Need Custom Pricing? Request a Quote!
Request a free quote for bulk orders or repairs—response in 24 hours. Or get tailored advice and a quote for your automation needs.
Get Your Free Quote!
Honeywell's 7800 SERIES product line spans decades of flame safeguard controllers, from the original relay-based RM series to the current microprocessor-based EC series. When you need to replace an aging controller, the first question is always: which new part number replaces my old one?
This cross-reference guide maps every RM-series controller we carry to its EC-series equivalent (where available), lists compatible flame amplifiers, and explains the part number coding system so you can decode any Honeywell burner control order number on sight.
RM to EC Series Cross-Reference Table
The EC7800 series is Honeywell's microprocessor-based replacement platform for the legacy RM series. EC modules mount on the same Q7800 wiring subbase, use the same flame amplifiers, and maintain the same terminal assignments — making the upgrade a module-level swap.
| Legacy RM Series | Function | EC Series Replacement | Key Upgrade Benefit |
|---|---|---|---|
| RM7800 (E, L, G, M variants) | LF&HF flame safeguard programmer | No direct single EC equivalent — see RM7895 path below | — |
| RM7840 (L variants) | Programmable LF&HF programmer | No direct single EC equivalent — see RM7895 path below | — |
| RM7850 | Intermittent pilot control | EC7850A1080 | Digital self-diagnostics, S7800 keyboard support |
| RM7890 | On/off primary control | EC7890B1028 | Digital self-diagnostics, S7800 keyboard support |
| RM7895 | Microprocessor timing, relay outputs | Continues as current platform (bridge between RM and EC) | Already microprocessor-based |
Note: For RM7800 and RM7840 controllers, the upgrade path is typically RM7800/RM7840 → RM7895 (microprocessor timing with relay outputs) rather than a direct jump to the EC platform. The RM7895 provides the digital timing control of the EC series while maintaining relay-based output compatibility. See our RM7800 to EC7800 Upgrade Guide for the full migration decision framework.
Complete Part Number Inventory
RM7800 Series — LF&HF Flame Safeguard Programmers
| Part Number | Voltage | Purge Type | Status |
|---|---|---|---|
| RM7800E1010 | 120 VAC | Measured purge | In stock |
| RM7800L1012 | 120 VAC | Standard purge | In stock |
| RM7800L1079 | 120 VAC | Standard purge | In stock |
| RM7800L1087 | 120 VAC | Standard purge | In stock |
RM7840 Series — Programmable Flame Safeguard
| Part Number | Voltage | Key Feature | Status |
|---|---|---|---|
| RM7840L1018 | 120 VAC | Adjustable purge & pilot timing | In stock |
| RM7840L1075 | 120 VAC | Extended purge capability | In stock |
RM7850, RM7890, RM7895, RM7897, RM7898 Series
| Part Number | Series | Function | EC Equivalent |
|---|---|---|---|
| RM7850A1019 | RM7850 | Intermittent pilot, interrupted ignition | EC7850A1080 |
| RM7890A1015 | RM7890 | On/off primary control | EC7890B1028 |
| RM7890A1031 | RM7890 | On/off primary control | EC7890B1028 |
| RM7895A1014 | RM7895 | Microprocessor programmer | Current platform |
| RM7895B1013 | RM7895 | Microprocessor programmer, enhanced diagnostics | Current platform |
| RM7897A1002 | RM7897 | Automatic programming control | Contact us for upgrade path |
| RM7898A1000 | RM7898 | Full-featured burner management | Contact us for upgrade path |
EC7800 Series — Microprocessor Platform
| Part Number | Function | Replaces |
|---|---|---|
| EC7850A1080 | Microprocessor intermittent pilot control | RM7850 series |
| EC7890B1028 | Microprocessor on/off primary control | RM7890 series |
How to Read a Honeywell Burner Control Part Number
Every Honeywell 7800 SERIES part number follows the same structure. Once you know the pattern, you can identify any controller's function, generation, and configuration just by reading the part number.
