaters

  • No emissions: Flued gas heaters are put in a particular area of your home. They feature a pipe vent, also referred to as a flue. The flue helps funnel all the combustion gases away from your house.
  • High-level safety: Flued gases are safer to operate compared to unflued gas heaters. With the flue, it means that only a small amount of combustion gases such as nitrogen dioxide or carbon monoxide remain in your room.
  • Available in large sizes: They are available in a wide range of sizes. It means that even if you have a large room, you can still get a flued gas heater for your home.
  • No mildew and mould: With a flued gas heater, minimal water remains on the walls or ceilings in your house. This reduces the chance of mildew or mould growth.

Cons of Flued Gas Heaters

  • They are not as energy efficient as unflued gas heaters. There is heat that is lost through the flue.
  • They need to be fixed by professional and licensed gas fitters.

How Do you Choose the Best Flued or Unflued Gas Heaters?

Now that you have learned the features, advantages, and disadvantages of flued and unflued gas heaters, you can make an informed selection. However, you still need to consider several factors so that you can choose a gas heater that serves your needs effectively. Here are some of the factors to consider:

  • Your Location and Size of your Rooms

You should consider all the micro-environmental factors to know the type of gas heater to buy. For instance, take note of the level of coldness or the amount of sunshine you get at particular times of the day.

Moreover, you should consider the area the gas will cover. Take note of the number of rooms, size of the rooms, insulation, windows and their measurements, and where you want to place your gas water heater. Remember that unflued gas heaters are not the best option for small rooms like your bathroom and bedroom.

  • Heater Size, Gas Capacity, and Consumption

Considering the size of your space, take time to measure all your rooms to determine the correct gas size to install. The point here is to make sure you buy a gas heater that offers you the proper energy levels you require at home without overspending.

  • Cost of the Gas Heater

You should set a budget before going out to buy your desired gas heater. The main thing is to ensure that you get a heater with all the required features. Take time to shop from different manufacturers to find one selling at the most affordable price. Moreover, you should only buy your gas heater from a reputable brand.

  • Features to Check

Ensure that the gas heater you buy has all the features that make it more functional, safe, and efficient. Some of the features to check include; remote controls, thermostats, programmable timers, and child locks.

Get Some Expert Advice for your Heater

As you can see from the article, flued and unflued gas heaters have various features that make them superb investments for your home. You just need to consider your heating needs to know the best gas heater to buy. You should also ensure that your chosen gas heater is serviced regularly and repaired promptly by a professional plumber to ensure that it works optimally at all times.


Our Customers

Christopher Chow

I called Hero Plumbing to unblock a shower drain and was unable to get a quote over the phone, but Sam the owner was here same day. After his first try, he made quick work of the blockage. I opted to also get the acid cleaner stuff poured down. Sam had run out, but made a trip to go pick some up to finish the job. If you opt for this treatment make sure you can easily air the bathroom as it’s extremely strong and produces a lot of fumes. Great Service and Honest Pricing.

Sarah Lincon

Hero Plumbing has been excellent since there first phone call.
I spoke to a gentlemen names Sam which he organised a technician to come and replace our hot water heater.
The technician was excellent called me 30mins before arrival explained the whole job to me and gave me an upfront price.
Excellent work Hero team.
We are a Hero member now and always look forward to working with them.

Jared Evans

We've used Hero Plumbing previously. Both times reliable and flexible with changing times (helpful during covid ISO periods!)
Hayden was on time and explained the issue clearly, fixed it,then also did some extra checks on water pressure and taps to ensure there were no underlying issues.
Would recommend their services.

Denzi K

Hero Plumbing has been our go to plumber for years.

They replaced our hot water system with excellent workmanship, professionalism and in a timely manner - as always!

Hayden Davidson

Brilliant service from the first phone call to Hero Plumbing as Sam the manager booked us in very efficiently. I received a confirmation  email, a phone call on approach and all went smoothly & work conducted was beautiful . The team did a great job even dig up on our sewer and cut concrete & repaired the issue and our sewer is running like a dream.
Thanks for your great efforts guys!


Victoria Barmina

I knew Sam when he was working alone. And from the first time I was pleasantly surprised by his work. A little later I found out that he has his own business. I am very happy about that. And I am very glad for myself that I have such a company that I can always rely on.

Thank you for your work. People need you very much.

Copyright 2024 Hero Plumbing | All Rights Reserved | Privacy Policies | Terms & Conditions | License No #351669C