Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Guardsman Vent Sanitizing: The Aurora Owner’s Guide
Guardsman vent sanitizing systems in Aurora typically run $280-$420 installed for a full sanitizing treatment with replacement components, and we stock Guardsman-compatible parts for same-day service across the metro area. Most Aurora homeowners discover the system needs attention when they notice persistent mustiness returning within weeks of a standard cleaning, or when their HVAC technician points out biofilm buildup in the plenum during routine maintenance. The Guardsman UV-C sanitizing modules we install are sized for residential ductwork common in Aurora’s 2015-2022 builds, where tighter envelope construction traps moisture and creates conditions standard cleaning alone won’t fix.
Which Guardsman Models This Applies To
Guardsman produces three residential sanitizing product lines: the GMS-100 series (single-lamp, 9-watt UV-C), the GMS-200 series (dual-lamp, 18-watt with photocatalytic oxidation), and the commercial-grade GMS-Pro line occasionally found in larger Aurora homes with zoned systems. The label is mounted on the lamp housing, not the ballast, and lists a four-digit date code (format: MMYY) that tells you whether you’re looking at the original 2016-2019 lamp design or the revised 2020+ model with the sealed quartz sleeve.
Here’s where compatibility gets specific: the 2016-2019 GMS-100 lamps measure 11.25 inches from ceramic end to ceramic end, while the 2020+ revision measures 11.5 inches. That quarter-inch difference matters because the spring-mount brackets in Aurora’s Lennox and Carrier systems, common in homes near the Aurora Hills Golf Course, have fixed slots that won’t accept the longer lamp without bracket modification. We carry both lamp lengths and the correct bracket adapters on our trucks. For the GMS-200 series, the photocatalytic grid (the honeycomb titanium-dioxide component) is a separate wear item with its own part number, and it’s where we see the most premature failure in Colorado’s dry climate, the grid desiccates and flakes rather than saturating evenly.
CleanRun Air Duct Cleaning Aurora is an independent service provider, not affiliated with Guardsman. We source OEM Guardsman lamps and grids through standard HVAC distribution channels, and we also stock aftermarket equivalents from Abatement Technologies that meet the same 253.7 nanometer UV-C output specification. The OEM lamps carry a 12-month manufacturer defect warranty; our aftermarket equivalents carry the same 12-month term through our supplier. We quote both options in writing before any work starts.
Signs Your Guardsman Vent Sanitizing Is Failing

- The “clean sock” smell returns within two weeks of duct cleaning. A functioning Guardsman lamp produces a faint ozone scent for 24-48 hours after activation, then nothing. If you’re noticing mustiness or a wet-dog odor cycling back through registers, the UV-C output has likely dropped below effective germicidal levels. The lamp still glows purple, but at insufficient intensity.
- Visible biofilm or slime at register openings, especially on second-floor returns. Aurora’s elevation means lower boiling points and faster evaporation, but in homes with whole-home humidifiers set above 35% RH, we see biofilm colonize the first elbow downstream of the humidifier pad. The Guardsman lamp should prevent this; its failure lets organic matter establish colonies in the galvanized trunk line.
- Your HVAC filter loads faster than the manufacturer interval. A dead or weak sanitizing lamp lets mold spores and bacterial fragments circulate and aggregate on the filter media. We pulled a filter from a home near Southlands last month that was rated for 90 days and clogged at 34 days; the GMS-100 lamp in that system was producing 40% of rated UV output.
- The indicator light on your air handler shows green, but the lamp is cold. The LED on Guardsman ballast housings indicates power to the ballast, not lamp function. We’ve found lamps with intact filaments that won’t strike an arc due to electrode degradation, a failure mode more common in Aurora’s voltage-fluctuation events during spring storm season.
- Annual energy bills creeping up with no equipment change. A failing ballast draws excess amperage trying to maintain lamp ignition. The difference is small per hour, but across a 24/7 runtime schedule, we’ve measured 8-14% increases in auxiliary draw that trace back to degraded ballast components.
Before
AfterReplacement Cost & What’s Included
| Service | Price Range | What’s Included |
|---|---|---|
| GMS-100 single-lamp replacement (OEM) | $280-$340 | Lamp, quartz sleeve inspection, ballast output test, bracket alignment, photo documentation |
| GMS-100 single-lamp replacement (aftermarket) | $240-$290 | Same scope with Abatement Technologies equivalent lamp |
| GMS-200 dual-lamp with grid replacement | $380-$420 | Both lamps, photocatalytic grid, full plenum access, before/after photo record |
| Ballast replacement only | $180-$220 | Matched ballast, voltage verification, mounting hardware |
The range reflects access difficulty. A GMS unit mounted on a horizontal trunk in an unfinished basement takes 45 minutes; the same unit tucked behind a finished ceiling near the E-470 corridor’s tighter crawl spaces can run two hours with proper containment. Haven Standard Clause 1 applies: we deliver a written price before any panel comes off, and that price is the price. No per-vent add-ons, no “while we’re here” escalation. The 365-Day Done Right Promise covers both parts and labor, documented in writing on every job.
Every replacement includes our standard Documented Photo Record: the existing lamp condition, the plenum interior at the mounting location, and the installed replacement with output verification. You receive these as part of the job record, not as an upsell.
DIY or Call Us?

