LED CFL Retrofit Bulbs
LED CFL retrofit lamps for 2-pin and 4-pin upgrades—choose plug-and-play or ballast-bypass strategies to control maintenance and performance.
CFL retrofit LED bulbs for fast fixture upgrades, pin-compatible replacements, and ballast strategy control
CFL retrofit LED bulbs are a practical way to modernize compact fluorescent installations without replacing the entire fixture. Designed for common commercial downlights and wall sconces, these LED replacements eliminate slow warm-up and many CFL flicker complaints while extending service life. When specified correctly, choosing plug-and-play (Type A) or ballast-bypass (Type B) retrofits can reduce energy use and simplify maintenance planning across multi-fixture buildings.
Read more about LED CFL Retrofit Bulbs
CFL retrofit performance range: 2-pin and 4-pin bases, high-CRI options, and thermal management in enclosed housings
We offer a versatile selection of 4-pin (G24q) and 2-pin (G24d) base options to match common sockets found in commercial and multifamily fixtures. Our CFL LED retrofits are engineered for consistent color performance and reliable operation, but results depend on correct socket identification, ballast strategy, and enclosure conditions—especially in tight housings where heat buildup can shorten driver life.
Answer summary: CFL retrofit LED bulbs are specified by pin configuration (2-pin vs. 4-pin), ballast strategy (Type A plug-and-play vs. Type B ballast bypass), socket compatibility, lumen output, thermal limits, and dimming behavior—not by lamp shape or wattage equivalency alone.
CFL Retrofit Compatibility, Ballast Strategy & Maintenance Context
Why Ballast Bypass Retrofits Reduce Long-Term Maintenance Labor Ballast Bypass Retrofit Considerations for Existing Fixtures Where CFL Retrofit LED Lamps Fit in Commercial Upgrades Selecting Lumens and Color Temperature for CFL Retrofit LEDs
CFL retrofit spec workflow: pin identification, ballast decision, and fit/voltage verification
Use this guide to specify CFL retrofit LEDs by socket type (2-pin vs 4-pin), ballast strategy (Type A vs Type B), and enclosure conditions. The table of contents links to the decision points that prevent no-start conditions, flicker from incompatible ballasts, and premature failures from heat buildup in enclosed fixtures.
CFL retrofit LED specification guidance
Proper CFL retrofit performance depends on correctly matching pin configuration, ballast compatibility, operating voltage, thermal constraints, and fixture enclosure conditions. Incorrect lamp selection can result in flicker, non-starting lamps, overheating, or shortened driver life.
Specification note: Common CFL retrofit failures include installing 4-pin lamps into 2-pin sockets, mixing plug-and-play LEDs with incompatible ballasts, insufficient lumen output for corridor or stairwell lighting, thermal stress in enclosed fixtures, and dimmer incompatibility that causes strobing or early driver failure.
Technical selection guide for CFL retrofit LED bulbs
CFL retrofits succeed when you confirm the socket first, then choose the ballast approach that matches your maintenance strategy and electrical constraints. Use the sections below to align base type, ballast plan, lumen output, and control behavior before standardizing across a property.
Pin configuration and base identification
The first step is identifying the existing socket. 2-pin (G24d) and 4-pin (G24q) bases are not interchangeable, and the fixture’s ballast type often correlates with the pin configuration. Correct identification prevents mechanical mismatch and avoids non-start conditions.
Selection rule: Match the LED retrofit to the exact pin configuration and socket family in the fixture before evaluating output, CCT, or dimming.
Pin configuration & base identification: match the socket before selecting a retrofit
| Base family | Pin count | Common socket label | Typical legacy setup | Retrofit selection rule |
|---|---|---|---|---|
| G24d | 2-pin | “2-pin” / “G24d” | Often non-dimming CFL ballasts; common in downlights and sconces | Match the exact 2-pin base; do not substitute 4-pin lamps |
| G24q | 4-pin | “4-pin” / “G24q” | Often used with dimming-capable CFL ballast systems (varies by model) | Match the exact 4-pin base and verify ballast strategy (Type A or Type B) |
Type A vs. Type B retrofit strategy
Type A (plug-and-play) lamps operate on the existing ballast for faster installation, while Type B (ballast bypass) lamps remove the ballast from the circuit and run on line voltage—eliminating a common future failure point. Your choice affects install labor, future service calls, and standardization across a building.
