TJERNLUND WHK2 MILLIVOLT APPLIANCE INTERLOCK INST. (NOT COMPATIBLE WITH UC1) 8504026 REV A 0600 User Manual

©2004 TJERNLUND PRODUCTS, INC. ALL RIGHTS RESERVED P/N: 8505022

TJERNLUND PRODUCTS, INC.

1601 Ninth Street • White Bear Lake, MN 55110-6794
PHONE [phone] • [phone] • FAX [phone]
Visit our web site • www.tjernlund.com

Qty (1) gas pressure switch Qty (1) 1/8-NPT pipe plug
Qty (1) 1/8-NPT black pipe tee Qty (2) brass 1/8-NPT male x ¼" compression fitting (Only (1) included in 950-2080 kit)
Qty (2) #10 x ½" self-tapping screws Qty (1) section of ¼" outside diam. aluminum tubing (Not included in 950-2080 kit)

NEW STYLE GAS PRESSURE SWITCH INSTALLATION

The gas pressure switch is mounted on the casing of the water heater adjacent to the heater's thermostat/gas control valve. It
should be mounted close enough so that the supplied 1/4" tubing will reach from the gas pressure switch fitting to the thermo­stat/gas valve pressure tap port. The two provided screws are self-tapping and drilling. The screws do not require the use of a
drill and their 1/2" length assures that the inner tank will not be penetrated.

1. Mount the gas pressure switch by securing it to the heater casing with a screw in each of the two mounting holes.

IMPORTANT: Mount gas pressure switch so that diaphragm is in a VERTICAL

position, (See New Switch Diagram).

2. Install the supplied 1/8"-NPT pipe plug to the 90

o

port of the supplied 1/8-NPT black pipe tee, (See New Switch Diagram). Use

thread sealant, do not over tighten.

3. Install the 1/8-NPT black pipe tee to the gas pressure switch, (See New Switch Diagram). Use thread sealant, do not over
tighten. CAUTION: Utilize the hex nut on the gas pressure switch when attaching the black pipe tee.

4. Install the supplied Brass 1/8-NPT male x ¼" compression fitting to the 1/8-NPT black pipe tee, (See New Switch Diagram ).
Use thread sealant, do not over tighten.

5. Remove the PRESSURE TAP plug from the underside of the thermostat/gas control valve and install the supplied Brass
1/8-NPT male x ¼" compression fitting, (See New Switch Diagram). Use thread sealant, do not over tighten.

IMPORTANT: DO NOT alter the heater's PILOT GAS LINE, (See New Switch Diagram).

6. Using a tube cutter, cut the appropriate length of the supplied 1/4" tubing to reach from the gas pressure switch fitting to the
PRESSURE TAP PORT fitting of the thermostat/gas control valve. Make sure each end of the tubing is not pinched closed.

7. Use the 1/4" tubing to connect gas pressure switch fitting to the PRESSURE TAP PORT fitting on the thermostat/gas control valve.

8. Conduct a gas leakage test of all connections as outlined in the latest edition of NFPA 54, ANSI Z223.1, part 4. or local codes.

NOTE: A "gauge port" can be accessed by removing the 1/8-NPT pipe plug that is on the 1/8-NPT black pipe tee (attached to

the gas pressure switch).

IMPORTANT: This gas pressure switch is an updated version with only one 1/4” aluminum
tubing connection to the pressure tap port of gas valve. The atmospheric vent connection
is no longer required, as on the Old-Style Switch. Disregard the “Gas Pressure Switch”
installation section of your VP-2/3, WHK-2, WHKE instruction manual if the old style switch
is referenced, (See Discontinued Old-Style Switch Diagram). If you are replacing an Old­Style gas pressure switch with the new style gas pressure switch follow the instructions
below. The new style switch is compatible with any previous Old-Style Switch installations.

Discontinued Old-Style Switch

DO NOT ALTER

GAS SUPPLY

INTO PRESSURE TAP PORT.

