Raypak 12 Ton TX Valve for R8350/P8350 Heat Pump Pool Heater, H000077

The Raypak H000077 is the 12 ton thermal expansion valve for the R8350 and P8350 heat pump pool heaters. It is the genuine Raypak part for that circuit.

What the valve does

A heat pump moves heat out of the air and into the pool water. The expansion valve sits between the condenser and the evaporator and meters refrigerant into the coil at the rate the load calls for. Get that flow wrong and everything downstream suffers, because the compressor sees the wrong suction conditions and the coil cannot absorb heat properly.

Symptoms of a failed valve

The usual signs are a unit that runs for long stretches without warming the water, a coil that frosts over in mild weather, or suction pressures that will not settle. Those symptoms overlap with a low charge and with airflow problems, so the diagnosis should be confirmed on gauges before the valve is condemned.

Fitting

Replacement requires recovering the refrigerant, brazing the new valve in and recharging the system. It is a licensed technician job, not a pad side repair.