Fast, same-day worry-free repairs. Certified professionals. ⭐⭐⭐⭐⭐ 5-Star rating based Google and Housecall Pro reviews.
Quick overview — who we are & what we do
We provide specialized rooftop unit repair, comprehensive RTU services and commercial HVAC repair for commercial properties, ensuring your facility remains climate-controlled and energy-efficient. Our team delivers fast diagnostics, advanced component-level repairs, and full crane-coordinated logistics for even the most complex mechanical failures.
Federally Certified
EPA Universal Certified. This is the highest level of certification provided under the EPA’s National Recycling and Emissions Reduction Program. It authorizes A/C Dr. Naz to handle refrigerants for all types of equipment, from small residential ACs to the most complex industrial refrigeration systems.
HVAC/R Expertise
HVACR certification is a professional credential that demonstrates an individual has completed formal training and met industry standards in heating, ventilation, air conditioning, and refrigeration systems.
Our RTU Repair Services
Full diagnostics & failure analysis
Before turning a wrench, we perform a deep-system analysis to identify the root cause of failure. Our process includes testing static pressure, checking subcooling and superheat levels, and assessing overall system performance.
- What we inspect:
- Controls: Integrated Logic Boards and thermostat communication.
- Economizers: Damper motor torque and enthalpy sensors.
- Compressors: Ohming out windings and checking acid levels in oil.
- Mechanical: Blower belts, pulley alignment, and bearing lubrication.
- Drainage: Condensate P-traps and pan integrity.
Deliverable: You receive a detailed digital diagnostic report and a transparent repair estimate before work begins.
Electrical & controls repairs
RTU electrical systems are complex. We troubleshoot everything from high-voltage supply issues to low-voltage control loops.
- Examples: * Replacement of pitted contactors and heavy-duty starters.
- Transformer testing and control board troubleshooting.
- BAS Interfacing: Ensuring your RTU communicates correctly with Building Automation Systems and VFDs (Variable Frequency Drives).
Mechanical repairs & components
We handle the heavy lifting of mechanical restoration to extend the life of your equipment.
- Examples: * Semi-hermetic and scroll compressor replacements.
- High-static fan motor upgrades and precision shaft alignment.
- Vibration isolation and bearing replacements to reduce noise and wear.
Refrigerant system service
Our technicians are experts in closed-loop refrigeration chemistry. We provide precision leak detection using electronic halogen sniffers or ultrasonic tools, followed by EPA-compliant recovery, evacuation to 500 microns, and exact refrigerant recharging.
Economizer, airflow & dampers
Proper ventilation is key to indoor air quality (IAQ). We calibrate outdoor air dampers, replace failed actuators, and diagnose “free cooling” cycles to ensure your economizer isn’t wasting energy by fighting the mechanical cooling stage.
Rooftop logistics & crane operations
When a unit requires a full swap or a heavy component lift, we manage the logistics. This includes sourcing custom curb adapters, ensuring proper roof flashing to prevent leaks, and coordinating safe crane lifts with minimal disruption to your business operations.
Permits, roof access & safety: What building owners need to know
Navigating local mechanical codes is essential for compliance. Generally, a permit is required for any major component replacement (like a compressor) or a full unit change-out.
What we handle:
- Acquisition of mechanical and electrical permits.
- Coordination with structural engineers for curb weight verification.
- Rigging and safety zone management during crane lifts.
What the owner provides:
- Clear roof access (hatch keys or ladder safety anchors).
- Clearance around the unit for technician safety.
- Notification to tenants regarding brief power cycles or crane presence.
Building Manager Checklist:
- Verify roof warranty requirements (to ensure repairs don’t void membrane coverage).
- Ensure fall protection/guardrails are up to OSHA standards.
- Confirm electrical disconnects are accessible and not obstructed.
Commercial case studies / recent projects
Office tower RTU overhaul
- Problem: High energy bills and inconsistent cooling across the 4th floor due to a failed VFD and seized economizer dampers.
- Solution: Replaced the variable frequency drive, installed new Honeywell actuators, and recalibrated the BAS.
- Impact: 18% reduction in monthly kW consumption and eliminated hot/cold spot complaints.
Restaurant RTU emergency repair
Impact: Zero downtime for the lunch rush; kitchen temperatures stabilized within 45 minutes of the repair.
Problem: A critical kitchen RTU failed on a Saturday morning, threatening food safety and kitchen comfort.
Solution: Same-day service identified a failed contactor and a grounded blower motor. Components were replaced from truck stock.
Maintenance plans — packages & benefits
Regular maintenance is the only way to prevent “emergency-only” repairs. We offer scalable plans designed for the Pacific Northwest climate.
Quarterly preventive plan
Recommended for coastal/marine climates where salt air or high humidity accelerates corrosion.
- Filter replacement (MERV 8 or 13).
- Evaporator and condenser coil chemical cleaning.
- Condensate drain line clearing and biocide tablets.
- Belt tensioning and pulley alignment.
- Amp draw analysis on all motors.
- Economizer calibration and damper lubrication.
- Refrigerant charge verification.
- Detailed quarterly performance report.
Biannual tune-up
Focuses on seasonal transitions (Spring/Fall) to ensure peak performance.
- Full heating and cooling cycle testing.
- Electrical connection tightening and contactor inspection.
- Thermostat/BAS calibration.
- Basic coil cleaning (air-blown or light wash).
- Blower assembly inspection.
- Lubrication of all moving parts.
Custom commercial maintenance
Scalable for portfolios with multiple sites or high-tonnage requirements.
- Tailored scope of work based on equipment age and critical load.
- Priority same-day service scheduling.
- Dedicated account management.
Technical compatibility & OEM notes
The company services all major commercial brands, including Carrier, Trane, Lennox, York, and Goodman. We prioritize OEM (Original Equipment Manufacturer) parts to maintain factory warranties and ensure precise fitment. However, for out-of-warranty systems, we can provide high-quality aftermarket alternatives that meet or exceed original specifications to help manage repair costs.
Certifications & trust: Commercial Rooftop Unit Repair
Certifications we hold
- EPA Section 608 Universal Certification (Safe refrigerant handling).
- HVAC/R Certified Specialist.
- Licensed, Bonded, and Insured.
- Goodman Pro Dealer Status.
About our company
A/C Dr. Naz is a premier commercial mechanical service provider serving the Snohomish and King County regions. We operate a specialized fleet equipped for heavy-duty commercial repairs, serving everything from retail strips to large-scale industrial warehouses.
- Service Philosophy: Professional technical authority combined with same-day service reliability.
“Our server room went down when the RTU failed. The team arrived the same day and had us back online before the equipment overheated. Professional and fast.” — Everett Business Owner
Service area — commercial RTU repair near you
Our team provides specialized commercial HVAC services across the Greater Puget Sound area. We prioritize same-day service for facilities located within our primary service corridors in Snohomish and King Counties.
Primary service cities:
- Snohomish County: Marysville, Everett, Snohomish, Lake Stevens, Arlington, Edmonds, and Lynnwood.
- King County: Seattle, Shoreline, Bellevue, Kirkland, Redmond, Woodinville, and Bothell.
Not sure if you’re in our range? We frequently handle mechanical projects for industrial sites and office parks throughout the I-5 and I-405 corridors.