FIX. This is a quick fix and NOT a permanent solution. The switch
is a SAFETY device and should not be tampered with or bypassed. Locate the pressure switch
. Most look like the shape and size of a pocket watch, usually black plastic or silver metal. Remove and label the hoses and wires connected to the switch
. Remove the sheet metal screws and remove the switch
from the heater. Remove the mini orifice tube from the intake side of the switch
with fingernail or small screwdriver. Be certain there are NO air restrictions by blowing and sucking into either side. As a last resort, an aerosol cleaner such as a automotive carburetor cleaner may be used. Be certain any cleaner used states on the can that it is "sensor safe." DO NOT use brake cleaner or any other electrical cleaner unless it states "sensor safe!"
Wait for the cleaner to dry and install
the orifice tube and installation is reverse.