Selection rule: Choose Type A when speed and minimal rewiring are the priority and compatible ballasts are confirmed; choose Type B when you want to remove ballast failures and standardize on direct-wire reliability.
Type A vs. Type B retrofit strategy: install speed vs long-term reliability
| Decision factor | Type A (plug-and-play) | Type B (ballast bypass) | Best practice |
|---|---|---|---|
| Installation labor | Fastest (no rewiring) | Higher (rewire/bypass ballast) | Choose Type A for speed when compatibility is proven |
| Future maintenance | Ballast remains a future failure point | Ballast eliminated (fewer service calls) | Type B is preferred for long-term standardization |
| Performance predictability | Depends on ballast model/condition | Most predictable (line-voltage operation) | If ballast models vary across a property, lean Type B |
| No-start / flicker risk | Higher if ballast is incompatible or aging | Lower if wiring is correct | Type A requires a verified ballast compatibility list |
Ballast compatibility and no-start prevention
Plug-and-play retrofits require ballast compatibility. Incompatible ballasts can cause flicker, intermittent starting, audible noise, reduced lamp life, or complete no-start behavior—especially as ballasts age or vary by manufacturer across a property.
Selection rule: If you’re using Type A, verify ballast compatibility and avoid mixing ballast models on the same lamp spec; if compatibility cannot be confirmed, move to Type B for predictable performance.
Type A ballast compatibility: risk flags and prevention steps
| Symptom / risk | Likely cause | Best fix | Prevention rule |
|---|---|---|---|
| No-start | Incompatible ballast model, aged ballast, incorrect lamp family | Verify ballast model; switch to listed-compatible lamp or convert to Type B | Do not standardize Type A without compatibility verification |
| Flicker / shimmer | Ballast output instability, dimming path mismatch | Use a ballast-approved lamp; if inconsistent across areas, go Type B | Avoid mixing ballast models under one lamp spec |
| Audible noise | Ballast resonance or aging components | Replace ballast or convert to Type B | Noise complaints usually increase as ballasts age |
| Intermittent operation | Thermal stress, ballast nearing end of life | Convert to Type B; confirm enclosure heat conditions | High-duty-cycle areas benefit most from Type B |
Lumen output planning for common areas
Corridors, stairwells, and lobbies typically require consistent ambient light and good vertical illumination for faces, doors, and signage. Under-lamping creates dim runs; over-lamping can create glare in downlights and wall sconces.
Selection rule: Set lumen output based on ceiling height and spacing, then standardize across zones to maintain uniform appearance and simplify maintenance inventories.
Lumen planning for common areas: avoid dim runs and glare in downlights
| Area type | Coverage goal | Output guidance | Common mistake |
|---|---|---|---|
| Corridors | Uniform ambient with good vertical visibility | Standardize lumen package by ceiling height & spacing | Mixed outputs creating “bright/dim” patches |
| Stairwells | Safe step visibility and face recognition | Avoid under-lamping; prioritize consistent distribution | Too-low output causing shadowed landings |
| Lobbies / entries | Comfortable brightness without glare | Use higher output only if glare is controlled in the optic/trim | Over-lamping downlights that create hot spots |
Thermal limits in enclosed fixtures
Many CFL fixtures are enclosed or semi-enclosed, which can trap heat and shorten LED driver life if the lamp isn’t designed for those conditions. Downlights, sealed globes, and tight wall sconces can run hotter than expected in 24/7 or high-duty-cycle applications.
Selection rule: Confirm enclosure suitability and avoid pushing maximum lumen output in tight housings unless the retrofit is designed for elevated thermal conditions.
Thermal & enclosure suitability: preventing premature failures in tight CFL fixtures
| Fixture condition | Heat risk | Spec recommendation | If ignored |
|---|---|---|---|
| Sealed globe / enclosed sconce | High | Use retrofits designed for elevated thermal conditions; avoid max output | Early driver failure, color shift, intermittent operation |
| Downlight can with restricted airflow | Medium–High | Confirm suitability for recessed housings; keep output aligned to heat limits | Shortened life, thermal dropout |
| High duty-cycle zones (10+ hrs/day or 24/7) | High | Prioritize thermal headroom; standardize one proven lamp family | Frequent replacements and inconsistent appearance |
Dimming behavior and flicker control
CFL retrofit dimming behavior depends on the control path (ballast, driver, and dimmer type). Some retrofits are not intended for dimming, and incompatible dimmers can cause strobing, limited range, or early driver stress.
