Dual heater system for spray dispenser

A mobile spray dispenser comprising:

• a fluid reservoir;
• a motorized pump disposed to pump fluid from the fluid reservoir;
• a sprayer
• a fluid circulation system capable of operating in a plurality of alternative modes, the modes comprising:
• wherein the motorized pump has a high-pressure spray mode wherein fluid from the fluid reservoir is provided to the sprayer;
• and
• wherein the motorized pump has a low-pressure recirculation mode wherein fluid is circulated to a return hose back to the reservoir via the sprayer, and wherein the motorized pump draws lower power in the low-pressure recirculation mode than in the high-pressure spray mode;
• a heating unit disposed within the fluid circulation system to heat the fluid to a target temperature, the heating unit comprising:
• a primary heater configured to be active during both the high-pressure spray mode and the low-pressure recirculation mode;
• and
• a boost heater in fluid series with the primary heater and configured to be active only during the low-pressure recirculation mode;
• and
• wherein during both the high-pressure spray mode and the low-pressure spray mode the fluid flows from the motorized pump to the boost heater to the primary heater and the sprayer.