LED DownlightsRecessed
WAC R4*D**-*840-**** (15W) LED Downlight Manual
Setup, everyday use, maintenance and troubleshooting for the 4 in. recessed LED downlight, with verified specifications.
- Light output1,550 lumens
- Power15 W
- Efficacy103 lm/W
- Color temp.4000K
About the WAC R4*D**-*840-**** (15W)
The WAC R4*D**-*840-**** (15W) is a 4 in. recessed LED downlight certified under the ENERGY STAR program for light fixtures. It produces 1,550 lumens from 15 W of input power, an efficacy of 103 lumens per watt. That efficacy is better than 91% of the 3,089 Recessed models in our database.
Light quality: the fixture offers a 4000K color temperature (neutral white) and a color rendering index of 83.
Notable features include continuous dimming, an IC rating for direct contact with ceiling insulation, and an airtight housing rating. The rated light-source life is 55,000 hours.
Specifications
| Brand | WAC |
|---|---|
| Model number | R4*D**-*840-**** (15W) |
| Fixture type | Recessed |
| Nominal size / aperture | 4 in. |
| Light output | 1,550 lumens |
| Input power | 15.0 W |
| Efficacy | 103.3 lm/W |
| Color temperature(s) | 4000K |
| Color rendering index (CRI) | 83 |
| Rated light-source life | 55,000 hours |
| Power factor | 0.98 |
| Continuously dimmable | Yes |
| Indoor / outdoor use | Indoor |
| Insulation contact rating | IC |
| Airtight rated | Yes |
| Tunable / selectable white | No |
| Full-color tunable | No |
| Selectable light output | No |
| Occupancy sensor | No |
| Connected (smart) capable | No |
Safety information
- Turn off power at the circuit breaker — not just the wall switch — before installing, removing or servicing the fixture, and confirm the circuit is dead with a non-contact voltage tester.
- Installation must comply with the National Electrical Code (NEC) or Canadian Electrical Code (CEC) and local codes. Many jurisdictions require a licensed electrician and a permit for new fixture locations or new wiring; if you are not comfortable with household wiring, hire one.
- Use only the junction box, housing, or mounting hardware specified in the installation instructions, and do not exceed the box-fill limits of the junction box.
- Install the fixture only on a circuit whose voltage matches the label, and never modify the LED driver or module.
- Connect dimmable fixtures only to dimmers the manufacturer lists as compatible, and keep the total connected LED load within the dimmer's LED rating (often much lower than its incandescent rating).
Installation and first-time setup
Recessed downlights mount above the ceiling, either in a new-construction housing fixed to joists before the drywall goes up or in a remodel housing that clips into a cutout in an existing ceiling. This model is a 4 in. fixture; use the cutout template from the manufacturer — never estimate the hole size.
- Plan the layout
Check for joists, ducts and pipes before cutting. As a starting point for general lighting, space fixtures about as far apart as the ceiling is high, and keep them about half that distance from walls; use closer spacing or more lumens for task areas.
- Turn off power
Switch off the breaker feeding the circuit and verify it is dead.
- Cut the opening
Trace the template and cut the opening with a drywall saw or hole saw. Keep the cut clean so the trim covers it fully.
- Wire the junction box
Feed the supply cable into the fixture's junction box through a cable clamp. Connect line to line, neutral to neutral and ground to ground with listed connectors, and close the box cover.
- Set options
Check any selectors on the driver before the fixture goes into the ceiling.
- Install the fixture
Push the housing or canless module into the opening until the mounting clips or springs grip the drywall and the trim sits flush.
- Restore power and test
Turn on the breaker and check operation through the full dimming range.
Using your downlight
Dimming
The fixture dims continuously. Check the manufacturer's compatibility list: most LED drivers work best with trailing-edge (ELV) or LED-rated dimmers, and some dimmers have a low-end trim adjustment that stops flicker at the bottom of the range.
Light output and placement
At 1,550 lumens, this is a bright fixture for kitchens, work areas, commercial spaces and ceilings up to about 10–12 ft. LED fixtures reach full brightness instantly and are not shortened by frequent switching.
