If your water heater gets switched off, it means you won’t have any hot water for taking a hot shower, washing the dishes or anything else, which, understandably is not an ideal situation.
However, turning a heater back on once it’s gone out is usually a relatively simple job that anyone can do – so in this post, we talk about how to turn on a water heater as well as giving you some information about why they turn themselves off and what you can do about it.
Different types of water heater
Before we talk about how to turn on water heaters, we need to say a few words about the different types that exist.
This is because the type you have will dictate how to get it started again if it goes off – as well as what you need to do to troubleshoot it if you have problems.
In the past, the most common type of water heater consisted of a tank of water that was heated by gas – and these types of heaters are still popular today.
Unless you have recently replaced your water heater or have recently bought a new house, there’s a good chance this is the type you will have.
Another popular kind of water heater also features a tank, but instead of being heated by gas, the water is heated by electricity.
These are a popular choice for smaller tanks, and since they don’t directly burn fossil fuels, they are better for the environment. However, it is usually more expensive to heat water using electricity, so they are less economical if you need a big heater.
Finally, the most modern type of water heater is the on-demand tankless heater. This type heats water as it is needed, so it doesn’t need to be heated and then stored in a tank.
As a result, they don’t waste gas or electricity heating water when it isn’t needed, and since water is heated as it is required, nobody will ever need to take a cold shower because the hot water has all been used up.
So now we know about the main types of water heaters, we can have a look at how to turn each type on.
How to turn on a traditional gas-powered tank water heater
Let’s start with the traditional gas-powered tank heater. Here’s how to turn one on if it’s been switched off – although bear in mind that different models function differently, so you should also check the instructions that are attached to the side of your heater.
Step 1. Close any open faucets
If your water heater was turned off because you were working on it, the first thing to do is to close any faucets that you opened to release the pressure on the system. This won’t be necessary if the pilot went out by itself.
Step 2. Turn on water supply to fill the tank
Again, if you were working on the tank, you probably turned off the cold water and drained it. In this case, you need to turn the cold-water supply back on to refill the tank before lighting the pilot because heating an empty tank may damage the heating elements.
Step 3. Shut off the gas supply
Find the gas shut-off knob and turn it to “off”. The gas valve is usually located at the front of the heater towards the bottom and should be clearly labeled. Once you close the valve, leave it for five minutes to allow any gas to dissipate.
Step 4. Open the pilot light cover or door
If your heater has a door or a cover that protects the pilot light, open it. However, some heaters don’t have one, in which case there will just be a gap giving you access to the pilot light.
Step 5. Locate the burner
Look inside and try to find the burner. You can identify it by the two small gas tubes leading to it.
Step 6. Turn gas knob to “pilot”
Turn the gas knob to the “pilot” position and then hold it down. Putting it in pilot mode will allow gas to flow to the burner, which you can then light.
Alternatively, some burners have a separate button for lighting the pilot – if yours does, it will probably look like a red button. If you find this, press and hold it down instead.
Step 7. Light the pilot
When the gas is reaching the burner, you need to light it. Some heaters have an igniting button that you need to press – it will be either red or black. If your heater doesn’t have one, you simply need to light it manually using a long lighter.
Step 8. Hold knob then release slowly
Once the pilot has been lit, hold the knob for a further minute. After this, release the knob slowly to ensure the pilot stays lit.
Step 9. Turn the gas on
Turn the gas knob back to “on”. You will hear a distinctive whooshing sound as the main burner ignites, which means you’ve successfully lit the heater. Replace the cover or door – and you’re done.
What to do if gas-powered tank water heater keeps going off
Usually, a gas water heater goes off because the pilot light has been blown out, which can happen because of a gust of wind or a change in pressure. In this case, you just need to relight it once and everything should be fine.
However, if your heater keeps switching off, you need to find out why since it may indicate a more serious issue.
Usually, gas heaters turn off due to a problem with the thermocouple, the device that switches the gas off to prevent a leak if the pilot gets blown out.
However, before looking at the thermocouple, check that the pilot flame is receiving enough combustible air to burn. Make sure there is no clutter around it and that the interior of the heater is clean and free of debris, lint and anything else.
If this doesn’t help, the next thing to check is if the thermocouple is bent. It should sit over the top of the pilot flame, but if it gets bent out of place, it will keep switching the gas off when you light the pilot.
If it’s bent, bend it back into position and try lighting the pilot again to see if the problem is fixed.
If this doesn’t help, you can also try cleaning the thermocouple with a microfiber cloth and some steel wool. If it is dirty, it may no longer work correctly, so cleaning it may resolve the problem.
