Put simply, yes you can install a water heater outside though there are certain considerations of which you need to be made aware first.
Before you rush to buy a water heater and find a spot for it outside, think about whether you truly need to install it outside.
This may be a good option if you have a relatively small living space, though the installation and the possibility of increased energy costs are worthy drawbacks to consider.
In this guide, we will look at the reasons why you should install a water heater outside, the pros and cons, the considerations, and how to install certain water heaters outside.
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Why You Should Consider Installing A Water Heater Outside
If you have a limited living space, you may consider installing a bulky appliance outside. That may be the case for a water heater and it is possible to install it outside though there are certain caveats.
Such an awkwardly shaped appliance can use up a sizable amount of living space and can become an eyesore.
Whether it is installed in your bathroom or even making a noise in a closet, such appliances can prove difficult to hide and annoying to deal with.
There are more discreet and compact models available but even they are likely to cause noise and cannot be ignored. Installing one outside is out of sight but not necessarily out of mind.
The water heater does not even have to be one of the more modern designs as you could have a traditional tank-style water heater that still works just as well but does not use up your valuable living space.
The Pros Of Installing A Water Heater Outside
The obvious reason for installing a water heater outside is to reserve more of your living space and to keep the appliance out of sight when it could become an eyesore.
There is also the safety aspect of a water heater as the hot water can reach a temperature of around 75°c which can cause serious burns if it leaks.
The Cons Of Installing A Water Heater Outside
With full exposure to challenging weather conditions, it can be a risk to install your water heater outside.
Though the water heater will have built-in protection to combat the worst effects of freezing temperatures, it may not be the unit that is directly threatened but the pipes leading to it.
Should you expect cold temperatures in the winter months, you should take the precaution of insulating every pipe that is attached to the water heater, whether tankless or not.
Pipe insulation can be an inexpensive but effective means of protecting your outside water system. Should the water in the pipes freeze then this ice can expand and crack the pipe which would lead to a leak.
You may already have some surplus after insulating some other outside pipes but if you do not, you can pick some up in a hardware store.
The insulation should look like hollowed-out pipe noodles that surround the pipe to keep out the cold and protect them from freezing.
Though you would be saving on floor space and valuable living space, you may find that your energy costs increase, certainly when installing a tank-style water heater.
If you are comfortable with the arrangement and do not have periods of cold temperatures to deal with then installing your water heater outside should be straightforward.
The Considerations For Installing A Water Heater Outdoors
As long as it is not a heat pump water heater, you should feel comfortable installing your water heater outdoors (see also ‘Everything You Need to Know About Outdoor Water Heaters‘). There are certain considerations to take into account yet it is feasible.
Especially if you live in an area that benefits from a mild and dry climate, though most kinds of precipitation should not be a huge problem.
A simple protective shelter, even a lockable cabinet, should be all you need to ensure that your water heater is safely housed when outside your home.
You could build a proper enclosure yourself if you are adept at such DIY tasks though you could pay someone to build one for you.
One of the most basic considerations should be to ensure that a water tank is elevated off the ground as it is better to be safe than sorry when leaving something outside to face the weather.
Any water that has the possibility of pooling can eventually end up creating rust or corrosion which is why galvanized steel is a popular material though it can be expensive.
Tankless Water Heaters
One of the most popular variations of a water heater is a tankless one which can easily be installed outside. This is largely due to their discreet small size and weatherproof, watertight housing.
They also come with self-warming capabilities that should prevent them from freezing in the cold winter months.
One drawback is focused on the tankless electric water heater as that may suffer some damage when suffering through a prolonged power outage in winter.
With the electricity off, the water that circulates inside can eventually freeze which can inevitably lead to burst pipes in extremely cold temperatures.
This is largely why outdoor water heaters are not a good idea if you live in a region that can expect cold weather unless you have a gas-powered one.
Tankless Electric Water Heater
A tankless electric water heater (see also our guide on transporting a water heater) can be installed on an external wall and you could do this yourself.
However, it is advisable to give a tankless electric water heater some protection and shelter from the weather such as a simple fence or a decorative cover that can hide it.
First, remove the old water heater and test any electrical wires with a multimeter.
