The Pentair Thermostatic Expansion Valve (474327Z) is the OEM replacement expansion valve for the UltraTemp Heat Pump Models 140 and 140HC.
⚠️ IMPORTANT: HEAT PUMP REFRIGERANT COMPONENT — PROFESSIONAL SERVICE REQUIRED
The thermostatic expansion valve is a refrigerant-circuit component. Gas and electrical heat pump components must be serviced by a licensed pool professional or qualified HVAC technician. Do not attempt to service refrigerant-side components without proper certification and EPA Section 608 refrigerant handling credentials.
The thermostatic expansion valve (TXV) meters refrigerant flow into the evaporator coil, regulating the rate of expansion to maintain optimal heat transfer efficiency across the refrigerant circuit. A failed or out-of-calibration TXV results in reduced heating output, compressor overload, or frost accumulation on the evaporator — symptoms that indicate the valve is no longer controlling refrigerant superheat correctly. This is the correct OEM replacement for UltraTemp 140 and 140HC heat pump models.
Specifications
| Pentair Part Number |
474327Z |
| Part Name |
Thermostatic Expansion Valve |
| Quantity Included |
Each |
Fits Into
| Brand |
Equipment Line |
Model / Part Number |
Notes |
| Pentair |
UltraTemp Heat Pump — UltraTemp Series |
140 |
Models 140, 140HC |
| Pentair |
UltraTemp Heat Pump — UltraTemp Series |
140HC |
Models 140, 140HC |
Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment's manual or on the original part itself before ordering.
Pro Tip
Before ordering, confirm your UltraTemp model number from the rating label on the unit — the 140 and 140HC share this valve, but verify the label matches one of these two models. TXV replacement requires recovering and recharging the refrigerant circuit; this work must be performed by a certified HVAC or pool heating technician with EPA Section 608 credentials. Do not attempt to replace this component without proper refrigerant handling equipment and certification.
