Voyager II - Negative Pressure Gas Valve Adjustment
The gas valve on 12.5 to 25 ton Voyager II staged gas units (negative pressure) can be adjusted out of the operational range for manifold pressure which will cause it to not open at all. If the manifold pressure is adjusted too high (clockwise), the gas valve will remain closed when energized. If the manifold pressure is adjusted too low (counterclockwise), the gas valve will remain closed when energized.
Follow the steps below to adjust the gas valve manifold pressure back into the operational range:
1. First make sure the supply pressure is in the range of 4.0"-14.0" of WC and is holding a steady pressure when energized. (Valve was factory set using a supply pressure of 7.0" WC)
2. Remove the slotted adjustment screw cover. See the picture below.
3. Back out the nylon adjustment screw by turning it counterclockwise until it is flush with the top of the adjustment screw port. See the pictures below.
4. Turn the adjustment screw clockwise until it is flush with the top of the adjustment screw port. The adjustment screw is fully counterclockwise at this point.
5.*** IMPORTANT STEP ***With the adjustment screw in the full counterclockwise position, turn the adjustment screw clockwise 10 full turns. 10 full turns will adjust the manifold pressure to approximately -0.23" WC with the supply pressure adjusted to 7.0" WC. This gets the manifold pressure back into a usable range.
6. Some minor adjustment to the gas valve may be necessary to achieve a correct manifold pressure of -0.2" WC.
Inlet Pressure Range = 4.0" - 14.0"
Manifold Pressure Range w/ Gas Valve Closed & Combusting fan running = -2.1 to -3.5
Manifold Pressure Range w/ Gas Valve Open & Combusting fan running = -0.2 +/-0.15"
Manifold Pressure should never be set positive
For more information on Voyager II Staged Gas Pressures, see:
Voyager 2 Staged Gas Manifold Pressure
For more information on Hot Surface Ignitor (HSI) Troubleshooting, see:
Hot Surface Ignitor (HSI) Troubleshooting and Specifications
For the Trane Power Burner manual, see:
Where do I get the Light Commercial Power Burner troubleshooting Guide?
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.