Take the time to unscrew any bolts that you can find throughout the unit then mount your new tankless electric water heater to the wall.
A tankless electric water heater is a great option if you have a small living space such as an apartment or condo.
While you may primarily want one to heat your home, other uses can include heating your outdoor shower or pool house which does not require a huge amount of hot water.
Even a tankless electric water heater may only last around eight to ten years before requiring a replacement.
If you have an expanding family or are considering a move then this may be something you think about which could put you off moving your current electric water heater or installing one outside.
Tankless Gas Water Heater
A tankless gas water heater should not require any shelter or protection from the elements so it may be easier to install.
The installation process is quite similar to that of an electric water heater though without the shelter but you would still be advised to insulate the pipes.
With a gas water heater, you will need to connect the gas line as well as the wires to your unit.
Whether an electric or gas tankless water heater, the unit will have built-in venting on the front which is the equivalent of the vent flue attachment on the top of an indoor tankless water heater.
Tank-Style Water Heater
If you do decide to install a tank-style water heater, you should do your best to prevent it from freezing.
Try to find a relatively warm place outside to install your water heater where it is hopefully exposed to some sunlight.
Drain the water heater and then maintain its power source, you may even want to think about a recirculation system to keep the warm water flowing.
The most important aspect of installing the water heater outside is to make sure it is adequately insulated which includes the tank and the pipes, only then should you run a trickle of water to check it.
Installing a tank-style water heater outside does mean providing some sort of shelter, whether it is gas or electric-powered.
You could install yours in an external storage area or the garage though you could devise an outdoor enclosure or weatherproof shelter if the winters are not too harsh where you live.
There is one subtle difference between the tankless and tank-style water heaters and this is that the tank models typically prove less energy efficient as they work harder to heat the water.
Deciding on your shelter can prove tricky as there are various materials and sizes to consider.
For instance, a galvanized steel enclosure should not have the water heater firmly on the ground so you would need a raised platform or a steel raised water heater stand and this is purely to ensure that the water fails to collect at the bottom of the enclosure which could rust and corrode the tank.
Furthermore, if you have a gas-powered water heater then you do not want any water to collect in the burner chamber.
You could create an outside water storage building and, if so, think about using a water heater blanket.
Heat Pump Water Heater
Alas, you cannot install a heat pump water heater outdoors due to the huge variations in the temperature of the surrounding air.
Installing one outside in an unheated space, such as on an external wall or in a garage, would mean that the water heater relies increasingly on the electric mode which would result in substantially higher energy consumption and costs.
A heat pump water heater is also taller than a tank-style water heater and they would require a large environment to operate properly.
While you may be tempted to install one outside, it would be recommended to use a laundry room that can guarantee 100 square feet for sufficient surrounding airflow.
Frequently Asked Questions
How Do I Protect My Water Heater When Outside?
It can prove relatively simple to ensure that your water heater is protected when installed outside.
There are two crucial aspects to consider and those are that it remains to receive constant power and is well-insulated.
Use pipe insulation that looks like hollowed-out pipe noodles that can prove to be an effective and inexpensive option to protect the pipes from freezing and cracking.
For a tankless water heater, you should consider a recirculation system that acts as a small storage reservoir to keep a ready supply of warm water through the pipes.
In What Way Does The Outside Temperature Affect A Water Heater That Is Installed Outside?
Unfortunately, the outside temperature does have an effect on the water heater when it is installed outside, especially when it drops significantly.
When confronted with cold air, the water heater has to push to work harder to warm up the water as more heat will be lost in atmospheric cooling.
Even insulating the pipes will have little effect on the water heater as it will suffer heat loss and you may expect higher energy costs in winter.
Installing any type of water heater could be a tricky DIY job so if you do not need to insist on saving money, you can call a plumbing specialist to do it for you. Once one is successfully installed outside, it should last for years.
However, electric water heaters may only last for around eight to ten years before needing to be replaced and heat pump water heaters should not be installed outdoors so that may be a consideration.
As long as there is enough combustion air for the tankless water heater (see also ‘Wood Burning Water Heaters‘), you can safely install one on an outside wall or even in the garage.