Pressure Switch Bulletin for Dual Fuel Gas Wall Heaters

Kozy World 2015-2016 Dual Fuel Gas Wall Heaters


Issue: In some natural gas installations the pilot may go out when control knob is released or when the burner cycles off/on. This is due to variations in incoming gas pressure around the country and a new built-in safety device in dual fuel heaters.


Background: In Feb 2015 an addenda to the ANSI standard ( Z721.11.2-2013) regarding dual fuel wall heaters took effect. All dual fuel wall heaters manufactured after Feb. 2015 are required to shut off within 5 minutes if the gas selector valve is not in the proper position. Based on the fact that natural gas is generally supplied at 5-8” Water Column (wc) and LP is generally supplied at 9-14” wc, a pressure sensing device (see illustration below) has been built into all Kozy World dual fuel wall heaters produced after Feb 2015. This pressure sensor is designed to turn off the heater if the device detects natural gas pressure exceeding 7” wc, or if the gas selector valve is set on LP, and LP pressure drops below 9” wc. There is a (± .05) variance within the device.

 

Pressure Switch

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Solution:
1. Check to ensure that the gas selector valve on the heater has been set to Natural Gas.
2. Ensure incoming gas pressure is set to 6-7” wc as outlined in the installation instructions
3. Your pressure switch may need to be adjusted.
4. Turn OFF gas at the equipment shut off valve.
5. Remove front cover by removing the (2) screws on each side of heater. Locate the pressure switch.

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6. Turn the Control Valve Knob to the "Pilot" position and Depress the knob for 5 seconds. Return the Control Valve Knob to the "OFF" position. (This step depressurizes the appliance's internal gas line.)
7. With a Philip's head screw driver turn the adjustment screw on the Pressure Switch clockwise 2 full revolutions.
8. Turn ON the gas at the "Equipment Shut Of Valve”
9. Light the unit as instructed in the Owner's Manual or Hang Tags located on the back of the unit and determine if this fixes the pilot outage problem. If the problem persists, turn the Control Valve Knob to the OFF position and repeat Steps 1 through 4 turning the pressure switch adjustment screw one revolution at a time until the appliance functions normally.
10. When the Pressure Switch set point is adjusted the appliance may not work properly if the unit is ever reinstalled on LP (Propane fuel).


NOTE: If this appliance is ever reinstalled using Propane (LP) fuel the pressure switch adjustment screw should be backed out completely, then reinstalled turning the screw in three full revolutions.