Diagnosing and fixing a thermocouple “no hot water” problem
Inside the burner compartment of your gas water heater, right in front of the pilot light, is a small metal cylinder called a thermocouple. The thermocouple is a safety device that senses when the pilot light is burning. If the pilot goes out, the thermocouple signals the gas valve to remain closed until the pilot light is relit.
A worn out thermocouple is one of the most commongas water heater problems
When thermocouples wear out, the pilot light goes out, the burner won’t light, and you will have no hot water. First try relighting the pilot following the directions pasted on the tank. If the pilot lights but the flame goes out as soon as you release the button after holding it for 60 seconds, then the thermocouple is bad.
It’s possible to replace the thermocouple without removing the burner assembly, and many repair people do this. But removing the burner assembly as we’ve done simplifies the job of replacing the thermocouple and allows you to vacuum out the burner compartment and clean the burner while you’re at it.
Even though this job is simple, don’t attempt it unless you know how to turn off the gas to the water heater and are comfortable with relighting the pilot. You’ll need a few wrenches to remove the burner, possibly a screwdriver to remove the access cover, and a small brush and dishwashing liquid to test for leaks.
Thermocouples for water heaters are readily available at hardware stores and home centers. Remove the old thermocouple and measure it. Then buy the same size replacement. Parts are included to mount the thermocouple in almost any water heater.
Call a repair person if your water heater looks different from the one shown.
FAQs
No Hot Water? Restore It Yourself? ›
How long does it take for hot water to return? Typically, a water heater tank takes 30 to 40 minutes to heat up so if your water heater is still working, you can count on having more hot water come back in that amount of time as long as your system is still working adequately.
How do I get my hot water back? ›- Consider the Water Heater's Size. ...
- Check the Water Heater's Thermostat. ...
- Make Sure the Circuit Breaker Isn't Tripped. ...
- Check the Water Heater's Pilot Light. ...
- Inspect the Water Heater for Leaks. ...
- Flush the Water Heater Tank. ...
- Call in the Professionals.
- Check the thermostat settings. ...
- Check the circuit breaker. ...
- Check the pilot light. ...
- Check for leaks. ...
- Flush the tank. ...
- If all else fails: Upgrade your hot water heater. ...
- Hot water problems, meet expert solutions.
How long does it take for hot water to return? Typically, a water heater tank takes 30 to 40 minutes to heat up so if your water heater is still working, you can count on having more hot water come back in that amount of time as long as your system is still working adequately.
How long does it take for hot water to fully come back? ›Electric Heater
Ideally speaking, an electric water heater takes around 60 to 80 minutes to release hot water with a tank capacity of 40-gallon. If the tank capacity is 80-gallon, the recovery time can be more than two hours.
Standard tank water heaters could have a defective part on the gas control valve. Water heaters might develop a failing pilot light assembly. Electric issues such as a blown fuse, tripped breaker, or electrical connection problem can shut off your water heater—especially electric and tankless units.
What causes hot water to run out? ›Too much hot water demand from multiple sources at the same time. Sediment build up inside of your water heater tank. A broken dip tube. A water heater that is nearing the end of its lifespan.
Why is my hot water not working but cold is? ›If there is only cold water coming from the tap, it is likely your water heater, especially if the cold side is working fine. There are various reasons why water heaters do not heat properly. It may be due to a leak, a build-up of sediment or it could have become unplugged. Try to fix it by flushing the water heater.
Why is my hot water cold? ›Likely, the heating elements inside your water heater are broken or not working properly—or, potentially, your thermostat is incorrectly set. If those aren't the issue, it's possible the power source for your electric water heater has been interrupted—this is commonly caused by a blown fuse or tripped circuit breaker.
Why is hot water not working? ›What does it mean if the water heater is not producing hot water? It is possible that the circuit breaker tripped or a fuse blew, so check those first if you are not getting hot water from your water heater. If that's not the issue, then it could be that the heating element has burned out and needs to be replaced.
Why does it take so long for hot water to come back? ›
Why does it take so long for hot water to come out of your shower and other faucets? There are several reasons; the distance from the water heater, the diameter of the piping, and the flow rate of the water.
How long do you hold the reset button on a hot water heater? ›Step 2: Find the reset button on your water heater. It's usually located near the bottom of the unit, but sometimes it can be on a side or back panel instead. Step 3: Press and hold the reset button for three to five seconds.
Why is my hot water not heating up? ›What does it mean if the water heater is not producing hot water? It is possible that the circuit breaker tripped or a fuse blew, so check those first if you are not getting hot water from your water heater. If that's not the issue, then it could be that the heating element has burned out and needs to be replaced.
Why is my hot water not working but my cold water is? ›If your cold water pressure is fine but your hot isn't, a partially closed valve is a likely cause. Your hot water heater has a shut off valve that can become partially closed.