A compressor unit for heating and sanitizing water for human use including a combustion housing defining a combustion chamber. A heat exchanger is partially supported in the combustion chamber and configured to heat water. An igniter ignites fuel and air in the combustion chamber. The compressor unit further includes a compression housing defining a compression chamber in fluid communication with the combustion chamber. An intake valve is configured to meter air into the compression chamber. An oscillation plate is supported in the compression chamber and movable between first and second positions wherein movement of the oscillation plate between the two positions compresses air directed toward the combustion chamber. A sealed case around a heat fan and an attached exhaust pipe contain exhaust gasses after a release valve. A case for a crankshaft contains lubrication and is sealed with a lid similar to an oil pan.