GAS PRESSURE SWITCH

GAS CONTROL VALVE

THERMOSTAT/

PILOT GAS LINE

FIGURE 700S107 2/13/04

INSTALL BRASS 1/8-NPT MALE
x 1/4" COMPRESSION FITTING

THERMOCOUPLE

BURNER GAS LINE

COMMON

MUST BE MOUNTED VERTICALLY.

GAS PRESSURE SWITCH DIAPHRAGM

IMPORTANT:

BRASS 1/8-NPT MALE x 1/4"
COMPRESSION FITTING

THERMOSTAT / GAS CONTROL

TO PRESSURE TAP FITTING OF

1/4" OUTSIDE DIAMETER

ALUMINUM TUBING - CONNECT

VALVE.

1/8-NPT BLACK PIPE TEE

1/8-NPT PIPE PLUG - NEW
PRESSURE TAP PORT

NORMALLY OPEN

MOUNTING HOLES

IMPORTANT:

New-Style Gas Pressure

Switch Installation

REV. 8 9/98

TJERNLUND PRODUCTS, INC.

1601 Ninth Street • White Bear Lake, MN 55110-6794
PHONE [phone] • [phone] • FAX [phone]
Visit our web site • www.tjernlund.com

WHK-2 WATER HEATER

CONTROL MODULE

FOR CONTROLLING A POWER VENTER OR DRAFT

INDUCER WHEN VENTING A MILLIVOLT WATER HEATER

FOR MODELS

HS115 GPAK
HSUL SS1
HST DRAFT
GPAK-T INDUCERS

OWNER INSTRUCTIONS, DO NOT DESTROY

!

Recognize this symbol as an indication of important Safety Information!

NOTE: THE WHK-2 MAY NOT BE USED ON ANY APPLIANCE

OVER 120,000 BTU/HR. ALWAYS FOLLOW WATER
HEATER MANUFACTURER’S INSTRUCTIONS FOR
PROPER OPERATION OF HEATER AND RE-LIGHTING
OF PILOT.

THESE INSTRUCTIONS ARE INTENDED AS AN AID TO QUALIFIED, LICENSED
SERVICE PERSONNEL FOR PROPER INSTALLATION, ADJUSTMENT AND
OPERATION OF THIS UNIT. READ THESE INSTRUCTIONS THOROUGHLY
BEFORE ATTEMPTING INSTALLATION OR OPERATION. FAILURE TO FOLLOW
THESE INSTRUCTIONS MAY RESULT IN IMPROPER INSTALLATION, ADJUST­MENT, SERVICE OR MAINTENANCE POSSIBLY RESULTING IN FIRE, ELECTRI ­CAL SHOCK, CARBON MONOXIDE POISONING, EXPLOSION, OR PERSONAL
INJURY OR PROPERTY DAMAGE.

DO NOT DESTROY. PLEASE READ CAREFULLY AND KEEP

IN A SAFE PLACE AT JOB SITE FOR FUTURE REFERENCE.

Copyright © 1997, Tjernlund Products, Inc. All rights reserved. P/N 8504026

TABLE OF CONTENTS

Pilot Outage.....................................................................................................................................................................1

General Cautions & Installation Restrictions ...............................................................................................................1, 2

Installation

Electrical Wiring

Operation Circuit Check ..................................................................................................................................................9

Safety Interlock Test ........................................................................................................................................................9

Combustion Air Test ........................................................................................................................................................9

Post Purge Timer Adjustment .........................................................................................................................................9

Troubleshooting......................................................................................................................................................10, 11

Warranty Claim Procedure............................................................................................................................................12

Typical Applications ......................................................................................................................................................13

Actuation & Safety Controls ..............................................................................................................................2

Solenoid Valve ..................................................................................................................................................2

Gas Pressure Switch ....................................................................................................................................2, 3

Linear Limit Spill Switch ....................................................................................................................................3

115VAC interlock with HSUL, GPAK Power Venters or Draft Inducers with 950-1040 24/115 VAC Relay ......4

