Models covered: SL18 WallPlug | SL36 WallPlug | SL18-HVAC | SL36-HVAC
20 min Install Time 8,000 Hours Lamp Life 253.7 nm UV-C WavelengthBefore You Begin: HVAC models must be installed by a licensed HVAC technician or electrical contractor. Installation by anyone other than a qualified professional voids the warranty. All installations must comply with applicable national and local building codes. Read all safety warnings in full before handling any components.
Suitable for Air-Handling Use Dry Locations Only ETL Listed (Certification Pending)
Find a certified installer in our professional directory.
Contact UsRead every safety section below before touching any component. These warnings apply to all models and all installation environments.
This luminaire is designed for use with germicidal lamps and must be installed per the provided instructions to prevent exposure of eyes and bare skin to harmful UV radiation.
Always turn off the main power switch before plugging in or performing any maintenance on the unit.
Contact with live electrical components can cause serious injury or death.
Handle the UV lamp with gloves at all times. Oils from bare hands reduce UV output and cannot be reversed by cleaning.
If the lamp glass is touched without gloves, wipe the affected area with isopropyl alcohol before powering the unit on.
Never touch a broken UV lamp with bare hands.
UV lamps contain a small amount of mercury and may be harmful to skin and eyes if released. If mercury contacts skin, wash the area immediately with mild soap and water and seek medical attention if necessary. Carefully collect broken pieces and dispose of them in accordance with local environmental regulations.
UV-C light travels in a straight line and will degrade certain materials that fall within its direct path over time. Plastic drain pans, flex duct liner, foam insulation, filter media, and exposed wiring are all susceptible.
Before installing, shield any vulnerable materials with aluminum foil tape. Metal ductwork and components are unaffected.
Improper installation, adjustment, alteration, service, or maintenance can result in fire or electrical shock.
This unit is rated for dry locations only and must be installed exclusively in supply or return ductwork. It is not intended for supplemental heating applications and must not be installed in ductwork where supply air temperature regularly exceeds 105°C (221°F).
Ce luminaire est conçu pour être utilisé avec des lampes germicides et doit être installé conformément aux instructions afin d'éviter toute exposition des yeux ou de la peau aux rayons UV nocifs.
A Germicidal UV-C bulb
B Steel mounting bracket with lamp holder
C Wall adapter (WallPlug) or external ballast (HVAC)
D 4-pin keyed connector cable
E Threaded strain relief for duct wall (1" hole)
F Creates 1" cable hole (all models) & ½" sight glass hole (HVAC)
G ETL compliance sticker & drill guide
H Pressed into ½" hole to view lamp
I Non-magnetic surface mount & ballast mounting
Disclaimer: The information in this guide is provided for educational purposes only. BioShieldUV is a manufacturer of UV-C air treatment devices and does not provide installation services. All installations must be performed in compliance with applicable national and local electrical and mechanical codes. BioShieldUV makes no pesticidal claims. UV-C technology does not replace filtration, ventilation, or other air quality measures. Results will vary based on system configuration, installation location, and proper maintenance. UV lamps contain small amounts of mercury. Dispose in accordance with local environmental regulations. For recycling information, visit www.lamprecycle.org.If the mounting surface is non-ferrous or the magnetic hold is not sufficient, snap the mounting bracket apart by bending it at the joint, remove the magnet, and attach the bracket directly to the duct wall using the included self-tapping screws [I]. Seal any insulation that was disturbed with aluminum foil tape to prevent air leakage.
| System Type | Recommended Placement |
|---|---|
| Upflow (furnace below, coil above) | Return side of the air handler for direct coil cavity access |
| Downflow (furnace above, coil below) | Supply side of the air handler |
| Horizontal system | Either side of the air handler with unobstructed line-of-sight to the coil face |
| Heat pump (no furnace) | Inside the air handler cabinet, aimed directly at the coil |
The lamp assembly must fit completely inside the duct cabinet. Make sure there is 18 to 23 inches of open space in the direction the lamp will extend.
