From inside (document excerpt):
Fixed Speed Furnace Control Replacement Kit Cancels: New IIK340M-40-83 11-02 Installation Instructions Part No. 325878-751 NOTE: Read the entire instruction manual before starting the installation. SAFETY CONSIDERATIONS Installing and servicing heating equipment can be hazardous due to gas and electrical components. Only trained personnel should install or service heating equipment. Untrained personnel can perform basic maintenance functions such as cleaning coils, or cleaning and replacing filters.
All other operations should be performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels attached to the unit. Recognize safety information. This is the safety-alert symbol. When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury. Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the. DANGER identifies the safety-alert symbol, most serious hazards, which will result in severe personal injury or death. WARNING signifies a hazard, which could result in personal injury or death. CAUTION is used to identify unsafe practices which would result in minor personal injury or product and property damage. NOTE is used to highlight suggestions, which will result in enhanced installation, reliability, or operation. Follow all safety codes. Wear safety glasses and work gloves. Have a fire extinguisher available. INTRODUCTION This kit is a direct replacement for circuit boards Part No. HK42FZ004, HK42FZ007, HK42FZ008, HK42FZ009, HK42FZ011 and HK42FZ016. Changes to the operation of this control include: 1. The blower off delay selections are: 90, 120, 150 and 180 seconds. 2. A COOLING OFF DELAY DEFEAT JUMPER “J2 ” is provided. It is located in the upper left corner of control board (see Fig. 2), When cut, this permanently reduces the 90 second blower-off delay in the cooling mode, to 5 seconds. 3. All 115-volt neutrals are grouped together in one location of board (see Fig. 2) 4. Humidifier connection is removed from thermostat terminal block. It is now a ΒΌ inch spade terminal, next to the thermostat terminal block (see Fig. 2) Kit contains: Control board Wire harness adapter Non-condensing Furnace (80%) wiring diagram Condensing Furnace (90%) wiring diagram Part Number HK42FZ013 328151-701 328251-101 (rev A) 328218-101 (rev A) TWINNING The control board in this kit CANNOT be twinned with any of following circuit boards: HK42FZ004 HK42FZ007 HK42FZ008 HK42FZ009 HK42FZ011 HK42FZ016 In twinned installations another kit will be required for the twin furnace. WARNING – The ability to properly perform service on this equipment requires certain expertise, mechanical skills, tools, and equipment. If you do not possess these, do not attempt to perform any service on this equipment other than those procedures recommended in the User’s Manual. A failure to follow this warning could result in possible damage to this equipment, serious personal injury, or death. Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Catalog No. 535-80101 Printed in U.S.A Form 58MCA-17SI Pg. 1 11-02 Replaces: New ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS CAUTION – Electrostatic discharge can affect electronic components.