Thermal Cut Off Switch (TCO): The water heater is also equipped with a resettable thermal switch, designed to shut off the gas supply in the event the water heater has been exposed to high combustion chamber temperatures caused by flammable vapors (e.g. spilled gasoline), poor combustion caused by a blocked vent or
What does a water heater thermal switch do?
A thermal switch is installed in newer gas water heaters as a safety device. Blocked vents at the top and bottom of the water heater can cause excessive heat buildup inside the chamber and trip the thermal switch, shutting off the gas supply to the burner assembly.
Where is the thermal switch on a gas water heater?
On a typical residential gas water heater, the TCO is a manually resettable thermal switch located on the front of combustion chamber door. The TCO is integral with the thermocouple or thermopile depending on type of gas control valve.
What is the most common problem with a gas hot water heater?
Some common problems for all types of Hot Water Heaters are, pressure relief valves, leaks, sediment, drain valves, anode rods and dip tubes. A general troubleshooting discussion is provide in the article, ‘Identifying and Repairing Water Heater Problems’. The danger with a gas hot water heater is the gas itself.
How do you reset a thermal switch?
The thermal switch can trip if the water heater is not getting enough air. Press the small reset button in the center of the thermal switch. If it’s tripped, you may be able to hear it click. Even if you do not hear the thermal switch click, try lighting the pilot using the instructions on the water heater’s label.
Does a thermal fuse reset?
A thermal fuse is a cutoff which uses a one-time fusible link. Unlike a thermal switch which may automatically reset itself when the temperature drops, the thermal fuse is more like an electrical fuse: a single-use device that cannot be reset and must be replaced when it fails or is triggered.
The high resistance caused by a loose wire produces a substantial amount of heat that can eventually cause fires. If there is a loose electrical connection within your water heater’s system, your reset button’s thermometer can trip (regardless of the water’s temperature) if it picks up the heat from that loose wire.
How does a thermal fuse work?
A thermal fuse or thermal cutoff is a safety device which open circuits against overheat. It detects the heat caused by the over-current due to short circuit or component breakdown. Thermal fuses do not reset themselves when the temperature drops like a circuit breaker would.
Why does my hot water tank keep shutting off?
If your gas water heater keeps shutting off, the thermocouple could be dirty, bent or damaged. The thermocouple is usually easily visible next to the pilot light.If it is dirty, turn off the gas to allow the thermocouple to cool. You can then clean the thermocouple by gently sanding it with fine sandpaper.
How do you trick a thermocouple?
The thermocouple always thinks the pilot is not lit, even if it is. To get hot water, I have to light the pilot, then hold the match on the thermocouple to trick it into thinking the pilot light is touching it. Once it’s warm enough, I pull the match out and turn the knob from “Pilot” to “On”.
How do you know when a gas water heater is going bad?
7 Tell-tale signs of a Water Heater not working
- You don’t have enough hot water.
- You have varying water temperature issues.
- You have a leaking water heater.
- You notice reduced water flow.
- You’re hearing some concerning sounds.
- You have smelly or discolored water.
- Your water heater is on the older end of the spectrum.
What is the lifespan of a gas water heater?
8 to 12 years
The type of water heater and where you are located: While many say 8 to 12 years is the expected life for a standard gas-powered water heater, this range can change and be very dependent on where you are located. The level of sediment in your tank affects the lifespan of your water heater.
Why is my gas hot water heater not getting hot?
Is your gas water heater not hot enough? If you find yourself in this situation, there are usually three common culprits: a broken dip tube, a buildup of sediment in your tank or a malfunctioning heating system.
How do I know if my thermal fuse is bad?
Multimeter Test
Remove the two wire leads from the thermal fuse and touch a multitester probe to each wire terminal on the fuse. If you get a reading of infinity, the fuse is fine. Any reading less than infinity indicates a triggered thermal fuse you will need to replace.
What causes a thermal fuse to fail?
A thermal fuse will blow when the temperature gets too high, not when it’s drawing too much current. When it blows, the dryer stops generating heat. It’s necessary to replace it before the dryer will run again.
Can you bypass a thermal fuse?
Locate and Bypass the Fuse
The thermal fuse will look like a thin strip of white plastic with a wire coming out of each end. In order to bypass the thermal fuse, use electrical tape to tape the two ends together. The thermal fuse will then be bypassed. Turn the dryer on to a heat cycle for no more than 90 seconds.
How do you check a thermostat on a gas water heater?
How to Test a Water Heater Thermostat
- Switch the water heater’s power off.
- Remove the access panels and insulation so you can access the thermostats/elements.
- Using a screwdriver, set the upper thermostat on high, and the lower thermostat on low, by turning the dial in the middle.
- Turn the power back on.
What is a high limit switch on a gas water heater?
The hot water heater reset is actually a high limit safety thermostat switch that disconnects the power to the water heater if the water exceeds a preset temperature. The temperature sensing button of the reset is in direct contact with the metal tank and senses water temperature through conduction.
How do you check a water heater reset switch?
The first thing you should check is the water heater’s reset switch, which is usually a red button on the upper thermostat of an electric water heater (you will need to remove the small panel to access it). If the button is lit up, it means the switch tripped and needs to be reset.
What is a thermal fuse made of?
The second type: Porcelain Tube Type Thermal Fuse
It is composed of an axisymmetric lead, a fusible alloy that can be melted at a specified temperature, a special compound to prevent its melting and oxidation, and a ceramic insulator. When the ambient temperature rises, the specific resin mixture begins to liquefy.
Why does my gas heater turn off by itself?
If your furnace keeps shutting off, it could be due to low airflow. There are several indirect issues that cause low airflow. Dirty Air Filters. If you don’t change your air filters often enough, the filters will become dirty and clogged, which means the heat exchanger retains heat and eventually causes it to overheat.
Contents