Thor Motor Coach-Avanti RV Exposed: Water Leaks, Slide Failures, Electrical Gremlins, Service Delays

Introduction and Model Background

AI-powered research tools have systematically collected and analyzed public information to produce this report. The Thor Motor Coach Avanti is a compact, fuel-efficient Class A motorhome originally developed under the Damon brand (a Thor subsidiary) and later folded into Thor Motor Coach when the companies consolidated around 2010–2011. Marketed as a sleek, aerodynamic “European-inspired” coach with diesel efficiency and upscale finishes in a smaller footprint, the Avanti attracted buyers who wanted Class A amenities without the bulk. Although this model is now discontinued, many used units are still circulating in the market.

Industry reputation of the Avanti is mixed. Owners often praise easy driving manners for a Class A, clever floor plans, and contemporary looks for its era. However, recurrent patterns of owner complaints—particularly around build quality, water intrusion, slide-out alignment, electrical gremlins, and service/warranty friction—have followed this coach and the broader Thor brand across multiple forums and review platforms. Because the Avanti spans the Damon-to-Thor transition, shoppers should search under both “Damon Avanti” and “Thor Motor Coach Avanti” to gather a full picture of owner experiences and recall history.

Where to Find Unfiltered Owner Feedback (Start Here)

Before you fall in love with a floor plan, immerse yourself in owner communities and public records. We recommend starting with:

• Search for Thor Motor Coach Avanti Facebook Groups (avoid direct links; join multiple groups to compare experiences). Ask members to share repair invoices and timelines.
• YouTube owner videos: Thor Motor Coach Avanti Problems. Long-form owner walk-throughs often reveal common weak points.
• Google: Thor Motor Coach Avanti Problems for a broad sweep of reviews, forums, and independent blogs.
• BBB complaints and company responses related to Thor Motor Coach (search by model and brand).
• Reddit threads for candid user-to-user troubleshooting:
  • r/rvs: Thor Motor Coach Avanti Problems
  • r/RVLiving: Thor Motor Coach Avanti Problems
  • r/GoRVing: Thor Motor Coach Avanti Problems
• RVInsider owner-written reviews: Thor Motor Coach Avanti Problems
• Good Sam Community forum threads: Avanti Problems
• RVForums.com, RVForum.net, and RVUSA Forum for archived model-specific discussions.
• NHTSA recall database: Thor Motor Coach Avanti. Also search “Damon Avanti” and chassis supplier by year if your VIN suggests a Workhorse or other platform.
• PissedConsumer main portal (search manually for “Thor Motor Coach Avanti” and “Damon Avanti” once on the site).

Investigative tip: Independent consumer advocates such as Liz Amazing are increasingly documenting systemic RV quality issues. Browse her channel and search for your prospective model to learn inspection strategies and buyer pitfalls: Watch investigative RV buying advice by Liz Amazing.

Have you owned or shopped an Avanti? What happened in your case?

Before You Buy: Get a Third-Party RV Inspection

Buying used? A third-party inspection is your leverage before signing. Once the dealer has your money, many owners report long waits for repairs and postponed trips while the coach sits for months. Hire an NRVIA-certified or equivalent independent inspector to document defects, estimate repair costs, and negotiate fixes or price adjustments pre-delivery. If you skip this step, the service department may place you at the back of the line, especially during peak season.

• Search locally: RV Inspectors near me
• Ask the inspector to test: roof integrity, moisture levels, slide mechanisms, chassis/engine diagnostics, charging systems, inverter, generator load tests, HVAC systems, and all plumbing/LP systems under pressure.
• Make the sale contingent on passing the inspection or on the dealer completing a punch list before delivery.

Consumer advocates stress this step repeatedly. For a straightforward overview of what to test and why, search on Liz Amazing’s channel: Independent RV inspections: what to look for.

Commonly Reported Problems and Risk Areas

The Avanti’s age and discontinued status place extra pressure on buyers to verify condition and parts availability. Below are recurring themes across owner reports on forums, reviews, and video testimonials. For each topic, we include research links so you can verify patterns in current discussions.

Body Integrity: Water Intrusion, Sealant Failure, and Delamination

Water intrusion is among the most damaging and expensive issues reported on used coaches. For Avanti-era Thor/Damon units, owners describe periodic resealing needs at roof seams, front and rear cap transitions, slide facias, and marker lights. Neglected sealant can lead to soft floors, swollen cabinetry, electrical faults, and sidewall delamination—problems that cost far more to remediate than routine maintenance would.

