Heat Pump Pool Heater Start-Up Pressure Spike Eliminator

A heat pump water heater comprising:

• a refrigerant circuit having a compressor, a condenser, an expansion valve and an evaporator operatively interconnected in refrigerant tubing in a manner such that during operation of said heat pump apparatus refrigerant in said refrigerant tubing sequentially flows outwardly from said compressor, through said condenser, through said expansion valve, through said evaporator and then back into said compressor, said condenser including a housing portion having a water inlet and a water outlet, and a coiled portion of said refrigerant tubing extending through the interior of said housing portion;
• a hollow wall structure defining a cavity extending around a first portion of said refrigerant tubing disposed between said compressor and said condenser;
• and
• a transfer tube having an inlet end directly coupled to a second portion of said refrigerant tubing disposed between said condenser and said expansion valve, and an outlet end connected to said hollow wall structure, said transfer tube communicating said cavity with the interior of said second portion of said refrigerant tubing and permitting refrigerant within said second portion of said refrigerant tubing to migrate into said cavity during off periods of said heat pump pool heater.