Introduction of New Control Board for 2-Stage Gas Furnaces

Three new two-stage control boards were introduced in September (Date Code F3607) to the products listed below. The change allows the addition of new features and enhanced dependability.

Part Number	Series	Gas Code	Models	Processor	Single Stg	LEDs	New Flash	Fuse
62-102635-01	80 Plus, 2 Stg, PSC	GW	RGLQ, RGPQ	New	JUMPER	3	Yes	Yes
62-102636-01	90 Plus, 2 Stg, PSC	GU	RGTK	New	JUMPER	3	Yes	Yes
62-102636-01	90 Plus, 2 Stg, PSC	GV	RGRL, RGRK	New	JUMPER	3	Yes	Yes
62-102637-01	80 Plus, 2 Stg, ECM	GX	RGLR, RGPR	New	JUMPER	4	Yes	Yes

PLEASE NOTE THE FOLLOWING SINGLE-STAGE vs. TWO-STAGE THERMOSTAT OPERATION:

Single-Stage Thermostat Operation: Furnaces can be used on Single Stage Thermostats. Connect (W) on the Thermostat to (W) on the control board, not (W2). The jumper (P7) found on the new control boards, MUST BE MOVED from the Factory Setting of "none" to either, "5" (minutes) of low fire, or "12" (minutes) of low fire, (low fire is 70% of rated input). The (P7) jumper is located near the Neutral and Accessory terminals on the adjoining edge of the control board.

NOTE: Failure to move Jumper (P7), from "none" will result in the furnace operating at only the low firing rate and never reaching the high firing rate (at 100% heat). This is a change from the previous Single Stage operation, in that connecting W2, of the furnace, to the single stage "W" terminal of the thermostat, provided low fire for 12 minutes then high fire. This information was not included in the initial Installation Instructions, but is being corrected.

Two-Stage Thermostat Operation: Wire the thermostat W1 and W2 to the control board (W) and (W2. Leave the (P7) jumper in the FACTORY SETTING, the "none" position. The furnace is now ready for two-stage operation.

NOTE: If the (P7) jumper is moved to the staging feature (either the (5) minute or (12) minute settings), when using a two-stage thermostat and the thermostat W1 and W2 are connected to the control board (W) and (W2), the furnace will operate with those parameters (switch to high fire after 5 or 12 minutes of low fire), if no second stage call (W2) is present.

Common Features

Control boards are now grounded, by the control harness plug connector that attaches to the control board at pin position #9 (previously the board was grounded directly to the mounting plate assembly).
All have Power (Green), Status (Green) and Flame Sense (Amber) LEDs. A new flash code (6 flashes on the Green Status LED) was added. The "6" flash code indicates reversed polarity (line and neutral power leads), or no ground.
Jumpers for blower off-delay (P6) and Single-Stage Thermostat selections (P7).
All have on-board 3-amp fuse, eliminating the need for fused transformers.

Individual Board Differences

90 Plus fires on high speed inducer/high fire, drops to low when a call for low fire is present. 80 Plus fires on low and rises to high fire on a call for second stage. For this reason the boards are not interchangeable (P1 wiring harness connectors are also different and different colors, to prevent mixing the applications.)
Boards are backward compatible (including GX, ECM for a single board replacement of primary and daughter board) but each of the three boards requires a PROSTOCK kit, 62-102635-81, 62-102636-81 and 62-102637-81 which includes harness, ground wire and instructions for replacing previously used control boards. In the future, PROSTOCK will provide links as inventories of old controls are used.
Fuel code (GX) ECM control board (62-102637-01) has a "red" LED. This LED allows the contractor to determine blower motor CFM. (1 flash=100CFM.)
Fuel code (GX) ECM control board is a single board. No daughter board is used.
80 Plus with ECM (62-102637-01) has additional plug and mini-switches and no (P8) jumper for Twin operation. (ECM models cannot be twinned.)
Fuel codes GU, GV and GW with PSC motors can be twinned, but cannot be used with two-stage condensers. (PSC motors can only provide one cooling speed, ECM models are programmed for Y and Y2 indoor blower operation with two speeds based on two-stage outdoor condenser operation).