BioShieldUV® Magnetic (SL) Series Complete Installation Guide
Models covered: SL18 WallPlug | SL36 WallPlug | SL18-HVAC | SL36-HVAC
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Safety Instructions
Read every safety section below before touching any component. These warnings apply to all models and all installation environments.
UV Germicidal Lamp Safety
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.
Lamp Handling
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.
UV Material Exposure
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.
Electrical Safety
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.
Broken Lamp Hazard
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.
Location Restrictions
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.
What is in the Box
TruBlu™ UV-C Lamp
Germicidal UV-C bulb
Magnetic Holder
Steel mounting bracket with lamp holder
Power Supply
Wall adapter (WallPlug) or external ballast (HVAC)
Lamp Cable
4-pin keyed connector cable
Cable Gland
Threaded strain relief for duct wall (1″ hole)
Step Drill Bit
Creates 1″ cable hole (all models) & ½″ sight glass hole (HVAC)
Warning Sticker
ETL compliance sticker & drill guide
Viewport
Pressed into ½″ hole to view lamp
Self-Tapping Screws ×4
Non-magnetic surface mount & ballast mounting
Tap-In IDC Connectors ×2
No-cut wire connection to existing transformer wiring
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.
Non-Magnetic Surface Alternative
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.
Part 1: Magnetic Bracket and Lamp Installation
Review the safety precautions before proceeding.
Find a Suitable Location
Open the Air Handler Cabinet
- Select a mounting location on the interior back or side panel
- Ensure the lamp has a clear, direct line of sight to the evaporator coil
- Position the lamp 12 to 14 inches from the coil
- Aim the lamp directly at the coil for optimal performance
| 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 |
Clearance and Surface Requirements
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.
Placement Tips
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.
Attach the UV Lamp to the Magnetic Bracket
Connect the 4-Pin Lamp Cable
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.
Position the Magnetic Bracket
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 →
Part 2: Wiring Installation
Confirm your model before proceeding as wiring differs between WallPlug and HVAC models.
Drill the Cable Exit Hole
Using the included step drill bit [F], drill a 1" hole through the air handler cabinet wall.
- Position the hole as low as practical
- For WallPlug models, drill near an accessible outlet
Install the Cable Gland
Insert the cable gland [E] into the hole from the outside of the cabinet.
Thread the locknut from the inside and tighten until secure.
- Choose a location that allows clean cable routing
Route the Cable
Model-Specific Power Connection
WallPlug Models
SL18-WallPlug and SL36-WallPlug
- Inside the cabinet, connect the wall adapter cord [C] to the lamp cable [D]. Align the square connectors and press firmly until the latch clicks.
- Ensure connections are dry and positioned away from any condensate drip paths.
- Plug the wall adapter into a nearby outlet
Important: The unit must remain powered at all times, even when the HVAC fan is off. Continuous operation prevents mold growth during system-off periods.
To prevent electric shock, match the wide blade of the plug to the wide slot of the outlet.
Pour éviter les chocs électriques, introduire la lame la plus large de la fiche dans la fente la plus large.
HVAC Models
SL18-HVAC and SL36-HVAC
- Mount the ballast [C] inside the air handler cabinet, in the electrical / control-panel section where the control board and 24V transformer are located. Position it around a corner or behind a panel partition so it is NOT in the direct line-of-sight of the UV lamp, and out of the coil airstream. Secure with the included self-tapping screws [I] on a flat metal surface.
- Connect the ballast to a dedicated 24VAC transformer using the tap-in connectors [J].
- Connect the ballast output to the lamp cable [D] through the cable gland.
Important: Connect to constant power, not the blower relay. The lamp must operate continuously for effective coil and drain pan protection.
To prevent electric shock, match the wide blade of the plug to the wide slot of the outlet.
Pour éviter les chocs électriques, introduire la lame la plus large de la fiche dans la fente la plus large.
Part 3: Monitoring Lamp Operation from Outside the Duct
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.
Apply the Warning Sticker
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.
The sticker reads: WARNING UV LIGHT SOURCE — This cover is provided with an Interlock to reduce the risk of ultraviolet radiation exposure. Disconnect power before servicing.
Do not remove or cover this sticker. It satisfies ETL safety marking requirements and must remain visible for the life of the installation.
Drill the Sight Glass Hole
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.
Install the Sight Glass Lens
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.
CAUTION: UV LIGHT SOURCE – KEEP PROTECTIVE BARRIER IN PLACE. The sight glass lens is a UV-C barrier. Do not remove or operate the unit with the lens missing.
Power On and Verify
Restore power to the unit. A blue glow visible through the sight glass confirms the lamp is operating. Close the air handler cabinet door.
Indicator Reference
Blue glow through sight glass / Blue LED
Normal operation. The lamp is on and functioning correctly.
No light
No power is reaching the unit. Check the power connection, transformer output, and circuit breaker.
Red
Lamp at or near end of life, or lamp fault. Reseat the 4-pin connector; if the lamp is over 10 months old, replace it.
Not seeing a blue glow after powering on? Use the troubleshooting table below to diagnose the issue before contacting support.
Replace Your Bulb Every 10 Months
The 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.
Replacement Procedure
- Turn off power to the unit by unplugging the adapter (WallPlug) or disconnecting the transformer (HVAC).
- For HVAC models, confirm through the sight glass that there is no glow before opening the cabinet.
- Open the air handler cabinet. Put on gloves and safety glasses before reaching inside.
- Disconnect the 4-pin connector from the existing lamp, then remove the lamp from the bracket [B].
- Seat the new TruBlu™ replacement lamp in the bracket and reconnect the 4-pin connector until it clicks.
- Close the cabinet and restore power. Confirm the blue LED or blue sight glass glow before leaving the installation.
Use ONLY BioShieldUV TruBlu™ replacement lamps. Using third-party lamp types voids the warranty and the ETL listing for the unit.
Never Miss a Replacement with Guardian Club
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.
www.BioShieldUV.com/club
Troubleshooting
| 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. [Read more about why this happens →] |
| 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 Lamp Disposal
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.
Frequently Asked Questions
Do I need a professional installer?
Where exactly should I install the UV lamp?
The lamp has a visible blue glow. Is UV-C actually working?
Can I wire the unit to run only when the HVAC fan runs?
My unit is showing a red light. What do I do?
Will UV-C damage plastic or rubber components inside my system?
Can I install this on non-metallic ductwork?
What if my HVAC is a communicating system such as Nest or Ecobee?
The unit smells strange on first use. Is that normal?
How do I know when to replace the bulb?
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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