WPT Installation Manual
Document No. 910-00005-01, Rev 17
Page 17 of 19
Additional Troubleshooting
Symptoms
Possible Solution
The WPT does not
seem to build branch
pressure.
For 2 pipe WPTs:
1. First check that the rubber cap is firmly bottomed into port
stub as shown in Figure 18 below.
2. Remove the WPT from the Universal Wall Bracket.
3. Verify both main and branch lines are connected correctly. If
they are not attached correctly, reattach the line and check
the pressure again.
4. Remove the main line and verify that air is coming out. If
possible, measure the main pressure – this requires an
additional pressure gauge (not provided by Cypress)
connected to the main line.
5. Reconnect the main and remove the branch line connection.
6. Cover the branch port on the WPT completely with a finger.
7. Adjust the setpoint so it is at least 5 degrees above the
ambient temperature (for a direct acting stat) or 5 degrees
below the ambient temperature (for a reverse acting stat).
8. Check the branch pressure as described in section 3.3
9. If the pressure in the WPT is the same as the main pressure,
then there is a potential leak somewhere in the branch line
and there is nothing wrong with the WPT.
10. If the pressure in the WPT is not the same as the main
pressure, try swapping the WPT with another unit.
For 1 pipe WPTs:
1. Remove the WPT from the Universal Wall Bracket.
2. Verify that the branch line is connected correctly. If it is not
connected correctly, reattach the branch line and check the
pressure again.
3. Remove the branch line and verify that air is coming out. If
possible, measure the pressure – this requires an additional
pressure gauge (not provided by Cypress) connected to the
line. The pressure should build up to the main pressure.
Keep in mind that this may take a few minutes depending on
the length of tubing.
4. If the pressure does not build up, then there is a leak in the
branch line.
5. If the pressure does build up correctly, then try swapping the
WPT with another unit.
The WPT does not
seem to be controlling
correctly and/or is
making a loud hissing
sound
1. If this is a 2 pipe thermostat check that the rubber cap is
firmly bottomed into port stub as shown in Figure 18 below.
2. Check to see that the main and branch lines are connected
properly to the WPT. Refer to Figure 6 for proper connection.
3. If the lines are not properly connected, reattach the lines and
check the system again.
4. If the lines are properly connected, try swapping the WPT
with another unit.
5. If the branch and main lines are swapped, the WPT was
installed incorrectly and may be damaged.
