The
thermocouple
is connected to the gas valve that leads to the pilot light and has a sensor that detects heat from the burning flame. If the flame goes out or is burning weakly, the thermocouple shuts off the gas supply to the pilot light in order to prevent gas from leaking into other parts of your furnace.
Where is safety switch on furnace?
The limit switch is a safety control switch located
on the furnace just below the plenum
. If the plenum gets too hot, the limit switch shuts off the burner. It also shuts off the blower when the temperature drops to a certain level after the burner has shut off.
What is a safety device on a gas fired furnace?
Thermocouple or Mercury Flame Sensor
This critical device is designed to turn off the gas supply to the furnace when it detects that the pilot light is off. This prevents unburned gas from building up inside the furnace and leaking out into your home, creating a highly dangerous situation.
What is a safety switch on a furnace?
The blower door safety switch is a simple plunger that,
when opened, cuts the power to your gas-fired furnace
.
How many safeties does a furnace have?
Three Furnace Safety
Switches
In the typical furnace, there are three different safety mechanisms that all have to be working properly in order for the furnace to run.
Can gas furnaces explode?
Although it is possible for a gas furnace to either catch fire or explode, it's highly unlikely
. If there is a danger of this happening, the furnace will usually simply shut off—as it's designed to. … If you've got a good furnace and take care of it, you won't have to worry about explosions or fires.
How safe are gas furnaces?
Gas furnaces
can develop leaks and cracks over time
that allow deadly carbon monoxide gas to escape into the home. Older gas furnaces pose an even greater risk. And because carbon monoxide is colorless and odorless, it is impossible to detect until you start feeling symptoms.
How do I know if my furnace door switch is bad?
If the switch is causing the furnace to shut down, you'll get an
“OL” reading when the plunger is depressed
. If you get a zero reading when the switch is extended, that's just as bad because it means the switch isn't giving the protection it's supposed to give. Either way, it needs to be replaced.
How does a furnace door switch work?
The blower door switch
kills power to the furnace when the blower door is removed
. … Since the controls and blower are in that compartment, it is impossible to work on the electrical controls with the blower door removed if you do not jump out or physically disable the door switch.
What types of safety switches are used on gas furnace?
- Limit switch. A limit switch is essentially a thermometer that measures the temperature of the space surrounding your furnace's combustion chamber. …
- Thermocouple. …
- Mercury flame sensor. …
- Air pressure switch. …
- Carbon monoxide detectors.
Should the emergency oil burner switch be on or off?
The switch
should be in the ON position
. The emergency shutoff switch looks just like a light switch, so it may have been accidentally turned off. That can happen quite often. Check your electrical box: Look for blown fuses or any tripped circuit breakers.
Should a furnace be on its own circuit?
According to building codes,
a furnace must be supplied by a dedicated circuit
, meaning the circuit cannot supply power to anything other than the furnace. … It ensures that power to the furnace stays disconnected even if someone unwittingly turns on the circuit breaker.
What is the precautions to be taken while working in furnace?
Lint and dust causes hazards around your furnace
. You can avoid dust build-up by vacuuming inside and around your furnace every month. If you neglect to vacuum, the dust may become a fire hazard. You can refer to your maintenance instructions for more details on cleaning.
Is it safe to turn off furnace switch?
Switch off the furnace's main gas supply
. Make sure you turn off the supply to the furnace, not the house, as you'll still want hot water during the summer. Check the carbon monoxide detector to ensure it is running properly. Enjoy a cool summer knowing your furnace is off and not wasting money.
Can you have a furnace in a garage?
Garages:
Many furnaces are placed in garages
. … However, in homes with a larger laundry room, the furnace may be placed there. Attics: In homes with limited space, the furnace can be installed in the attic.