115VAC interlock with HST, GPAK-T Power Venters or Draft Inducers with 950-1067 Relay/Timer ...............5

115VAC interlock with HS115 Series Power Venters or Draft Inducers............................................................6

System Schematic/WHK-2 Operation...............................................................................................................6

WHK-2/HSUL or GPAK Series Furnace or Boiler & Water Heater Connection Diagram .................................7

WHK-2/HST or GPAK-T Series Furnace or Boiler & Water Heater Connection Diagram ................................7

WHK-2/SideShot Furnace or Boiler & Water Heater Connection Diagram......................................................8

24 VAC Water Heater Connections ..................................................................................................................8

IN THE EVENT OF PILOT OUTAGE

1. Push the reset button in the center of the Linear Limit spillage sensing switch located
on the draft hood on the top of the water heater, (See Diagram A)

2. Turn the gas pilot knob at the top of water heater gas valve to “OFF” position.

Gas pilot knob MUST REMAIN IN “OFF” POSITION FOR FIVE MINUTES BEFORE
PILOT IS RE-LIT. Perform steps 3 & 4 while waiting.

3. Visually verify that there is 115 volt power established to the Power Venter.
(Check fuse or circuit breaker, wall plug and electrical connections).

4. Visually verify that all connections of the control cord circuit are intact.

5. Follow water heater manufacturer’s re-lighting instructions attached to water heater or located in water heater owner’s manual.

USER NOTE:

Since the Power Venter/Draft Inducer cannot operate during a power outage, the safety interlock controls are designed to prohibit gas
flow to the water heater. Follow the above procedures and water heater manufacturer’s instructions for relighting the pilot when power
has been restored.

OPTIONAL PILOT SAVER KIT AVAILABLE

The optional Pilot Saver Kit (P/N: 950-2061) allows for Solenoid Valve to be installed in 1/2” burner gas line from water heater gas
valve which eliminates pilot outages caused by power interruptions.

DIAGRAM A

IMPORTANT

NOTE: These instructions do NOT cover the installation of the Power Venter/Draft Inducer. Install the Power Venter/Draft

Inducer first, according to the manufacturer’s instructions before proceeding with the installation of the WHK-2. Do not con­nect 115V wiring of Power Venter/Draft Inducer. The WHK-2 is designed to interlock a millivolt appliance of up to 120,000
BTU’s with a Power Venter/Draft Inducer. The WHK-2 can be wired two different ways.

A. To interlock a single millivolt appliance, such as a water heater.
B. To interlock a millivolt appliance and provide the primary power so that one Power Venter/Draft Inducer can vent both a

water heater and a furnace/boiler.

INSTALLATION RESTRICTIONS

1. Failure to install, maintain and/or operate this device in accordance with manufacturer’s instructions may result in conditions which
can produce bodily injury and property damage.

1

2. This device must be installed by a qualified professional installer in accordance with all local codes or in their absence in

accordance with the National Electrical Code and the Occupational Safety and Health Act (OSHA) when applicable.

3. “Qualified Installer” shall mean an individual properly trained and licensed.

4. Disconnect power supply when making wiring connections or when working around the Venter motor. Failure to do so may
result in severe personal injury and equipment damage.

5. Make certain the power source is adequate for the motor requirements and all controls. Do not add a Mechanical Vent System to a
circuit where the total electrical load is unknown.

ACTUATION AND SAFETY CONTROLS INSTALLATION

After opening carton, inspect thoroughly for hidden damage. If any damage is
found notify freight carrier and your distributor immediately and file a concealed
damage claim.

1. Remove the carton labeled Actuation and Safety Controls.

2. Open this carton and remove the gas Solenoid Valve. Make sure that the
black coil guard is covering the coil of the Solenoid Valve as shown in
Diagram B.