Controller Module Format: RM/EC + Series + Variant Letter + 4-Digit Code
| Position | Example: RM7800L1012 | Meaning |
|---|---|---|
| RM or EC | RM | Generation — RM = relay module, EC = electronic control (microprocessor) |
| 7800 | 7800 | Series family — 7800 = LF&HF programmer, 7840 = programmable, 7850 = intermittent pilot, 7890 = on/off, 7895 = microprocessor timing |
| L | L | Variant letter — indicates voltage, configuration, and feature set (E, G, L, M are common for RM7800) |
| 1012 | 1012 | Specific model code — defines exact timing, output, and feature combination |
Flame Amplifier Format: R + Series + Variant Letter + 4-Digit Code
| Position | Example: R7847A1074 | Meaning |
|---|---|---|
| R | R | Flame amplifier module |
| 7847 | 7847 | Detection type — 7847 = rectification (flame rod), 7849 = ultraviolet, 7861 = infrared/flame signal |
| A | A | Variant — A = standard, B = dynamic/enhanced |
| 1074 | 1074 | Specific model code |
Flame Amplifier Cross-Reference
Flame amplifiers are interchangeable across all 7800 SERIES controllers (RM and EC), as long as the detection type matches your installed sensor.
| Part Number | Detection Type | Sensor Used | Best For |
|---|---|---|---|
| R7847A1033 | Rectification | Flame rod | Gas burners |
| R7847A1074 | Rectification | Flame rod | Gas burners |
| R7847B1072 | Rectification (dynamic self-check) | Flame rod | Gas burners requiring self-check |
| R7849A1023 | Ultraviolet | UV scanner (C7027, C7035) | Oil, gas, or combination burners |
| R7849B1021 | Ultraviolet Ampli-Check | UV scanner | Applications requiring amplifier self-check |
| R7861A1026 | Infrared / flame signal | IR detector | Applications where UV is not suitable |
| R7861A1034 | Infrared / flame signal | IR detector | Applications where UV is not suitable |
Accessories Cross-Reference
| Part Number | Description | Compatible With |
|---|---|---|
| S7800A1142 | Keyboard Display Module — status display, parameter configuration, fault history | EC7800 series, RM7895 |
| ST7800A1047 | Purge Timer — 40-second purge timing card | All 7800 SERIES controllers |
Frequently Asked Questions
Can I replace an RM7890 with an EC7890 without changing the wiring?
Yes. The EC7890B1028 is a direct module-level replacement for the RM7890 series. Both use the same Q7800 wiring subbase and the same terminal assignments. Remove the RM7890 module, insert the EC7890, and the wiring stays as-is. The EC7890 adds digital diagnostics and S7800 keyboard display capability as bonuses.
What does the letter after the series number mean (e.g., the "L" in RM7800L)?
The variant letter indicates the voltage and configuration group. "L" typically denotes 120 VAC standard configuration, while "E" indicates a measured purge variant and "G" often denotes a specific output arrangement. The exact meaning varies by series, so always cross-reference the full part number with Honeywell's product data sheet for your specific model.
Is there a direct EC replacement for the RM7800?
There is no single EC-series part number that directly replaces the RM7800. The recommended upgrade path for RM7800 users is to move to the RM7895 (microprocessor timing with relay outputs) for a direct functional upgrade, or to the full EC7800 platform for maximum diagnostic capability. Both options mount on the same Q7800 subbase. Contact us for help selecting the right replacement for your specific RM7800 variant.
Are R7847 and R7849 flame amplifiers interchangeable?
No. The R7847 is a rectification amplifier designed for flame rod sensors, while the R7849 is an ultraviolet amplifier designed for UV scanner sensors. They detect flame using completely different principles and are not interchangeable. Using the wrong amplifier type will result in no flame signal and immediate lockout. Always match the amplifier to your installed sensor type.
Back to main guide: Honeywell Burner Control Replacement Guide: RM7800 vs RM7840 vs EC7800 Series