Troubleshooting - Johnson Controls - LIT-12014272 - Valve - Venturi Valve

Venturi Air Valve with UVM1000 Installation Guide

Product name
Venturi Valve
Document type
Installation Guide
Document number
LIT-12014272
Revision date
2023-03-10

Use the following information as a guide for potential resolution of a site issue.

Table 1. Troubleshooting
Problem Causes Solution

Fume hood monitor in alarm; Room pressurization problem.

Low static pressure across valve (<0.6 in. W.C; 150 Pa)

  • Too many sashes open at one time
  • Sash open beyond maximum allowable position
  • Blocked or kinked pressure switch tubing
  • Contact HVAC service maintenance contractor to inspect, verify and correct.
  • Review operator sash movement.
  • Incorrect valve position
  • Valve is not responding to input signal
  • Loss of pneumatics
  • Mechanical linkage is disconnected
  • Loss of power or electrical control signal
  • Broken sash cable
  • Monitor calibrated incorrectly
  • Incorrect wiring terminations

Contact HVAC service maintenance contractor to inspect,

verify and correct.

Temperature control issues
  • Reheat system issues
  • Thermostat malfunction
  • Air handler malfunction
  • Water valve response issues
Contact HVAC service maintenance contractor to inspect, verify and correct.
Valve banging
  • Fluctuation in pressure that is out of acceptable design range
  • Lack of bypass damper control
  • Slow response to duct pressure control
  • Adjust bypass damper control.
  • Install fast acting actuators; flow probes and VAV control; integrate into stand alone lab control.
  • Contact HVAC service maintenance contractor for inspection, verification and correction.
Note: Exposing any Venturi Valve to excessive pressures that are outside of the range of specification may require the valve to be recalibrated and recertified at factory; potential damage to the valve may also occur.

Monitor indicates normal operation, but actual face velocity or flow is measured high or low.

Low or high static pressure
  • Verify at least 0.6 in. W.C (150 Pa) across valve.
  • Connect a Magnahelic gauge across the valve taps.
  • For hood valves, check voltage at TB-16 at fume hood monitor.

    (>10 V=low static)