Tjernlund WHK-2 Millivolt Interlock Kit (Discontinued - Not Compatible with UC1) 8504026 Rev 8 09/98 - Manual (Page 11)

OPERATION CIRCUIT CHECK
1. Place water heater in operation. A. The Power Venter should operate.
2. Turn gas pilot knob to “pilot”. B. The Power Venter should continue to operate for approximately 1 minute. The length of the
post-purge cycle can be varied by adjusting the post purge control. See “Post Purge Timer Adjustment” on bottom of page.
3. Repeat steps #1 and #2 to assure proper operation.
SAFETY INTERLOCK TEST
1. Remove the BLUE lead from the normally open contact of the Gas Pressure Switch. (This will disable the Power Venter).
2. Adjust the heater’s thermostat or run hot water until full burner operation occurs.
3. Within 3 minutes the Linear Limit spillage sensing switch circuit should disrupt power to the Gas Solenoid Valve, stopping the
supply of gas to water heater.
4. IMPORTANT: Wait 5 minutes and push the reset button on the Linear Limit spillage sensing switch.
5. Reconnect the BLUE lead to the normally open terminal of the Gas Pressure Switch.
6. Re-light pilot following the water heater manufacturer’s instructions.
7. Extinguish the pilot with the burner off. Determine, after 3 minutes that there is no gas flow to the main burner. If gas flow to the
main burner is detected, replace the water heater gas valve immediately.
COMBUSTION AIR TEST
The Linear Limit spillage sensing switch is designed to alert the user to a potentially hazardous condition. It is not designed to, and
cannot replace, regular vent system inspection, appliance servicing and combustion testing. DO NOT USE IT AS A SUBSTITUTE
FOR PROFESSIONAL APPLIANCE MAINTENANCE.
1. Close all doors and windows of the building. If appliance is installed in utility room or closet, close the entrance door to this room.
Close fireplace dampers.
2. Turn on clothes dryer. Turn on all exhaust fans, such as range hoods, bathroom exhausts and whole house fans to maximum
speeds.
3. Following the water heater manufacturer's instructions, place the appliance in operation, set thermostat for continuous operation.
4. Allow fans and appliance to operate for 5 minutes.
5. Tripping of the Linear Limit spillage sensing switch during 5 minute appliance operation indicates an unsafe operating condition.
Turn off fuel supply to appliance and DO NOT OPERATE UNTIL UNSAFE VENTING CONDITION IS INVESTIGATED BY
A PROFESSIONAL CONTRACTOR OR UTILITY SERVICE PERSONNEL.
6. Return all windows, doors and fans to their previous conditions of use.
POST PURGE TIMER ADJUSTMENT
1. Disrupt 115 VAC power to the Power Venter.
2. Loosen the two screws and remove junction box cover.
3. The post purge timer is marked “adjustable delay control”. The adjustment is made by turning the small slotted screw. Turn it
counter clockwise to increase the delay, clockwise to decrease the delay.
(Nominal adjustment range is 1 to 10 minutes) NOTE: Do not overturn adjustment screw on Relay/Timer. This will damage
Relay/Timer and void warranty.
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