Sensor Resistance All of York's sensors are the same resistance - 10K Ohm. Temp Ohms Temp Ohms Temp Ohms Temp Ohms 0 85,371 50 19,896 100 5,827 150 2,041 5 75,230 55 17,434 105 5,208 155 1,854 10 62,499 60 15,310 110 ...

CHECKING SUPERHEAT What is superheat? Superheat refers to the number of degrees a vapor is above its saturation temperature (boiling point) at a particular pressure. How do I measure superheat? Superheat is determined by taking the low side (suction) pressure gauge reading, converting that...

CHECKING SUBCOOLING Expansion valve systems are normally charged by using the subcooling method. Liquid sub-cooling is required so that you have only liquid entering the expansion valve with no bubbles present. Vapor bubbles present in the refrigerant will cause low refrigerant flow. Low...

LIQUID LINE SIGHT GLASS A liquid line sight glass allows for quick, visual confirmation of refrigerant charge when the metering device is an expansion valve. Cooling Mode In the cooling mode, refrigerant is pressurized and cooled in the condenser. With adequate pressure and cooling the...

THERMAL EXPANSION VALVE A thermal expansion valve (often abbreviated as TEV, TXV, or TX valve) is a component in refrigeration and air conditioning systems that controls the amount of refrigerant flow into the coil thereby controlling the superheating at the outlet of the evaporator. Thermal...

Make: All Model or Series: All Type: Horizontal Problem Description: New unit too noisy. Observed Symptoms: New unit installed in crawlspace. Supported from floor joists with all-thread and uni-strut. No vibration isolation between unit and uni-strut. Solution: Installed foam...

DUCT SIZING: Improperly-sized ductwork can cause multiple heating and cooling performance and service issues. Under-Sized Ductwork Symptoms Inadequate airflow Excessive noise Cooling freeze-ups Heat Pump high pressure Furnace limit trips Pre-mature motor failures Over-Sized...

Troubleshooting a Low Voltage Short Indications: A Blown Low Voltage Fuse or a Bad Transformer 1. Prepare to Diagnose Short Turn off line-voltage power to the air handler or furnace. Install a resettable low voltage breaker (if not already on the transformer). At the furnace or air...

Belt-Drive Blower Speed Adjustment The blower speed and motor amperage on a belt-drive blower motor can be adjusted by changing the pulley (or sheave) size. Motor Pulley Increasing the size of the motor pulley = More Speed and Higher Amperage Decreasing the size of the motor pulley = Less...

A/C FREEZING-UP SYMPTOMS: Visible Ice On the Coil or Lineset Visible Ice at Outdoor Unit No Airflow from Registers WHAT THE CUSTOMER SHOULD DO: If the customer notices ice on the coil cabinet, on the lineset, or in the outdoor unit they should do the following: 1. Turn the System Off ...