What you can safely check: confirm the lamp label model number against your HVAC documentation, verify the breaker labeled “air handler” or “furnace” is engaged, and inspect the quartz sleeve for visible cracks or calcium scaling from Aurora’s moderately hard water. Do not attempt to remove a lamp that has been running, the quartz operates at 800°F+ and retains heat for 15 minutes after power-down.
Where DIY goes wrong: UV-C lamps require precise output verification with a radiometer, not visual inspection. A lamp that “looks fine” can be producing 30% of rated germicidal output. Ballast matching is also model-specific; we’ve seen homeowners install generic 120V ballasts that overdrive Guardsman lamps, shortening lifespan from 9,000 hours to under 2,000. The electrical enclosure in most Aurora homes is live with 240V service to the air handler, a genuine hazard.
If you’re uncertain, call (720) 513-5159. We’ll show you the photo first, then we talk about what comes next. Free Second Opinion on any written estimate you already have, Haven Standard Clause 6.
FAQs
Rated lifespan is 9,000 hours, roughly 12 months of continuous operation. In practice, Aurora’s combination of high altitude (thinner air, slightly less heat dissipation) and voltage fluctuations during spring thunderstorms reduces effective lifespan to 8,000-8,500 hours. We recommend annual testing, not just visual inspection. Call (720) 513-5159 to schedule output verification, estimates are free.
Individual components, yes, the complete assembly, rarely. A cracked quartz sleeve can be replaced independently; a degraded ballast can be swapped. But if the lamp housing itself shows heat distortion or the mounting bracket has corroded through, component-level repair exceeds replacement cost and won’t carry a meaningful warranty. We assess this in writing before any work starts. Call (720) 513-5159 for an exact quote.
Most residential replacements take 60-90 minutes from truck arrival to final output test. Access is the variable, a basement-mounted GMS-100 on an open trunk line runs shorter; a GMS-200 behind a finished soffit in a two-story home near Tollgate Crossing runs longer. We quote time and price together in writing before starting. Call (720) 513-5159 to schedule.
Yes. We carry GMS-100 and GMS-200 lamps in both OEM and aftermarket configurations, replacement quartz sleeves, matched ballasts, and photocatalytic grids for the GMS-200 series. For the less common GMS-Pro commercial line, we can typically source within 24 hours through our Denver distribution partner. Same-day service is standard for residential models across Aurora. Call (720) 513-5159 to confirm availability for your specific model.
Written by Tomas Reyes, Owner & Lead Technician, CleanRun Air Duct Cleaning Aurora at CleanRun Air Duct Cleaning Aurora, serving Aurora and nearby areas.




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