If this doesn’t resolve the issue, the next thing to try is replacing the thermocouple. They can be picked up from hardware stores for around $15, so it isn’t a particularly expensive fix.
If this doesn’t work, it’s probably time to call in a professional to check your plumbing to try to identify the problem.
How to turn on an electric tank water heater
Turning on an electric tank hot water heater is easier than turning on a gas one. Here’s how to do it.
Step 1. Close any open faucets
If you were working on the tank, close any faucets you opened while you were working.
Step 2. Turn on water and refill the tank
If you were working on the hot water tank, you probably emptied it, in which case you need to turn the water supply back on to refill it and avoid damaging it by heating it while it’s empty.
Step 3. Remove lock-out tag
When working on electrical components in a system, it’s good practice to place a safety tag on the breaker panel to tell other people not to switch it back on while you’re working.
This simple action is something that can prevent you from receiving a nasty electric shock and can potentially even save your life.
If you followed this procedure, once you are ready to turn the water heater back on, you can remove the tag from the panel.
Step 4. Turn the circuit breaker back on
Now simply switch the power back on at the wall panel. With most electric water heaters, there’s nothing to tell you that the heater is switched on, so you’ll need to listen for the tell-tale signs that the heater makes as the water begins to warm up.
Step 5. Check after 30 minutes
After 30 minutes, open a hot water faucet and check the water. It should be hot now, or at least it should be noticeably warming up.
Step 6. What to do if it keeps going off
If an electric heater keeps tripping the circuit breaker, it means there’s a problem – although unless you are competent in working with electric appliances, it may be difficult to work out where the problem is coming from.
If you don’t know why the circuit breaker keeps tripping, it may be better to call out a qualified electrician to find the cause.
How to turn on an on-demand water heater
An on-demand heater is probably the easiest of all heaters to switch on since it just requires you to turn it back on at the breaker panel.
Flick the circuit breaker switch back to “on” and check the temperature dial setting is correct – and that’s all you need to do.
What to do if on-demand water heater keeps going off
If your on-demand heater isn’t working, check that it is plugged in and switched on. This might sound obvious, but this is among the most common problems.
However, if the water heater keeps causing the circuit breaker to trip, you should call out a professional electrician to find out where the problem is coming from.
Tips and advice
Here are a few extra tips and pieces of advice that will help you keep your water heater working well and help you find the source of the problem when it stops working.
1. Check for gas smells
Before you relight a gas heater, sniff the air for gas smells before lighting the burner.
The propane and natural gas used in heaters are odorless and colorless, making them impossible to detect in their natural form. However, gas companies add a chemical called mercaptan that gives them that distinctive sulfur smell of rotten eggs.
If you detect this smell, don’t light the burner. Instead, turn off the gas, and open all your windows – because if there is a gas leak, trying to light the burner can cause an explosion.
If you think there is a gas leak, after turning off the gas, you should leave the house and call out professionals to inspect it.
2. Find the reason if keeps going off
Whichever type of heater you have, if it keeps going off, you should try to find out why rather than just keep relighting it.
If it goes off constantly, it means there is something wrong with it, so you need to find out what it is to get it working properly as well as to avoid all danger.
3. Check for dirt and rust on your burner
If your gas burner won’t light, check it for rust and dirt because this is another reason that sometimes they go out or won’t light.
4. Keep face away from pilot when lighting
When lighting a pilot light, keep your face away from the gap. This is because a buildup of gas inside may ignite, creating a large flame – which is something you don’t want happening near your face.
5. Check for bare wires
If you have an electrical heater that is malfunctioning, even if you don’t have advanced electrical skills, something you can do is check for bare wires and any loose connections – since this could be what is causing the circuit breaker to trip.
6. If a heater keeps tripping, it may need servicing
If a heater keeps tripping, it could be a simple case of the heater needing a service. Having heaters serviced regularly will keep them in working order for longer, and having one serviced when it stops working correctly may prolong its working life.
7. Check the manual
If in doubt, don’t forget to consult the user’s manual that came with your heater since it will give you the specific details about how your model works and how to troubleshoot it.
Many people don’t think of checking it, but the user’s manual often contains many of the answers you’re probably looking for.
An easy job anyone can do
When your water heater gets switched off, you don’t need to call out the pros right away since switching it back on is an easy job you can manage yourself.
However, if it keeps switching itself off, it can point to an underlying problem, in which case you need to find out why it’s doing it. That may mean calling out a qualified plumber or electrician might be your best option.