Description
50A55-843 Furnace Control Board Compatible with White-Rodgers Lennox
The 50A55-843 integrated furnace control is engineered as a universal replacement board for gas furnaces running a White-Rodgers 50A50 or 50A55 series control. A built-in microprocessor manages burner ignition, flame sensing and blower operation, and the board ships with the wiring harness, ROS-ROI jumper wire, mounting screws and cable ties needed to complete a standard swap in one order.
📋 Key Takeaways
- ✅ Exact Replacement: Replaces the White-Rodgers 50A55-843 control board for direct, hassle-free installation.
- ✅ Broad Series Coverage: Compatible with White-Rodgers and Lennox furnace systems, covering 50A50 series (50A50-241, 50A50-405) and 50A55 series (50A55-486) controls.
- ✅ Automatic Safety Control: Microprocessor ignition with flame confirmation, safe gas-valve shutoff on fault, and one-hour auto reset.
- ✅ Complete Installation Kit: Includes wiring harness, ROS-ROI jumper, screws and cable ties — no extra parts to buy.
- ✅ Built-in Diagnostics: On-board LED fault codes plus a field-serviceable 3 A automotive fuse that protects the low-voltage transformer.
Features & Benefits
| Feature |
Benefit (What It Means for You) |
| Microprocessor Ignition & Monitoring |
Automatic ignition with flame confirmation; continuous supervision of burner, inducer and blower. On fault the gas valve shuts down safely, and the control resets itself one hour after lockout — fewer service trips. |
| White-Rodgers & Lennox Compatibility |
Replaces the White-Rodgers 50A55-843 and covers 50A50-241, 50A50-405 and 50A55-486 series controls used in White-Rodgers and Lennox gas furnaces. |
| 25 VAC Standard Control Ratings |
Input 25 VAC 50/60 Hz at 0.45 A with gas valve relay 1.5 A and ignitor relay 6 A at 120 VAC — matched to the original system for safe operation. |
| Flame-Retardant Circuit Board |
Built on a flame-retardant PCB for dependable, long-term operation inside the furnace control compartment. |
| LED Diagnostics + 3 A Fuse |
LED flash codes point to lockout, pressure switch, limit switch and flame faults; the automotive-type fuse is the only field-serviceable part and protects the low-voltage transformer from shorts. |
| Marked Terminals + Full Kit |
Terminal markings match the original layout and wiring is included, so you can photograph the old board and move every wire to the identically marked terminal. |
Compatibility & Cross-Reference
Replaces / Interchange Part Numbers:
| Interchange Part Number |
System / Brand |
| 50A55-843 |
White-Rodgers (this replacement) |
| 50A50-241 |
White-Rodgers 50A50 series |
| 50A50-405 |
White-Rodgers 50A50 series |
| 50A55-486 |
White-Rodgers 50A55 / Lennox systems |
Common Applications:
- White-Rodgers gas furnaces using a 50A55-843 control board
- White-Rodgers 50A50 / 50A55 series gas furnaces
- Lennox gas furnace systems using 50A50 / 50A55 series controls
This control is designed for furnaces that use a silicon carbide (SiC) ignition system. Confirm the model number printed on your old board against the list above before ordering.
Specifications
| Part Number |
50A55-843 |
| Input |
25 VAC, 50/60 Hz, 0.45 A max |
| Gas Valve Relay |
1.5 A at 25 VAC |
| Ignitor Relay |
6 A at 120 VAC |
| Inducer / Circulator Relays |
Rated for furnace blower loads (2.2 FLA / 14.5 FLA) |
| Operating Temperature |
-40 to 175 °F (-40 to 80 °C) |
| Humidity |
5% - 93% RH, non-condensing |
| Fuse |
3 A automotive type (field-serviceable) |
| Board |
Flame-retardant PCB |
| Includes |
Control board, wiring harness, ROS-ROI jumper wire, mounting screws and cable ties |
Why Choose iFJF?
iFJF supplies furnace control boards factory-direct, so you get the replacement part without the dealership markup. What you can verify before you buy:
- ✅ Cross-reference you can check yourself: the replacement range (50A50-241, 50A50-405, 50A55-486) is listed openly above — match your old board number first.
