Table of Contents
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 does a gas valve 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.
How do I know if my gas valve is bad?
If the gas valve is stuck or otherwise malfunctioning, your furnace may shut down completely or just stop delivering warm air. There are other issues that may cause the same symptom, so you need an experienced technician to diagnose the problem and apply the proper repair.
How does a gas boiler gas valve work?
A boiler gas valve controls the flow of gas to the pilot light and burner. It’s controlled by an electrical signal coming from the printed circuit board (PCB). The PCB detects that the fan is operational, ready to expel dangerous flue gases via the flue. The gas valve opens to allow fuel into the burner and pilot light.
How do you test a gas valve?
How to Check the Furnace Gas Valve With a Multimeter 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.
How do you know if a valve is open or closed?
Ball valves are perhaps the easiest valve to see if they are open or closed. If the handle on top is parallel to the valve, it’s open. Likewise, if the handle is perpendicular to the top, the valve is closed.
How many valves are in a gas valve?
How A Furnace Gas Valve Works. There are essentially two valves that make up your furnace’s gas valve, and they are positioned in series, or one after the other. The furnace gas valve operates by electromagnets. The primary valve — also known as the safety valve — supplies gas to the pilot light.
What causes gas valve failure?
The valve itself may have simply worn out or may be damaged due to basement seepage or submersion. Alternately, one of the electronic gas ignition components or a glitch in the safety circuit may be to blame. If your furnace has a standing pilot light, the thermocouple could be worn out.
Can a gas valve be repaired?
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. This also applies to gas valves that have been submerged underwater due to flooding.
How do you bleed a gas valve?
While pressing the valve control knob in, press the igniter button repeatedly until the pilot ignites. This could take anywhere from one to 10 minutes to bleed air out of the lines as the gas starts to flow. Once the pilot is lit, continue to press the valve knob inward for 30 seconds before releasing it.
How do I free a stuck gas valve?
Heres how; First, turn off the gas in the house so you don’t blow yourself up or cause a disaster, loosen the bottom nut, tap the bottom of the plug upward to loosen the tapered plug, remove the tapered plug, lubricate with a special gas valve grease , and re-install the plug, job done.
What does gas control valve failure mean?
On a gas water heater, the gas control valve contains the thermostat and pilot light controls. Water heater problems that may be caused by the gas control valve include a faulty hot water heater thermostat, faulty gas valve, pilot light that won’t light, and tripped heat limiter.
How do you reset the gas valve on a furnace?
Follow these steps to reset your gas furnace: Turn the circuit breaker off and switch the furnace power button off too. Access the pilot light by removing the access panel. Turn the gas control valve off and let the gas dissipate for five minutes before turning it back on in order to prevent a fire hazard.
Where should a gas shut off valve be located?
The gas meter and gas service shutoff valve is usually located on the side or in front of the building. If the building has a breezeway, it could be located there.
Which way do you turn a valve to close it?
When it comes to which way you should turn the valve, keep in mind the old saying “righty tighty, lefty loosey.” In other words, turning a valve clockwise, or to the right, will restrict the flow of water while turning it counterclockwise, or to the left, will allow water to flow.
Which shut off valves should be open and closed?
The rear shut-off valves should be open. All shut-off valves should be in the open position, except the rear shut-off valves.
How long should a gas valve last?
Gas Valves are routinely checked for 100,000 cycles and are used in equipment that have approximately 15 years life expectancy.
Can a gas valve break?
Although relatively rare, gas valves can fail causing a fire or explosion. Gas valves can fail from a variety of causes including contamina- tion, product deficiency, and misuse.
How much does it cost to replace a gas valve?
Furnace gas valve prices are $75 to $300 for the part alone or up to $600 for original manufacturer parts (OEM). Gas valve replacement labor costs $125 to $500.Furnace gas valve replacement cost. National average cost $500 Minimum cost $125 Maximum cost $1,000 Average cost range $200 to $800.
