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How to turn off electricity & oil or gas fuel to heating equipment. This article describes how to turn off heating equipment in an emergency or if the equipment does not turn off in response to normal thermostat controls.
We describe first turning off electrical power and next turning off oil or gas fuel supply to the equipment. You may use these same controls when shutting down a building's HVAC equipment in an emergency or under other conditions. We include important safety warnings when performing heating equipment shutdown.
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The places to do this are at the Emergency OFF electrical switch (usually the switch plate is red) located outside of the boiler or furnace room, usually on a wall near a doorway. In many homes this switch is located at the top of a basement stairwell; Often a second electrical switch is also located right at the heating equipment.
The heating equipment should STOP immediately.
In an emergency, if turning off electrical power does not stop an oil or gas fired heating unit, and provided that you can safely approach the unit (there is no fire or smoke) you should turn off both electrical power AND the fuel supply to the equipment. Below in this article we explain how to turn off the heating oil or gas fuel supply to heating equipment.
But if the building is on fire or smoke-filled, slowing down to look for equipment switches or approaching equipment that is glowing red, smoking, on fire, or otherwise scary is dangerous and should not be attempted. Instead you should get out of the building and call for help.
Watch out: If you cannot safely turn off heating equipment in an emergency you should immediately get everyone outside of the building and then from another location call your local fire department for emergency assistance.
Then call your heating or air conditioning service company for further diagnosis and repair help.
Details about this switch are at ELECTRICAL POWER SWITCH FOR HEAT
Immediate LP or natural gas safety hazards: if there is evidence of an LP or natural gas leak at a building, gas odors, for example, you should:
Watch out: Don't cycle the heating or cooling equipment electrical ON and OFF rapidly using the electrical power switch or any other control. For heat, wait at least five minutes between on-off cycles; for cooling wait at least fifteen minutes to minimize the risk of equipment damage.
How to Turn Off Fuel Supply to Oil or Gas Fired Heaters
What if Oil or Gas Fired Boiler or Furnace Keeps Running Even with Power OFF?
Watch out: oil or gas fired hot water or steam heating equipment may fail to shut down even if electrical power to the equipment is turned off.
We found this situation at an old oil fired heating boiler in Poughkeepsie, New York. Even after turning electrical power off we observed that a smoky flame continued indefinitely at the oil burner. It was pretty un-nerving to see that oil burner continue to fire away even after we had turned electrical power off. The oil burner motor stopped, but the fire chamber was red hot, enough that as oil continued to feed out through the oil burner nozzle the fire just continued.
The problem was a failed check valve in the oil burner's fuel unit, combined with gravity-fed oil to the heating system.
Turning Off the Oil Line Valve - the OSV or Oil Safety Valve
For oil fired heating equipment if the oil safety valve is turned fully clockwise (right to left) it is moved to its closed position and oil cannot flow (photo below).
This valve includes a fusible link or stem that is designed to melt and thus allow a spring to snap the valve shut in the event of a fire.
There is so much confusion about which way to turn this valve that we've gone over it ad nauseum at OIL LINE SAFETY VALVE TURN DIRECTION to OPEN or SHUT. Details about oil line shutoff valves, oil safety valves or OSVs are at OIL LINE SAFETY VALVES, OSVs.
Turning Off the LP or Natural Gas Line Valve
For gas fired heating equipment, codes require a shutoff valve outside of the equipment cabinet; the valve is usually a lever, in which case if the lever is at right angles to the piping the valve is OFF and gas flow will stop. In our photo below the red gas valve control lever is parallel to the LP Gas line and thus is in the OPEN position - allowing gas to flow.
If the gas valve is a round handle that looks a bit like a water shutoff valve, turning the valve fully clockwise (right to left) is off, just as with water valves.
In our photo above the gray colored handle at the right side of the image is the main gas valve on this LP gas tank. To CLOSE this gas valve turn it all the way in or clockwise. Don't be confused by that yellow cap - that's used by the LP gas delivery driver to fill the LP tank.
Above we show a gas meter located outside the building; just about every gas meter installation will include a gas line shutoff valve on the incoming gas line. The gas company tells us not to touch this valve, but honestly, in an emergency we've seen emergency workers not hesitate to use a tool to carefully close the valve.
Watch out: never force a stuck oil or gas fuel valve. If you break it and cause a leak you've probably caused a big catastrophe, possibly an explosion or fire. We can understand the gas company's position in this matter.
Details about gas shutoff valves are at GAS SHUTOFF VALVES or select a topic from the More Reading links shown below.
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