Why Gas Water Heater Not Working After Power Outage – Troubleshooting Guide

A power outage is a nightmare of its own and the last thing you want after going through such a stressful event is to find out that your gas water heater had stopped working.

A gas-fired unit can stop functioning after a power outage in case the pilot light had gone out. The majority of gas water heaters nowadays require electricity to operate, so you might want to check the circuit breaker, the wiring, and the control board as well.

What Happens to a Gas Water Heater When the Power Goes Out?

What exactly happens to your gas unit will depend on the type of water heater that you have.

An old-style conventional gas heater with a tank usually has a continuous pilot light. If the pilot had been lit before the power outage, the chances are high that the water heater would continue to function.

Even the models that rely on electronic ignition might work if everything is fine with the gas supply.

However, modern gas water heaters rely on electricity not only to spark the pilot but also to monitor the water’s temperature. On-demand units, for example, won’t be able to function in a power outage as the control board won’t have any power.

Tip: if you have a water heater with a tank (gas or electric), turn off the power, water, and gas supply to the unit – the hot water might be able to remain warm for a few days, in some cases.

Read: Gas Water Heater Not Maintaining Temperature

Gas Water Heater Not Working After Power Outage

Your gas unit might fail to operate even after the power is restored simply because the pilot light had gone out. Depending on the type of water heater that you have, you would have to either manually relight the pilot or push the reset button.

Another thing that you can do is check for the gas outage – the supply might have been shut off in your area. To restore gas service, you would have to contact the utility company.

Electric Heater Not Working After Power Outage

Once the power is back to your house, the water heater might fail to work due to two main reasons – the power supply to the unit is still not through or the power outage caused a malfunction in the system.

In the first case, you should check…

  • The circuit breaker – when the power had gone back on, the breaker might have tripped.
  • The wires – some wires might have simply burnt due to overheating.
  • The control board – there might be a loose connection or improper earthing. In any case, attempt to check the control board only if you’re experienced with electronics. 
  • The plug – the components might have loose connections or be damaged.
  • The voltage – your house might start receiving inadequate voltage. If this ever happens the safety features in your electrical system will shut everything down.

If your water heater is receiving power, then one of the following reasons might be to blame:

  • A malfunctioning thermostat
  • Burnt heating elements
  • A tripped reset button

Read: Why Is Gas Water Heater Humming?

Rheem Water Heater Not Working After Power Outage

The majority of Rheem water heaters are equipped with a reset button.

All you would have to do is turn the gas valve to ‘off’, wait for a few seconds, and then turn it back to ‘on’. This should reset the system.

In any other case, look for the red reset button located on the actual unit (right above the thermostat).

Noritz Water Heater After Power Outage

In a Noritz water heater, the water temperature might change after a power outage. You would have to reset the temperature and the flow meter alarm settings.

No Hot Water After Power Outage Apartment

  1. Check the circuit breaker to make sure that it hasn’t tripped.
  2. If the breaker has not tripped, then try resetting the high-temperature limit switch.
  3. If none of the above has helped, then you might have to replace the heating elements.

Read: Why Gas Water Heater Keeps Cycling ON And OFF?

Tankless Water Heater Power Outage

A tankless water heater will not work in case of a power outage as the unit relies on a control panel that is fully powered by electricity.

If you want to be able to use your water heater even in times when the power goes out, then you can go for a battery backup.

To reset a tankless water heater after a power outage, you can try lowering the thermostat down to zero and then taking it back to the desired temperature in a few minutes. 

Water Heater Leaking After Power Outage

It is important to determine where exactly the leak is occurring. If the actual tank is leaking, then you would have to replace the whole unit.

But if you can see water dripping from one of the valves, then tightening the component should solve the problem.

Sometimes a water heater might start to leak from the valves after a power outage because as soon as the power gets restored the pressure inside the unit quickly changes. This difference might make the water leak for a while, but it shouldn’t last for too long.

Read: Why Gas Water Heater Making A Humming Noise

How Do You Reset a Gas Water Heater After a Power Outage?

If your gas-powered unit has a reset button, all you would have to do is push it. The button is usually located just above the thermostat (in the center of the limit switch).

In some cases, you would have to reset the pilot light. This can be done with a match or with an igniter switch (if your unit has one).

How Do You Reset the Heater After a Power Outage?

When it comes to electric water heaters, those usually have a red rest button on the upper thermostat.

Don’t forget to turn off the water heater before pushing the reset button.

How Long Does It Take to Get Hot Water After Reset?

If you have gone through a power outage and you have an on-demand water heater, then you wouldn’t have to wait for the hot water to get restored at all.

With a gas unit, you should be able to get in the shower in about 30-40 minutes, while an electric water heater might take up to 90 minutes.

What Trips the Reset Button on a Hot Water Heater?

A power outage can trip the rest button. In such a case, it’s a quick and easy fix.

However, a tripping reset button can sometimes serve as an indicator of more serious issues:

  • A malfunctioning thermostat
  • A worn-out heating element
  • A broken reset button
  • Poor wiring
  • A breaker that had gone bad
  • A grounding issue

Will a Pilot Light Go Out During a Power Outage?

The pilot light on a gas water heater might be able to stay lit. The unit has a thermocouple that monitors whether or not the pilot is lit and controls the flow of gas.

The pilot’s heat is what makes the thermocouple generate a small electrical current to keep the gas valve open. If the flame was already lit before the power outage happened, it might be able to stay that way.

Read: Why Gas Water Heater Is Not Hot Enough?

Do Gas Water Heater Need to Be Relight After Power Outage?

Once again, it depends. If you already had the pilot light running before the power outage, it might be able to ‘survive’.

However, a malfunction in the thermocouple, gas valve, or any other component might make the light go out, as well as an ordinary draft.

Can a Gas Hot Water Heater Work Without Electricity?

Not all gas water heaters will continue to work in a power outage.

If your unit uses a continuous pilot light, then it might be able to operate without electricity. However, the majority of modern gas water heaters rely on electricity to power the electric ignition control, the control board, the thermostat, and so on.

Electrical Requirements for Gas Water Heater

A typical water heater will be using around 4.000 watts.

If you want your gas unit to be able to work on a 20-amp OCPD, you are going to need a 25- or a 30-amp circuit. Unless the manufacturer requires one, you might not need a dedicated circuit.

A gas-fired unit usually uses about 12 amps with 115 volts, so the average 40-gallon tank model would require a 30-amp breaker.

Does Power Outage Affect Hot Water?

An electric water heater and some gas units will stop heating the water in the event of a power outage. The good news is that the water that has already been heated up will remain hot for quite a while inside the insulated tank (up to a couple of days, in some cases).

Tankless water heaters won’t be able to provide any hot water at all.