What impact would an undersized (1/4") liquid line have on a 2T 410a goodman heat pump's pressures in heat mode? I know it would cause elevated head pressure, but to what extent? (500+ psi w/ 65F OA & 70F IA) Indoor coil is clean, checked both pistons,changed out dryer, airflow is good and I'm Still getting a gradual increase in head pressure until it reaches 500- 600 psi. Runs normally in ac mode. Should I be looking a little more closely at the reversing valve? Any help would be greatly appreciated.