Tjernlund WHK-2 Millivolt Interlock Kit (Discontinued - Not Compatible with UC1) 8504026 Rev 8 09/98 - Manual (Page 12)

WHK-2 TROUBLESHOOTING
10
NOTE: All troubleshooting diagrams below are for a Furnace or Boiler & Water Heater common vented using a WHK-2 and HSUL,
GPAK-J,1 Series Power Venter or Draft Inducer with 950-1040 24/115 VAC Relay.
SYMPTOM 1: HSUL, GPAK - SERIES POWER VENTER OR DRAFT INDUCER OPERATES CONTINUOUSLY. BEFORE
CONTINUING, THE VENTER SHOULD BE OPERATING WITH NEITHER APPLIANCE CALLING FOR HEAT.
Check wiring inside Venter electrical box from WHK-2 metal conduit.
1) Gray from WHK-2 should be connected to thick Black Venter motor
wire and terminal 3 or 4 on Venter Relay.
2) Black from WHK-2 should be connected to thin Black wire on Relay.
3) White from WHK-2 should be connected to White Venter motor wire.
Yes
Yes
Yes
Yes Yes
Yes
Yes No
No
No
No
No
No
No
With the Venter Operating, remove the Blue wire from WHK-2 Relay/Timer. The Venter should
shut off within 10 minutes.
Reconnect the Blue wire on the WHK-2 Relay/Timer, the Venter
should start operation again. Remove the Blue wire from Water
Heater Gas Pressure Switch. The Venter should shut off within 10
minutes. With the Blue wire still removed from WHK-2 Relay/Timer and
the Venter operating, remove the thin Black wire from the
Venter Relay. The Venter should shut off within 10 minutes.
Replace WHK-2
Relay/Timer
Part #950-1067 With the Blue and thin Black
wires still removed from the
previous step, remove the
Gray and Blue wires from
the Venter Relay. Check for
continuity between the
Venter Relay terminals
which the Gray and thin
Black wires were connected
to.
Replace Venter
Relay. Part
#950-1040 The Venter is not wired to the
Furnace/Boiler correctly.
Rewire per the WHK-2
instructions.
Remove all tubing from Gas Pressure
Switch and check Switch for continuity.
Replace WHK-2
Control Cable. Part
#950-2060.
Replace WHK-2 Gas
Pressure Switch.
Part #950-2080. Check WHK-2 Gas
Pressure Switch tubing
for blockage.
Repair or replace
tubing. Check Water Heater
Pressure Tap Port for
pressure with the burner
off.
Contact Water
heater manufacturer
for assistance.
Contact Tjernlund Products,
Inc. at 1-800-255-4208 for
assistance.
The following guide is intended to be used if a problem occurs during the use of the WHK-2 and HSUL, GPAK-J,1 Series Power
Venter or Draft Inducer with 950-1040 24/115 VAC Relay. At several steps throughout the guide you will be required to measure voltage.
Extreme caution must be exercised to prevent injury. If you are unable to determine the defective part with the use of this guide,
call your Tjernlund distributor or Tjernlund Products direct at 1-800-255-4208 for further assistance.