A few weeks ago we turned on our spa and heard a loud pop noise. We inspected the heater to find that the blower had "blown up." We replaced the blower but the heater will not ignite. We reset the system by turning off the power...still nothing. The display shows the SW Pressure and Thermostat are on, but the heater light does not come on. We do not smell gas, and the blower runs fine. The system then shows the E04 error code for ignition failure.