The magnetic bracket [B] will only stick to steel. Test the surface with a household magnet before choosing the location. If the magnet does not stick, use the screw-mount method described in Step 4.
Position the lamp to cover the drain pan in addition to the coil face as the drain pan is one of the most common sites for mold accumulation. Avoid pointing the lamp directly at filter media, as UV-C degrades filter materials with sustained exposure. Do not install downstream of a humidifier.
Disclaimer: Aim the lamp at the center gap between the two angled coil panels inside the unit. This middle pocket is where mold and buildup most commonly collect. 02
With gloves on, pass the lamp base [A] through the opening in the magnetic mounting bracket [B] and fasten it using the included quick nuts. The lamp should seat firmly against the bracket with no visible gaps.
03
Connect the lamp cable [D] to the 4-pin connector on the UV lamp [A]. Align the keyed tabs on the connector with the corresponding slots on the lamp, then press firmly until you feel a definitive click.
Do not force the connection. If you encounter resistance, pull back, recheck alignment, and try again. 04
Hold the magnetic base [B] against the chosen steel surface inside the air handler and allow it to snap into position. Confirm the lamp is angled correctly toward the coil before routing the cable. The magnet allows you to reposition the bracket freely at this stage, so take the time to confirm placement before moving on.
After wiring is complete, see How to Confirm the Lamp is Working →Confirm your model before proceeding as wiring differs between WallPlug and HVAC models.
01
Using the included step drill bit [F], drill a 1" hole through the air handler cabinet wall.
Insert the cable gland [E] into the hole from the outside of the cabinet.
Thread the locknut from the inside and tighten until secure.
03
Feed the appropriate cable through the gland into the cabinet:
Leave enough slack inside for a relaxed connection.
Tighten the gland nut finger-tight to secure the cable and seal the opening.
WallPlug models use the built-in LED on the power adapter to confirm lamp status where blue means operating, red means service is needed.
The warning sticker and sight glass lens give HVAC installers and homeowners a way to confirm lamp operation from the exterior of the duct without opening the cabinet. Install both components before closing up the system.
01
Select a location on the exterior duct wall that corresponds to the area directly behind or beside the installed lamp. Clean and dry the surface, then press the warning sticker [G] firmly into place. The printed circle at the centre of the sticker serves as the drill guide for the next step.
Do not remove or cover this sticker. It satisfies ETL safety marking requirements and must remain visible for the life of the installation. 02
Using the included step drill bit [F], drill a 1/2" hole through the centre of the printed circle on the sticker and through the duct wall below it.
03
Press the sight glass lens [H] firmly into the hole until it sits flush with the surface of the duct wall. The lens is designed to press-fit into the opening without adhesive.
04
Restore power to the unit. A blue glow visible through the sight glass confirms the lamp is operating. Close the air handler cabinet door.
Normal operation. The lamp is on and functioning correctly.
No power is reaching the unit. Check the power connection, transformer output, and circuit breaker.
Not seeing a blue glow after powering on? Use the troubleshooting table below to diagnose the issue before contacting support. Jump To TroubleshootingThe TruBlu UV-C lamp is rated for approximately 8,000 hours under continuous operation. Past this point, the lamp will continue to emit a visible blue glow but loses germicidal effectiveness. Replace on a 10-month schedule regardless of what the lamp looks like.
Guardian Club automatically ships you a replacement lamp every 10 months. Members receive 10% off replacement bulbs, automatic warranty coverage, and hassle-free delivery every cycle.
All replacement bulbs include a 14-day warranty from the date of delivery. Guardian Club members receive extended coverage of up to 6 months from delivery.