• Research threads: Thor Motor Coach Avanti Water Leaks
• Owner videos: Avanti water intrusion/roof leaks
• Forum discussions: Good Sam threads on water leaks

Practical check: Insist on a moisture meter sweep and thermal imaging during a pre-purchase inspection. Verify that slide toppers are intact and that weep holes aren’t clogged. Recurrent leaks often correlate with extended service delays and trip cancellations. If you’ve had this issue on your Avanti, can you share how it was resolved?

Slide-Out Mechanisms: Binding, Misalignment, and Swollen Floors

Multiple Avanti-era owners report slide-outs that bind or rack under load, especially after minor water intrusion or if seals stiffen. In this vintage, heavier slides paired with lighter-duty mechanisms sometimes led to chronic misalignment, sheared bolts, damaged racks, or wavy slide floors.

• Evidence search: Avanti Slide Problems
• Owner videos: Slide repair experiences
• Community threads: RVInsider reports mentioning slides

Buyer tip: Inspect slide floors for swelling, check alignment at full extension/retraction, and listen for uneven motor load. Poor slide performance can cascade into leaks and structural stress, adding thousands to remediation costs.

Electrical and Multiplex Control Issues

Owners of Thor/Damon coaches from this era frequently report electrical “gremlins,” such as intermittent lighting, nonresponsive multiplex wall switches, failing converter/chargers, and parasitic battery draws. When water intrusion is present, the rate of electrical problems increases dramatically.

• General complaints: Electrical Problems: Avanti
• Forum help: RVForums.com (search for “Avanti electrical”) and RVForum.net

Inspection musts: Load test house batteries, verify charging from alternator, shore, and generator. Check for proper breaker labeling, clean grounds, intact GFCIs, and insulation integrity behind damp areas. An electrical review by a third party can prevent cascading failures later—search RV Inspectors near me.

Chassis and Powertrain: Engine Cooling, Emissions, and Steering Feel

Depending on the year, the Avanti could be built on different chassis configurations. Prospective buyers should determine the exact chassis and engine combination by VIN. Reports across this class (compact Class A diesel/gas) include:

• Front-engine diesel heat management challenges and fan/engine noise reported by some owners on grades.
• Emissions equipment (EGR/DPF) maintenance burdens on certain diesel engines of the era, potentially requiring frequent cleaning cycles or component replacement if usage is mostly short trips.
• Steering wander, body roll, and driver fatigue without suspension upgrades (track bars, steering stabilizers, sway bar improvements).

Evidence sources and due diligence:

• Google: Avanti Engine Problems
• YouTube: Handling/Steering issues
• NHTSA recall search; also try searches for “Damon Avanti” and the exact chassis brand/year.

Buyer tip: Obtain a full chassis inspection by a heavy-truck or RV-specialty shop, including alignment, bushing condition, brake system health, and an engine scan for stored emissions faults. Road test on highway and grades with crosswinds if possible.

Weight, Cargo Carrying Capacity (CCC), and Axle Loading

Compact Class A coaches sometimes leave slim CCC margins once full water, fuel, passengers, and gear are aboard. Owners have reported front-axle loading close to limits with full tanks or heavy aftermarket add-ons. Overloading is a safety hazard, accelerates tire and brake wear, and can void insurance claims after an accident.

• Research: Avanti Weight/CCC Problems
• Community experiences: Reddit threads on loading

What to do: Weigh each wheel position at a CAT scale or RV rally scale, then set tire pressures from the tire manufacturer load table. Do not accept delivery until you can confirm realistic CCC with your typical camping gear.

House Systems: Plumbing Leaks, Fixtures, and Tank Sensors

Across Thor/Damon coaches from this period, owners frequently report drip leaks at P-traps, loose fittings behind walls, toilet seal failures, and tank sensors that become unreliable due to residue buildup. While not always catastrophic, these issues compound if left unfixed and are often cited in 1-star reviews for hassle and repeated shop visits.

• Avanti Plumbing Problems
• Tank sensor troubleshooting videos

Inspection checklist: Pressurize the system and check for drips at all joints; test tanks for accurate readings when empty/full; confirm water pump cycling behavior; and ensure any bypass valves for winterization are not leaking air.

HVAC, Generator, and Dash AC Performance

Owners often describe dash AC underperforming in hot climates, especially on dark, low-profile Class A front caps. Roof ACs can also struggle if ducting is leaky or filters are neglected. Onan generator service schedules are sometimes missed in prior ownership, leading to hard starts or load dropouts.

• Avanti AC Problems
• Generator issues on Avanti

Preventive approach: Verify generator service history, run the unit under 50–75% load for an hour during inspection, and check roof AC temperatures at vents. Dash AC function should be assessed at highway speeds.

