Why would a trap that seems to be discharging water experience problems when connected to the return line?
1. If this is experienced, there may be a problem in the return line, back pressure may be diminishing the capacity of the trap:
1. Return line may be too small. If this were the case the trap would be hot.
2. Other traps on the line may be blowing steam. This too would cause the trap to be hot.
3. There may be a blockage in the return line. The trap would be hot.
4. There may be an excessive vacuum in the return line. If this were the case the trap would be cold.
The atmospheric vent in condensate receiver may be plugged. The trap could either be hot or cold.