Air compressor oil heater

[Mr Mike Mills]

Has anyone used a frost plug heater on an air compressor? I am wondering if a frost plug heater could be screwed into the oil drain plug to keep oil warm.

Thanks Mike

[Bill Dufour]

Only if it doesn't stick in too far and get hit by moving parts. A cartridge heater will have a smaller npt mount. You could use a goldenrod heater, pipe heat tape the crankcase or stick a light bulb in the ac closet. I think you would want to heat up the cylinder as well. On many compressors there is plenty of room under them and above the tank to put in a heater of some kind. How many watts is a reptile hot rock? There is no need to heat it unless you will be using it that day. Any moisture left in water traps etc could freeze and break stuff.
Bill D

[Stan Coryell]

I have not. I don't see any reason it wouldn't work. As far as another option, you might try synthetic oil. They also make magnetic block heaters and a HVAC supply would have a "compressor crankcase heater". The crankcase heater is sort of a blanket with springs to hold it on and a thermostat

[Andy D Jones]

I'm confused... Frost plugs I have seen are (tight) friction fit, not threaded, so they pop out when the coolant freezes, thus relieving pressure, and avoiding further damage.

Does a frost plug heater replace the frost plug, or does it screw into a special frost plug?

-- Andy - Arlington TX (where I haven't worried about freezing temperatures inside my attached garage since the early 90's)

[Stan Coryell]

It replaces the plug. It's an expanding rubber doohickey.

[Bill Dufour]

There should not be any core holes in a compressor casting that will fit a so called "frost plug". The so called "frost plug" is just a way to seal off a hole that has to be there to support the cores that form the internal passages in the casting. After the casting is cooled all the sand from the cores has to be cleaned out through those holes. They do almost nothing to protect from frozen water in the block. That is not the reason for those core plugs.
That is why I suggested a cartridge heater. It fits a much smaller hole.
Bill D