Fit and Finish: Cabinetry, Trim, and Furniture Wear

Consumers often cite misaligned cabinet doors, squeaks/rattles, peeling upholstery (particularly bonded leather of the era), and trim pieces coming loose. While each item may seem minor, the pattern indicates workmanship and adhesives that may not have aged well, requiring ongoing owner intervention.

• Quality Problems: Thor Motor Coach Avanti
• Owner reviews highlighting fit/finish

If an Avanti you’re considering “looks” great online but shows multiple cosmetic defects in person, treat it as a signal to investigate deeper systems for deferred maintenance or water intrusion. If you’ve battled trim or upholstery failures, what fixes lasted for you?

Warranty, Parts Delays, and Service Network Friction

While your prospective Avanti is likely out of original warranty, the pattern of service delays and parts backorders in the Thor ecosystem is relevant for used buyers as well. Many owners report long waits for factory parts, difficulty getting appointments at busy dealers, and slow turnaround on complex repairs—particularly slide mechanisms, bodywork, and electrical harnesses. Some buyers report months-long delays that cancel multiple planned trips.

• BBB complaints and Thor responses
• Service delay experiences: Avanti

Practical step: If buying from a dealer, negotiate guaranteed service timelines or pre-delivery completion of all punch list items. Otherwise, you risk losing your camping season while the coach sits in a queue.

Recall Awareness and Safety Risks

Avanti-era coaches may be subject to recalls on chassis components (brakes, steering), appliances (refrigerators and awnings), and safety equipment (seatbelts). Because the Avanti spans different brand labels and potential chassis suppliers, search thoroughly:

• NHTSA: Thor Motor Coach Avanti recalls
• Also search for “Damon Avanti,” the chassis brand and year, and any major appliances (Norcold/Dometic refrigerators, Lippert components) that appear in your unit.
• Video summaries and owner experiences: Avanti Recall discussions

Unrepaired recalls pose safety hazards and can complicate insurance claims after an incident. Ask the seller for a VIN-specific recall clearance letter and proof of recall completion.

Product and Safety Impact Analysis

How do these reported defects affect real-world safety and costs?

• Water intrusion compromises structural subfloors, walls, and wiring. Once rot sets in, repair costs become disproportionate to the coach’s market value.
• Slide failures can trap owners at campsites if the room won’t retract, necessitating mobile techs or tows. Binding slides can also tear seals and invite further water damage.
• Electrical faults elevate fire risks and cause unpredictable failures of critical systems (refrigeration, HVAC, lighting) while traveling.
• Chassis and brake issues pose direct safety risks at highway speeds. Steering vagueness induces fatigue and increases accident risk; emissions/diesel faults can lead to derate (reduced power) at inopportune times.
• Overloading stresses tires and braking systems, increasing blowout and stopping-distance risks.
• Service delays result in trip cancellations, lost deposits, and added costs for alternative lodging or storage while waiting for parts/repairs.

To minimize risk exposure, buyers should prioritize thorough inspections and insist on documentation confirming repairs and maintenance. For a practical checklist, check independent educator content and search within channels like Liz Amazing’s RV buyer guides. And if you’ve faced safety-critical failures on an Avanti, will you describe what happened?

Legal and Regulatory Warnings

Buyers and current owners have several legal pathways when defects or safety issues persist:

• Magnuson-Moss Warranty Act (MMWA): Governs written warranties on consumer products. If a dealer or extended warranty company fails to honor covered repairs within a reasonable time, you may have claims under federal law.
• State Lemon Laws: Most state lemon laws emphasize new vehicles, but some states extend protections to RVs or components (e.g., chassis). Check applicability for your state and whether your claim timeline has lapsed for a used Avanti.
• Uniform Commercial Code (UCC): Implied warranties of merchantability/fitness may apply to used sales unless lawfully disclaimed. Misrepresentation (e.g., nondisclosure of known water damage) can also trigger state consumer protection claims.
• Federal Trade Commission (FTC): Deceptive claims in advertising or sales practices can be reported to the FTC, particularly if a dealer misleads buyers about condition or recall status.
• National Highway Traffic Safety Administration (NHTSA): Safety defects and unaddressed recalls can be reported and tracked here.

Practical legal advice:

• Document everything: inspections, emails, texts, repair orders, and invoices. Patterns of failed repair attempts strengthen your case.
• If arbitration is required by contract, review procedural rules and deadlines immediately after purchase.
• If a safety defect is involved (brakes, steering, fuel, fire risk), stop using the coach until it’s repaired; notify NHTSA and your state AG’s consumer protection division if the seller refuses reasonable remediation.