Care and maintenance
| When | What to do |
|---|---|
| Every 3–6 months | Dust the trim and lens with a soft, dry microfiber cloth with the light off and cool. Do not spray cleaner directly onto the fixture. |
| Every year | Check that the trim still sits flush and the springs or clips hold it firmly. A sagging trim can leave a gap that lets attic air leak. |
| When cleaning greasy kitchens | Wipe the lens with a cloth dampened in mild soapy water, then dry it. Avoid solvents and abrasive pads, which can cloud the lens. |
The integrated LEDs are not user-replaceable bulbs. The rated light-source life of 55,000 hours works out to roughly 50 years at 3 hours a day, or about 13 years at 12 hours a day. Over time the LEDs gradually dim rather than burning out; when output becomes too low, or if the driver fails, replace the fixture or LED module as the manufacturer directs.
Troubleshooting
Most downlight problems trace back to dimmer compatibility or wiring connections. Always turn off the breaker before opening the fixture or the junction box.
| Problem | Possible cause | What to try |
|---|---|---|
| Light does not turn on | Breaker off or tripped; loose wire connection; switch or dimmer failure. | Check the breaker; with power off, confirm connections in the junction box are tight; test with a standard switch. |
| Flickers or buzzes when dimmed | Dimmer not compatible with the LED driver; dimmer low-end trim set too low; too many or too few fixtures on the dimmer. | Use a dimmer on the manufacturer's compatibility list; adjust the dimmer's low-end trim; keep the load within the dimmer's LED rating. |
| Faint glow when switched off | Illuminated or smart switch leaking a small current; shared neutral wiring issue. | Try a standard switch; use a smart switch that has a neutral connection; have an electrician check the wiring. |
| Does not dim smoothly or turns off at low settings | Dimmer range not matched to the driver. | Raise the dimmer's minimum setting; consult the dimmer and fixture compatibility notes. |
| Color looks different from the other fixtures | Fixture has a different color temperature from neighboring fixtures. | Use fixtures with the same color temperature (this model is 4000K). |
| Trim falls or hangs below the ceiling | Springs or clips not engaged; opening cut too large. | Reseat the springs in the receivers; use a trim with a wider flange or repair the drywall. |
| Turns off by itself after running a while | Driver overheating, often from insulation packed around a fixture or a loose connection. | Turn off power and check the installation. Do not cover Non-IC fixtures with insulation; call an electrician if the problem continues. |
Energy use and running costs
The WAC R4*D**-*840-**** (15W) draws 15 W. Used 3 hours a day — a typical home assumption — it consumes about 16.4 kWh a year, roughly $2.79 per year at an electricity price of $0.17 per kWh. In a commercial space lit 12 hours a day, the same fixture uses about 66 kWh, or $11.17 a year.
Efficacy — lumens of light per watt of electricity — is the best single measure of a fixture's efficiency. This model delivers 103 lm/W. That figure is better than 91% of the 3,089 Recessed models in our database.
| Daily use | Energy per year | Cost per year |
|---|---|---|
| 1 hour | 5.5 kWh | $0.93 |
| 3 hours | 16.4 kWh | $2.79 |
| 6 hours | 32.9 kWh | $5.58 |
| 12 hours | 65.7 kWh | $11.17 |
The listed power factor is 0.98, high enough that the fixture draws current efficiently from the supply — useful in commercial buildings with many fixtures on one circuit.
Dimming reduces power roughly in proportion to light output.
Frequently asked questions
How bright is the WAC R4*D**-*840-**** (15W)?
It is rated at 1,550 lumens while drawing 15 W, for an efficacy of 103 lumens per watt.
Is the WAC R4*D**-*840-**** (15W) dimmable?
Yes. It is continuously dimmable. Use a dimmer the manufacturer lists as compatible for flicker-free operation.
What color temperature is the WAC R4*D**-*840-**** (15W)?
It is a 4000K fixture with a CRI of 83.
What size is the WAC R4*D**-*840-**** (15W)?
Its nominal size is 4 in. Confirm the exact cutout or housing dimensions in the manufacturer's installation sheet before purchasing.
Can the WAC R4*D**-*840-**** (15W) touch insulation?
Yes. It is IC rated, which allows direct contact with thermal insulation, and it is also airtight rated to limit air leakage.
How much does it cost to run the WAC R4*D**-*840-**** (15W)?
At 3 hours a day and $0.17/kWh, it costs about $2.79 a year to operate.
Sources and disclaimer
Specifications on this page come from the ENERGY STAR certified led downlights dataset published by the U.S. Environmental Protection Agency (record certified March 31, 2025), retrieved October 7, 2026.
The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with WAC. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact WAC or an authorized service provider for warranty repairs and replacement parts.
Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.
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