Why is it not always a good idea to install a gauge set and check ...

[berenicecastro]

Why is it not always a good idea to install a gauge set and check the system pressure on every system?
 
  What will be an ideal response?

Question 2

Explain the difference between the back seated position and the front seated position on manual stem service valves.
 
  What will be an ideal response?

[TheNamesImani]

Answer to Question 1

Some units have a critical charge and installing gauges can lose enough refrigerant to make the system undercharged.

Answer to Question 2

When the valve is back seated, the service port is closed and the center port is open to the line port. When the valve is front seated, the line port is closed and the center port is open to the service port.

[berenicecastro]

Thanks for the timely response, appreciate it

[shailee]

Gracias!