Question

A (TXV) thermostatic expansion valve system blows cold air for five minutes and then goes warm. Technician A says this condition is caused by a low refrigerant charge. Technician B says this condition is caused by moisture in the system. Who is correct?

A. Technician A
B. Technician B
C. Both A and B
D. Neither A or B

Answer 1

Both Technician A and Technician B are correct; a TXV system blowing cold air and then going warm could be due to a low refrigerant charge or moisture in the system, which causes ice blockages.

Step-by-step explanation:

When a thermostatic expansion valve (TXV) system blows cold air for a short period and then goes warm, it could be indicative of issues like a low refrigerant charge or moisture in the system. Technician A is correct in stating that a low refrigerant charge could cause the unit to blow cold air initially until the charge drops too low to maintain cooling. Technician B suggests that moisture in the system could be creating ice blockages, which also could result in brief cooling followed by warm air output. Therefore, the accurate answer is C. Both A and B because both conditions could cause the described symptoms within a TXV system.