Selection rule: Specify dimming only when the full control chain is known and compatible, and validate low-end performance before deploying at scale.
Dimming validation: confirm the control chain before deploying at scale
| Scenario | Risk | Best approach | Success criteria |
|---|---|---|---|
| Type A + unknown ballast | High (flicker/no-start) | Avoid dimming claims unless ballast compatibility is verified | Stable operation across the full zone |
| Type A + verified ballast list | Medium | Use only approved ballasts and standardize models | No shimmer at low dim; no audible noise |
| Type B (bypass) + known dimmer | Lower | Validate dimmer/driver compatibility and minimum dim level | Predictable low-end without dropout |
Commercial Project Support
Need documentation, lead-time visibility, or closeout-ready deliverables? Use the resources below to route your project correctly and reduce revision cycles.
- Commercial Project Support (Hub)
- Quote Intake & Project Routing
- Photometrics
- Submittals
- Shipping Reliability & Fulfillment
- Closeout Documentation
- Returns & Restocking
- Warranty Claims
- Frequently Asked Questions
FAQs
How do I know if my CFL retrofit is 2-pin or 4-pin?
Check the socket: 2-pin lamps use G24d bases and 4-pin lamps use G24q bases. They are not interchangeable, so identify the pin configuration before selecting a retrofit.
What is the difference between Type A and Type B CFL retrofit LEDs?
Type A (plug-and-play) uses the existing ballast for faster installation, while Type B (ballast bypass) removes the ballast and powers the lamp from line voltage—eliminating future ballast failures.
Why do some plug-and-play CFL LEDs flicker or fail to start?
Flicker or no-start behavior is commonly caused by incompatible or aging ballasts. If ballast compatibility can’t be verified across the building, a Type B bypass approach is often more predictable.
Can I use CFL retrofit LEDs in enclosed fixtures?
Many CFL fixtures are enclosed or run hot. Confirm the retrofit lamp is suitable for restricted airflow and avoid over-lamping output in tight housings to reduce thermal stress and premature driver failure.
Are CFL retrofit LEDs dimmable?
Some are, but dimming depends on the ballast/driver and dimmer path. Only specify dimming when compatibility is confirmed, and validate low-end performance to avoid strobing or limited dim range.
Expert reviewed for commercial specification
Brandon Waldrop
Lead Commercial Lighting Specialist • Documentation + Layout Support
The LED CFL Retrofit Bulbs collection is reviewed for socket-true pin compatibility, ballast-strategy control, and enclosure-safe thermal performance so compact downlights, wall sconces, and common-area fixtures can be upgraded without no-start surprises, flicker complaints, or premature driver failures.
Collection review focus:
Verified for pin-family accuracy (2-pin G24d vs 4-pin G24q) and common socket labeling discipline so retrofits are mechanically compatible and start reliably without “wrong base” service calls; verified for ballast-strategy clarity (Type A plug-and-play vs Type B ballast bypass) so the spec matches install labor reality and long-term maintenance posture instead of drifting fixture-by-fixture; verified for Type A ballast-compatibility risk control (ballast model variance, aging behavior, and property-wide inconsistency) so standardization doesn’t trigger flicker, intermittent starts, audible noise, or no-start zones; verified for Type B line-voltage fit and bypass execution discipline so direct-wire conversions deliver predictable operation without troubleshooting churn; verified for lumen right-sizing for common-area runs (corridors, stairwells, lobbies, and multi-fixture spacing) so you avoid dim patches, hot spots, and glare-driven complaints after occupancy; verified for thermal headroom in enclosed and restricted-airflow housings (sealed globes, tight sconces, recessed downlights, and high duty-cycle locations) so output choices stay within heat reality and driver life isn’t sacrificed for “more lumens”; verified for dimming realism by control chain (ballast/driver path, dimmer type, low-end stability, and zone consistency) so “dimmable” claims translate into stable performance without strobing, dropout, or uneven curves; verified for color policy continuity (CCT discipline and appearance consistency across phased replacements) so upgraded areas don’t read patchy or mismatched as buildings are converted over time; verified for documentation posture at the SKU level (compatibility notes, installation constraints, and setting records where applicable) so installs match approvals and future swaps don’t change performance or appearance unexpectedly.
Team-backed support: Quotes, photometrics, submittals, shipping visibility, and closeout documentation are supported through Commercial Project Support . Call 800-357-6860.
LED CFL Retrofit and PL Lamp Engineering Resources