- ✅ Complete kit, no hidden extras: wiring harness, ROS-ROI jumper, screws and cable ties are all in the box, so a standard replacement needs nothing else.
- ✅ Wiring guidance built for DIY: photograph and label the old wiring before removal, then move every wire to the identically marked terminal — with the ROS-ROI jumper connected, the indicator works as expected.
- ✅ Diagnostics that tell you what failed: LED fault codes and the replaceable 3 A fuse let you confirm the board state before calling for service.
Installation note: replacement should be performed by a qualified HVAC contractor or licensed electrician. Always turn off power and shut off the gas supply before removing the old control. If you are unsure whether this control matches your furnace, message us with the model number printed on your old board before ordering.
Need help finding the right part? Our support team answers fitment questions before you order — support@ifjf.com.
Looking for related upgrades? Check out our iFJF 1170063 furnace control board for ICP furnaces here →
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Frequently Asked Questions
Q: Will this replace my White-Rodgers 50A55-843 board?
A: Yes. This control is a direct replacement for the White-Rodgers 50A55-843 and operates on the same 25 VAC furnace control application, with terminals laid out to match the original board. Check the model number printed on your old board against our Cross-Reference table before ordering.
Q: Will it work in my Lennox gas furnace?
A: It is compatible with Lennox furnace systems and covers 50A50 series controls such as 50A50-241 and 50A50-405, plus 50A55 series controls such as 50A55-486. Confirm your furnace uses a silicon carbide (SiC) ignition system and verify your old board model before ordering.
Q: What is included in the package?
A: One control board, a wiring harness, a ROS-ROI jumper wire, mounting screws and cable ties. A standard replacement needs no extra parts.
Q: Why does the indicator light not come on after installation?
A: The indicator works only when the ROS and ROI terminals are connected with the included jumper wire. Connect those two terminals, then power up — the LED should flash once as a power-on self check.
Q: What if my board model is outside the listed range?
A: The White-Rodgers cross-reference chart states that the 50A55-843 universal control replaces the full 50A50 and 50A55 model families. If your board is outside the numbers listed here, message us with the exact model printed on the board before ordering so we can confirm the match.
Q: How do I protect the board during troubleshooting?
A: The 3 A automotive-type fuse is the only serviceable part and protects the low-voltage transformer from short-circuit damage. If the fuse keeps opening, find and fix the short first, then replace the fuse. Follow the maintenance schedule of your furnace manufacturer.
Package Includes
- 1 × 50A55-843 furnace control board
- 1 × wiring harness
- 1 × ROS-ROI jumper wire
- 1 × set of mounting screws and cable ties
Common Problems with Furnace Control Boards — Solved by iFJF
We analyzed verified customer reviews of OEM and aftermarket control boards in this category. Here is what owners keep complaining about — and how this board addresses it:
| ❌ What Owners Complain About |
|
✅ How This Board Addresses It |
"It says compatible but my furnace did not work"
— #1 cause of returns in this category
|
→ |
Check the model before you buy
The covered numbers (50A50-241, 50A50-405, 50A55-486) and the SiC ignition requirement are stated openly, so you can verify your old board and furnace type before ordering.
|
"Installed it and the indicator would not come on"
— Often a wiring step, not a dead board
|
→ |
ROS-ROI jumper wiring made explicit
The indicator only works when ROS and ROI are connected with the included jumper. This step is called out in the listing so it is not missed during install.
|
"No guidance, no way to check the install"
— Common DIY hesitation
|
→ |
Photo-first wiring on marked terminals
Photograph and label the old wiring before removal, then move each wire to the identically marked terminal. The full kit — harness, jumper, screws and ties — arrives in one box.
|
🔎 We read the 1-star and 2-star reviews so you don't have to. This board is engineered around the real problems owners face — not just a spec sheet.
Factory Direct Supply & Wholesale — iFJF is a direct manufacturer of high-performance replacement parts for heating and filtration systems. Custom specifications and bulk orders are highly welcome. Contact us for exclusive dealer pricing and volume discounts. Backed by ISO 9001:2015 and IATF 16949:2016 quality management system certifications.
Email: support@ifjf.com