If you’ve pursued a warranty or legal claim on an Avanti, can you share what worked and what didn’t?

Ownership Realities: Parts, Depreciation, and Resale

As a discontinued model, the Avanti faces parts and fitment hurdles. Many components are generic (appliances, ACs, water heaters), which helps. But body-specific trim, slide structures, and certain electrical harnesses may be limited to salvage yards or long lead times from suppliers.

• Expect lower resale values versus premium brands with stronger quality reputations and smaller failure patterns.
• Factor into your budget: recurring sealing, possible slide maintenance, electrical cleanup, and potential suspension upgrades to improve drivability.
• Independent forums remain your best resource for workarounds if OEM parts are discontinued.

Research threads on depreciation vs. upkeep: Thor Motor Coach Avanti owner reviews.

Pre-Purchase Inspection Roadmap (Actionable)

Make the inspection non-negotiable. It’s your only leverage before funds transfer. If you fail to secure repairs before signing, many dealers will delay—sometimes for months—once they have your money.

• Roof and Walls: Moisture meter and thermal imaging; inspect roof membrane, cap joints, and all penetrations; inspect behind cabinets for hidden dampness.
• Slides: Operate under load; check alignment, seals, topper condition, and floor rigidity.
• Chassis: Alignment, brakes, suspension bushings, steering components; engine diagnostics for emissions/DTCs.
• Electrical: Verify all AC/DC systems; battery age and load tests; converter/inverter operation; GFCI/transfer switch behavior.
• Plumbing/LP: Pressure test, look for leaks, confirm hot water recovery, and test tank sensors after cleaning.
• Generator/HVAC: Run under load; check temperature deltas at vents; listen for compressor cycling or surging.
• Recalls: Match VIN to NHTSA and secure proof of completion.

Find certified inspectors here: RV Inspectors near me. Also search “Damon Avanti inspection checklist” on forums for model-specific pointers: Damon Avanti Inspection Checklist.

Verifying Consumer Reports and Building Your Own Evidence File

To separate isolated incidents from patterns, cross-compare complaints on multiple platforms and look for consistent failures. Use these targeted searches when validating specific claims:

• General issues: Thor Motor Coach Avanti Issues
• Owner reviews: RVInsider: Avanti Problems
• Slides: YouTube: Slide Problems
• Water leaks: Good Sam: Water Leaks
• Electrical: Reddit: Electrical Problems

For a primer in spotting red flags during walk-throughs, search an RV consumer advocate channel for “pre-purchase inspection walkthroughs and punch lists”: Liz Amazing’s buyer education videos. And please add your Avanti lessons learned so other shoppers benefit from your experience.

Balanced Notes: Improvements and Resolved Issues

To be fair, some owners report good experiences with ride quality upgrades (sway bars, steering stabilizers) and successful leak remediation after comprehensive reseal work. Others report that once initial shakedown repairs were completed, their Avanti served reliably for years of moderate use. Recalls on major appliances and awnings, when completed properly, reduce risk significantly. As with any used coach, prior owner care and storage conditions make an outsized difference in long-term reliability.

However, the overall pattern in publicly available owner feedback continues to emphasize caution around water intrusion, slide mechanisms, electrical reliability, and long service delays. These are not trivial; they can derail travel plans and consume significant budgets.

Final Buyer Guidance

• Budget realistically for catch-up maintenance on a discontinued model; make the sale contingent on a passing third-party inspection.
• Confirm CCC and axle weights with your gear aboard; don’t rely on brochure numbers.
• Verify recall completion by VIN and retain documentation for insurance and resale.
• Expect parts lead times and identify a reputable independent RV service shop before you need one.
• Document all defects on delivery; if buying through a dealer, secure repair timelines in writing.

If you’ve researched or owned the Avanti, what would you tell a first-time buyer?

Summary and Recommendation

Publicly available consumer feedback and forum discussions consistently flag serious concerns with the Thor Motor Coach Avanti (and its Damon-branded predecessors) in the areas of water intrusion and body integrity, slide-out reliability, electrical system stability, and service/parts delays. While some units perform acceptably after thorough remediation and conscientious upkeep, the risk profile for shoppers—especially those new to RV ownership—is elevated compared to peers with stronger quality control reputations.

Based on the weight of consumer reports and the age/discontinued status of the Avanti, we do not recommend this model for buyers who are unwilling or unable to invest significant time and money into inspection, remediation, and ongoing maintenance. Consider widening your search to other brands or models with stronger reliability records and better-supported parts pipelines.

Lastly, your firsthand experience helps other shoppers make informed decisions. Will you share your Avanti story—good or bad?