Free to join. Ships automatically. Keeps your warranty active. Join The Guardian Club Order Replacement Bulbs
www.BioShieldUV.com/club | Symptom | Likely Cause | Solution |
|---|---|---|
| Red indicator light | Lamp fault, end of life, or loose 4-pin connector | Reseat the 4-pin connector at both ends. If the lamp is older than 10 months, replace it. If the red light remains after reseating and replacing the lamp, contact support. |
| No indicator light | No power reaching the unit | Check the power outlet, transformer output, and circuit breaker. Confirm the LED switch on the power supply housing is in the left (on) position. |
| No glow visible through sight glass | Lamp not operating or sight glass obstructed | Follow the same diagnostic steps as the red light symptom above. Confirm the sight glass lens [H] is fully seated and the viewing surface is clear. |
| Faint ozone smell on first use | Normal burn-in period | This is expected behaviour. The smell is produced by the UV-C lamp interacting with ambient air during the initial run and will dissipate within 24 to 48 hours of continuous operation. |
| Magnetic bracket will not hold | Non-ferrous (aluminum) mounting surface | Switch to the screw-mount method: snap the bracket apart at the joint, remove the magnet, and fasten the bracket directly to the duct wall with the included self-tapping screws [I]. |
| Condensation at the cable entry point | Cable gland not fully sealed | Re-tighten the locknut on the cable gland [E]. If the issue continues, apply aluminum foil tape around the full perimeter of the penetration. |
UV-C lamps contain a small amount of mercury and must be disposed of in accordance with local environmental regulations. Do not place used lamps in standard household waste unless your local waste management authority explicitly permits it.
Visit www.lamprecycle.org to find mercury lamp recycling locations near you, or www.earth911.com to locate your local or state waste management program.
Many hardware and home improvement retailers that sell UV or fluorescent bulbs also accept used bulbs for drop-off recycling at no charge. If no recycling option is available and local regulations allow, seal the lamp in a plastic bag before placing it in household waste collection.







WallPlug models are designed for homeowner installation and require no licensed technician or dedicated wiring. HVAC models connect directly to a 24VAC transformer and must be installed by a licensed HVAC technician or electrician. Installation by an unlicensed individual on an HVAC model voids the warranty.
Where exactly should I install the UV lamp?Mount the lamp 12 to 14 inches from the evaporator coil with a clear, unobstructed line of sight. Aim it at the center gap between the two angled coil panels — the most common site for mold accumulation.
The lamp has a visible blue glow. Is UV-C actually working?The visible blue light is a by-product of UV-C emission, not UV-C itself. As long as the lamp glows blue, it is emitting UV-C — but effectiveness drops significantly after 8,000 hours of operation, which is why we recommend 10-month replacement regardless of appearance.
Can I wire the unit to run only when the HVAC fan runs?No. The lamp must operate continuously to prevent mold growth during system-off periods. Wire to constant power, not the blower relay.
My unit is showing a red light. What do I do?Reseat the 4-pin connector at both ends. If the red light remains, replace the lamp. If it still shows red after replacement, contact support.
Will UV-C damage plastic or rubber components inside my system?UV-C can degrade some plastics and rubbers over time with direct exposure. Shield vulnerable components such as flex duct liner, foam insulation, and exposed wiring with aluminum foil tape before installation. Metal ductwork and components are unaffected.
Can I install this on non-metallic ductwork?Yes — use the non-magnetic surface alternative described in the installation guide. Remove the magnet from the bracket and fasten it directly to the duct wall with the included self-tapping screws.
What if my HVAC is a communicating system such as Nest or Ecobee?The BioShieldUV unit is wired independently of your thermostat or communicating system. It connects to the 24VAC transformer and runs continuously, so it has no interaction with smart thermostat control.
The unit smells strange on first use. Is that normal?Yes. A faint ozone smell during the initial 24 to 48 hours of operation is normal and dissipates on its own. This is a common by-product of a UV-C lamp interacting with ambient air.
How do I know when to replace the bulb?Replace every 10 months regardless of how the bulb looks. The visible blue glow does not indicate germicidal effectiveness — it only indicates that the lamp is powered.
Take replacement off your to-do list entirely. Guardian Club members receive automatic delivery on the right schedule. [Join for free →]
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