Newmar Saw the Difference. You Will Too.

Factory Authorized Newmar Service & Warranty Repair

Newmar doesn't hand out factory authorization to just anyone. Out of thousands of RV shops across the country, only a handful of service-only centers have earned the right to carry Newmar's factory training and warranty authorization. 3R RV Service Center is one of them.

We didn't earn that by selling coaches off a lot. We earned it by fixing them — correctly, the first time, for over 20 years. Newmar recognized that the same hands-on expertise their owners depend on doesn't live at a dealership. It lives in a shop where every dollar comes from doing the work right.

Why That Matters For Your Coach

Your Newmar isn't a weekend camper. It's a handcrafted luxury motorcoach — built with full-body paint, custom cabinetry, multiplex electrical systems, Aqua-Hot or Oasis hydronic heating, HWH hydraulic leveling, Cummins diesel generators, and integrated coach management systems that tie everything together through a central control network. Some of the coaches that roll into our shop are worth more than most houses in this county. We treat them that way.

When something goes wrong on a Newmar, it's rarely a simple fix. A slide-out issue might be electrical, hydraulic, structural, or a combination of all three. An HVAC problem might trace back to the multiplex system. A water leak behind a full-wall slide can cause tens of thousands in damage if not caught and repaired by someone who knows where to look.

Most shops will tell you one of three things: "We don't work on those," "You need to take it back to the factory in Nappanee," or they'll take your money, keep your coach for months, and still not fix the problem.

That's why Newmar authorized us. So their owners don't have to deal with that.

Models We Service

We service all Newmar models, current and legacy:

Class A Diesel Pushers: King Aire, Essex, London Aire, Mountain Aire, Supreme Aire, Dutch Star, New Aire, Ventana, Northern Star, Kountry Star

Class A Gas: Bay Star, Bay Star Sport, Canyon Star

Super C: Grand Star, Freedom Aire, Summit Aire, Super Star

Whether your coach is a 2026 King Aire on a Spartan K3 tag axle or a 2005 Dutch Star on a Freightliner, we have the factory training and diagnostic capability to service it.

Factory Trained on Every System in Your Coach

This is what separates factory authorization from a shop that just says they'll work on Newmars. We don't outsource your systems to five different specialists. We handle it all under one roof, with factory training on every major component platform Newmar installs:

Hydronic Heating (Aqua-Hot / Oasis): Most Newmar diesel pushers from the Ventana up come equipped with Aqua-Hot or Oasis hydronic heating systems. We are certified on both platforms. Burner service, heat exchanger inspection, coolant system maintenance, zone valve diagnosis, and complete system troubleshooting.

Hydraulic Leveling & Slides (HWH): Most Newmar motorhomes use HWH hydraulic leveling and slide-out systems. We are HWH Certified. Pump and valve body service, cylinder repair, sensor calibration, touch pad and controller diagnosis, and complete hydraulic system troubleshooting.

Generators (Cummins Onan): Newmar coaches run Cummins Onan generators. We are Cummins Onan Certified. Annual service, load testing, fuel system repair, carburetor and governor service, voltage regulator diagnosis, alternator testing, and fault code diagnosis.

Electrical & Multiplex Systems: Newmar's multiplex and Total Comfort systems control lighting, HVAC, slides, leveling, and entertainment from centralized touch panels. We diagnose at the board and module level — not by swapping expensive components hoping to find the problem.

Plumbing & Waste Systems: Fresh, gray, and black water systems. ABS pipe repair, fitting replacement, valve service, pump diagnosis, water heater service, and leak detection. ABS joint cracking is a known issue on some model years — we inspect and repair properly.

HVAC & Climate Control: Roof air units, basement air systems, heat pumps, and integration with hydronic heating. Thermostat and zone control diagnosis through the multiplex system.

Slide-Out Systems: Full-wall hydraulic slides, Schwintek in-wall slides on some models, and hybrid configurations. Seal replacement, structural inspection, alignment, and complete mechanical and electrical diagnosis.

Roof, Exterior & Structure: Roof membrane maintenance, slide topper replacement, window seal service, compartment door adjustment, and water intrusion investigation. For full-body paint and collision repair, we work with Pro Body in Union, MO — they know these coaches and do quality work.

Common Problems We Fix

Water intrusion around slides — The most common and most expensive issue we see on Newmar coaches. Full-wall slides with deteriorated seals, improper slide topper drainage, or structural settling can let water behind walls where it causes hidden damage for months before you see it. We trace the leak source, assess the damage, and repair it properly.

Multiplex system faults — Lights, slides, HVAC, or generators not responding to the coach control panel. Could be a module failure, communication bus issue, or wiring fault. We diagnose at the system level, not by guessing at $500 modules.

Aqua-Hot or Oasis won't fire or heat — Could be burner, fuel delivery, sensor, or control board. We are certified on both systems and diagnose the actual failure.

HWH leveling or slide malfunction — Jacks won't level, slides won't extend or retract, or system throws codes. Could be hydraulic, electrical, or controller. We're HWH Certified and diagnose at the valve body and board level.

Generator won't start or faults under load — Common on coaches that sit between trips. Could be fuel starvation, carburetor varnish, low oil shutdown, control board fault, or internal alternator issue. We load-test and diagnose to the component level.

ABS plumbing failures — Cracked joints at glued fittings, particularly on coaches that see temperature cycling or road vibration. Known issue on certain model years. We inspect and repair with proper materials and technique.

Electrical system issues — Inverter failures, battery system problems, charging system faults, or wiring issues. Some Newmar coaches have had repeated inverter problems. We trace the root cause rather than just swapping the inverter again.

Slide seals leaking or torn — Allows water, bugs, and air intrusion. We replace with proper materials and verify alignment.

Coach sits for extended periods — Generator fuel system varnishing, tire flat spots, battery degradation, seal dry rot, and HVAC mold. We offer pre-trip inspections and recommissioning service for coaches coming out of storage, including generator service, oil changes, battery testing, seal inspection, and system checkout.

What To Expect

We diagnose the actual problem before recommending repairs. Every repair is inspected by an RVTI Level 4 Master Technician before your coach leaves. We don't guess, we don't swap parts hoping something sticks, and we don't keep your coach for three months without answers.

We work directly with Newmar's service support team for warranty authorization and parts ordering. Newmar's parts department typically ships in-stock items same day. If your coach needs something we don't have on the shelf, we'll give you an honest timeline — not a runaround.

We understand that most Newmar owners have been bounced between dealerships, general RV shops, and mobile techs who are in over their heads. That stops here. Newmar authorized us for a reason.

Contact

Stop chasing shops that can't help you. Call 3R RV Service Center at (636) 583-2244 or stop by our facility at 7819 Highway 47, Union, Missouri 63084. We're open Monday through Friday 8am-6pm and Saturday 8am-12pm.