The furnace gas valve operates by
electromagnets
. The primary valve — also known as the safety valve — supplies gas to the pilot light. The second valve — also known as the main valve — allows gas to flow to the burner trays. The thermocouple (or thermopile) generates the power holds the safety valve open.
How do I know if my gas control valve is bad?
If
the burner stays on, turn the gas supply off and replace the gas valve
. If the pilot is lit, you have a tank of cold water, the thermostat turned up and the burner does not fire up, either the burner orifice is clogged or the water heater gas valve is bad.
How do gas valve thermocouples work?
The thermocouple in a gas furnace is
designed to keep the gas valve open through its electric voltage
. If the pilot light goes out, the loss in heat causes the voltage between the two pieces of metal to drop, and this shuts the valve and reduces the combustion risk.
How do you test a gas valve on a furnace?
- Turn off the furnace at the wall control. …
- Take out the bolts in the service panel on the side of the furnace using a nut driver. …
- Pull the wires off the gas valve terminals. …
- Turn the test control on the multimeter to “mV,” which stands for millivolt.
What is a gas valve control used for?
Gas valves are flow control devices used
to handle and control the flow of gases such as liquefied petroleum, oxygen, and sour and natural gas
. They are available in a variety of metal or plastic materials that are compatible with the media controlled and pressure requirements.
What happens when gas valve goes bad?
Gas flows from your supply tank into your furnace through the gas valve. If the valve is faulty,
it could allow gas to leak out into the surrounding environment
. Most modern furnaces have built-in safety features, but leaks can still occur.
Can you fix a gas valve?
The gas valve cannot be repaired in the field.
Only the gas valve manufacturer or someone certified by the manufacturer of the gas valve can make repairs
. Then re-certifying the safety of the gas valve.
How do I know if my thermocouple is bad?
If you can't get the flame to light at all, and you're sure the gas is on, there's probably an obstruction in the pilot tube.
If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds
, that's the sign of a thermocouple malfunction.
What does TP stand for on gas valve?
TP =
Temperature and Pressure
.
Water heater
TP valve is a safety device that prevents water heater from exploding.
How does a standing pilot gas valve work?
A standing pilot gas furnace uses a
small, continuously burning flame as a source of ignition for
the main gas burner. … When the thermostat calls for heat and prompts the main gas valve to turn on, the pilot light ignites the larger flow of gas to the burner from the main supply.
How do I know if my gas valve is open?
Gas shutoff valves
When the long side of the nub or handle is parallel to the incoming gas line, it's open and the gas is flowing
. When it's turned a quarter turn, perpendicular to the incoming pipe, it's closed.
Can a furnace gas valve be repaired?
In some instances you can repair a gas valve on a furnace depending on what is causing it to not work properly. However, repairing your gas valve is not usually the most cost effective option since it can be just as expensive to have your gas valve repaired as it would be to have your entire gas valve replaced.
How do you free up a stuck gas valve?
Take an
adjustable wrench
( crescent wrench ) and adjust it so it fits over the handle, The longer the better for leverage. Have a helper hold the pipe assembly from moving with the pipe wrench and then try to gently get the valve handle to move, use caution and just try to move it a little.
What type of valve is used for natural gas?
A butterfly valve
is employed to regulate, stop, and start the flow. This quarter-turn rotary motion valve rotates the handle at 90°, which can completely close as well as a start. It makes it able to use in the oil and gas industry.
