Arrived onsite and ran gold membership Cleaned fins on exterior of heat pump and wiped excess algae and grass away from unit. Checked current draws on compressor and outdoor fan motor. Outdoor unit appears to be functioning well. Ran heating system through cooling and heating and found both temperature splits to be within tolerance. Ran system through emergency back up heat and had a temperature split of approximately 50F with no CO. This temperature split seemed high. Checked filter and found filter to be completely saturated. This is believed to have caused the high differences in temperature across the heat exchanger. Blower and inducer motor appear to be pulling good current within appropriate tolerance. Air scrubbed bulb is believed to be burn out. Voltage is present to the air scrubber but operation light is not on. Customer had stated that she runs the fan setting to ON to circulate air through system. This is believed to have burnt bulb out. CPI recommends re