Let’s dig into how to turn on a water heater, whether gas or electric, and when it might be time to call in a pro.
Time 20 to 30 minutes
ComplexityBeginner
CostFree
Introduction
Using these simple steps, you will be able to figure out how to turn on a water heater and adjust its temperature.
I recently moved into a newer home and one of the first things we needed to do was turn on the water heater. The good news was that most newer homes with a gas water heater use an electric ignition that sparks the pilot light so there wasn’t a need to light it manually. But that’s just newer gas water heaters, of course there are also electric and even tankless water heaters you might encounter as a renter or homeowner.
The type of water heater you have will determine which steps you take to turn it on or reset it. Make sure to review your water heater’s manual or its instructions, which are most likely located on the water heater itself.
Whether you are turning on a water heater or are trying to reset it because of hot water issues, make sure the water tank is full.
Before getting started, check that the tank is full. If it’s not, the tank could get damaged when the heating system starts up. To do this, simply turn on a hot water faucet, and if it sputters air, the tank isn’t completely full. Following a recent water heater installation, or one that has just been flushed, check that the water supply valve is open.
If you are having issues with hot water and residual air is coming out of the faucet, this might mean there is a leak, or something isn’t working correctly. If this is the case, call a service technician to come out and evaluate your water tank.
If the faucet runs smoothly, go through the following steps to turn on or reset the water heater.
Watch How to Turn on a Water Heater and Adjust Its Temperature
Project step-by-step (9)
Step 1
How to Turn On or Reset a Gas Water Heater With an Electric Ignition
Review the safety information
Be sure to review the safety information that is located on your water heater. Those instructions may differ from what is listed here. This kind of water heater has an ignition device that automatically lights the pilot light.
CAUTION: Never attempt to light the pilot light by hand on a water heater with an electric ignition.
Step 2
Shut off the power
Turn off all electric power to the appliance by switching the circuit breaker to off.
Step 3
Lower the thermostat
Set the thermostat to the lowest setting but leave the ignition switch set to on.
Step 4
Shut off the gas
Switch the gas valve off. Wait about five minutes for gas to clear. Then return to the water heater and smell for gas. Make sure to smell near the ground. If you continue to smell gas do not continue and call your gas supplier. If you cannot reach your gas supplier, call the fire department.
Once you’re done with the smell test, you can turn the gas valve back on.
Step 5
Set the water heater thermostat
Set the thermostat to your desired setting. 120 degrees Fahrenheit is common. For some thermostats, degrees are listed while others say LOW, HOT, A, B, C and VERY HOT. If this is the case, review the manual to see the water heater temperatures those settings indicate. In most cases, A means 120 degrees, B means 130 degrees, and C means 140 degrees.
Step 6
Turn on water heater
Turn on all electric power to the appliance by switching the circuit breaker to ON. If it is still not starting, turn off all electrical power to the appliance, set the thermostat to the lowest setting, turn the gas off, and call a service technician.
Step 7
Turning on an electric water heater
Electric water heaters do not have a pilot light, so they do not need to be ignited. Simply turn on the circuit breaker and wait for the water to heat up. It can happen instantly or take up to 120 minutes depending on the size of your tank (40 gallons = 60-70 minutes, 80 gallons = 120 minutes or more).
If the hot water has stopped, you can reset the water heater by turning the circuit breaker off and then turning it back on. Again, wait 60-120 minutes for the water to heat up.
If that doesn’t work, turn off the circuit breaker, and then go to the water heater itself. There are two panels on the water heater. Take the top panel off with a Phillips screwdriver and remove the insulation. Press the reset button then put the panel back on and turn on the circuit breaker. Wait 60-120 minutes for the water to heat up.
If water hasn’t heated up after 120 minutes, there might be an issue with the water heater and it’s time to call a service technician to repair the water heater.
Step 8
When to call a pro
For further assistance with resetting or turning on your water heater, or for help with any of the following problems, please contact a professional plumber or heating specialist:
- You find pooling water by the water heater. This may indicate a leak.
- The water heater makes odd noises like creaking or a high-pitched squeal.
- The water color changes from clear to dirty.
- The water suddenly smells odd.
Step 9
FAQs
How long does it take to fill a water heater?
30-40 minutes for gas to fill a 40-gallon tank.
Why is my hot water not getting hot?
There are a number of reasons why your water heater may not be working. It also depends on the type of water heater you have. Electric water heaters may have a tripped breaker or a blown fuse, which can turn off the water heater. Sediment build-up from hard water can cause issues with the sensors, pilot lights could be defective, or there could be a leak. If the water heater doesn’t reset, it could be because of a larger issue and a service technician needs to be called.
What is a tankless water heater?
Tankless water heaters provide continuous hot water without a tank of stored water. When a hot water faucet is turned-on cold-water flows through a heat exchange unit which heats it instantly. The only issue is that there is limited output, so most households will have multiple units for simultaneous hot water usage like if you want to take a shower while running the dishwasher.
Water Heater Installation and Maintenance Basics
Learn how to properly install and care for your water heater to avoid costly repairs and maximize efficiency.