3. Remove the 3/8” to 1/2” adapter fittings and install one adapter in each end
of the Solenoid Valve. Use a thread sealant to insure gas-tight seal. NOTE:
3/8” to 1/2” adapters are not used if using Pilot Saver kit (P/N 950-2061)

4. Install the Solenoid Valve in between the manual shut off valve and the water
heater thermostat/valve. NOTE: If installing Pilot Saver kit (P/N 950-2061),
the Solenoid Valve is installed in 1/2” burner line from water heater gas valve.

5. Verify that the arrow on the casing of the Solenoid Valve points in the direction of the water heater’s thermostat/valve. The Solenoid
Valve must be installed on the supply side of the drip tee. The Solenoid Valve should be positioned so the top of the coil cover is
on top of or horizontal to the Solenoid Valve. Do not position so that the top of the coil cover is pointing downward.

All gas piping shall be tested and inspected in accordance with NFPA 54, ANSI Z223.1, part 4. Any leakages shall be located by
means of an approved combustible gas detector, soap and water, or an equivalent nonflammable solution, as applicable. If leakage
or other defects are detected, the affected portion of the piping system shall be repaired or replaced and retested.

GAS PRESSURE SWITCH

DIAGRAM B

GAS CONTROL VALVE

Remove the gas pressure switch from the carton. Also remove the 1/8” compression
fitting, the four 1/2” x #10 self tapping screws and the 2 sections of 1/4” diameter alu ­minum tubing from the master carton liner. The gas pressure switch is mounted on
the casing of the water heater adjacent to the heater’s thermostat/valve. It should be
mounted close enough so that the supplied 1/4” tubing will reach from the gas pres­sure switch fittings to the burner. The four provided screws are self tapping and
drilling. They do not require the use of a drill. Their 1/2” length assures that the inner
tank will not be penetrated.

NOTE: Do not alter pilot gas line

1. Mount the gas pressure switch by securing it to the heater casing with a screw in each one of the four mounting holes.

2. Using a tube cutter, cut the appropriate length of 1/4” tubing to reach from the fitting marked “connect to gas valve” on Gas
Pressure Switch to the pressure tap port of the thermostat/valve, (See drawing “Gas Control Valve”). NOTE: DO NOT alter the

heater's pilot gas line.

3. Remove the pressure tap plug from the underside of the thermostat/valve and install the supplied compression fitting. Use thread
sealant, do not over tighten, (See drawing “Gas Control Valve”).

4. Connect the fitting installed in step #3 to the fitting marked “connect to gas valve” on the Gas Pressure Switch. Make sure each
end of the tubing is not pinched closed, (See Diagram C, Page 3).

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5. Measure and cut an appropriate length of tubing to reach from the fitting marked “warning” to the burner of the heater on Gas

Pressure Switch. Connect to Gas Pressure Switch and route to burner area.

NOTE: The Gas Pressure Switch has a built in pressure tap marked “gauge port” for future gas pressure testing, (See Diagram D).

DIAGRAM DDIAGRAM C

LINEAR LIMIT SPILLAGE SENSING SWITCH

PURPOSE:

To provide a means for appliance shut-down in the event of flue
blockage or Power Venter/Draft Inducer failure.

OPERATION:

When concentrated spillage of the products of combustion occurs
from the draft hood, the Linear Limit sensing switch circuit will open
preventing burner operation.

DIAGRAM E

1. Attach the Linear Limit sensing switch mounting bracket to the top
of the water heater using the sheet metal screws provided. The
Linear Limit bracket should be approximately 1/2” from the draft
hood, (See Diagram E).

2. Attach the three Linear Limit capillary mounting brackets around
the draft hood, equally spaced.

3. Insert the Linear Limit spillage sensing switch capillary into the “U”
of the Linear Limit brackets outlining the perimeter of the draft
hood. The Linear Limit capillary may be overlapped if necessary,
(See Diagram F). IMPORTANT: DO NOT CUT THE CAPILLARY, it
will be destroyed and water heater will be disabled.

4. Route the Linear Limit spillage switch cable down the water heater casing locating the end near the Solenoid Valve. Secure it with
the cable clamps and self drilling screws provided.

DIAGRAM F

TOP VIEW

3