Rooftop Unit Services in Downey, CA and Surrounding Areas

A commercial rooftop unit that is failing during summer heat is not just an equipment problem. It is an operational problem that affects employees, customers, inventory, and in some regulated industries regulatory compliance. When a rooftop unit starts short-cycling, losing cooling capacity, making loud mechanical sounds, or failing entirely, the business cannot afford to wait days for a technician. Downey Plumbing, Heating and Air Conditioning services, repairs, and replaces commercial rooftop HVAC units for property owners and managers throughout Downey and the surrounding Los Angeles County communities. Our licensed HVAC technicians (California Contractor License #731172, verified through the California Contractors State License Board) are experienced with all major commercial rooftop brands and respond to emergency calls around the clock. We are BBB A+ accredited, 4.8-star rated on Yelp by hundreds of verified customers, and highly rated on HomeAdvisor. We maintain the capacity to source parts quickly and minimize downtime for commercial clients. Call 562-646-1221 immediately for rooftop unit repair or service.

Contact Downey Plumbing with all of your rooftop unit needs including repair, maintenance, or replacement.

Qualified rooftop unit technicians are required for all maintenance, repairs and service for HVAC systems. Our expert technicians have been fully trained to handle routine repairs, major repairs and, if needed, replacement of rooftop units.

Technician was Very Supportive, Very Knowledgeable

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“Technician was very supportive, very knowledgeable in his skills. Showed interest in making sure the customer understands. Went above and beyond to explain my options. Thanks Downey Plumbing!”
- Cheryl S.

Expert Tips
- Joe Keays
Maintaining a comfortable indoor environment is crucial, and your rooftop unit plays a vital role. To ensure optimal performance, remember to schedule regular maintenance for your unit. Just like your car needs a tune-up, your rooftop unit requires professional attention too. Regular inspections, cleaning, and filter replacements will not only enhance its efficiency but also extend its lifespan. Don't wait for a breakdown; be proactive and invest in routine servicing. Trust our expert team in Downey, CA, to keep your rooftop unit running smoothly and your space comfortable year-round.
- Joe Keays
Rooftop Unit Services

We serve all of Southern California including Downey, Pico Rivera, Long Beach, Paramount, Commerce, South Gate, Lakewood and Bellflower. Call Downey Plumbing today if you need routine service or if you need our complete emergency services. We are the premier rooftop unit provider of sales, service and maintenance for all your rooftop HVAC needs.

Frequently Asked Questions

A rooftop unit, also called an RTU or package unit, is a self-contained HVAC system where all components including the compressor, condenser, evaporator, and air handler are housed in a single cabinet installed on the building roof. Conditioned air is delivered through ductwork that connects to the unit through a roof curb. Rooftop units are the standard HVAC configuration for commercial buildings in Southern California.
Downey Plumbing, Heating and Air Conditioning services rooftop units from all major commercial HVAC brands including Carrier, Bryant, Lennox, Trane, York, Daikin, and others. Our technicians are trained on a wide range of commercial rooftop equipment and carry commonly needed parts for major brands. Call [phone] to schedule rooftop unit service.
Rooftop units should receive professional preventative maintenance at least twice per year, ideally in spring before the cooling season and in fall before the heating season. Units in demanding environments, those serving critical spaces, or those with histories of frequent problems may benefit from quarterly maintenance.
Rooftop unit maintenance includes cleaning the condenser coil, inspecting and cleaning the evaporator coil, clearing the condensate drain pan and drain line, checking and replacing filters, inspecting and tightening electrical connections, testing capacitors and contactors, checking refrigerant charge, testing economizer operation, inspecting belts and bearings on belt-drive units, and testing heating function in gas or heat pump units.
Common causes of rooftop unit cooling failure include a failed compressor or compressor contactor, low refrigerant from a leak, a severely dirty condenser coil that cannot reject heat effectively, a failed condenser fan motor, a clogged evaporator coil, a failed economizer that is drawing in hot outdoor air, or electrical failures in the control circuit. Our technicians perform systematic diagnosis to identify the specific cause.
Yes. Downey Plumbing, Heating and Air Conditioning provides emergency commercial HVAC repair including rooftop units 24 hours a day, 7 days a week. A rooftop unit failure during summer heat affects every occupant of the building and requires immediate attention. Call [phone] now for emergency rooftop unit service.
An economizer is a component on commercial rooftop units that opens outdoor air dampers when outdoor conditions are suitable for free cooling, reducing the need to run the compressor. Economizer actuators, sensors, and dampers are subject to wear and can fail in the open position, which draws in hot outdoor air and dramatically reduces cooling effectiveness. Economizer inspection is part of every rooftop unit maintenance visit.
Yes. Downey Plumbing, Heating and Air Conditioning replaces commercial rooftop units of all types and sizes, handling crane coordination when needed for heavy units, curb adapter installation, duct reconnection, electrical reconnection, refrigerant charging, and commissioning. Call [phone] to schedule a rooftop unit replacement consultation.
A roof curb is the structural frame that the rooftop unit sits on, which provides the mechanical support and the weathertight connection between the unit and the building roof. The curb must match the unit footprint and be installed on a properly reinforced roof section. When replacing a rooftop unit, a curb adapter may be needed to match the new unit's footprint to the existing curb.
Yes. When replacing a rooftop unit, any compatible brand can be selected for the replacement. The new unit must be sized appropriately for the space it serves and compatible with the existing ductwork connection and electrical supply. Downey Plumbing, Heating and Air Conditioning evaluates these requirements and recommends replacement options. Call [phone] to discuss rooftop unit replacement.
Rooftop unit short-cycling, where the unit runs only briefly before shutting off and then restarting, is commonly caused by an oversized unit, refrigerant issues, a dirty evaporator coil causing high pressure, a failed economizer admitting too much hot outdoor air, thermostat problems, or control board failures. Systematic diagnosis identifies the specific cause.
Yes. Downey Plumbing, Heating and Air Conditioning services commercial rooftop units for restaurants throughout Downey and the surrounding area. Restaurants have high occupant loads and kitchen heat that demand reliable HVAC performance. We understand the operational importance of rooftop unit reliability for food service businesses. Call [phone] to schedule service for your restaurant's rooftop unit.
Yes. Commercial rooftop units are available as cooling-only, gas heating with electric cooling, and heat pump configurations. Most commercial rooftop units installed in Southern California are gas heat and electric cooling package units. Heat pump rooftop units are increasingly available for commercial applications and may qualify for efficiency incentives.
Commercial rooftop units typically last 12 to 20 years depending on the quality of the equipment, the maintenance history, and the operating environment. Units that receive consistent semi-annual maintenance last significantly longer than units that are serviced only when they fail.
Downey Plumbing, Heating and Air Conditioning provides upfront pricing after assessment. Commercial rooftop unit service costs depend on the unit size, the nature of the repair, and parts availability. Call [phone] to schedule a rooftop unit evaluation and receive a clear estimate.

The words out about Downey Plumbing!

“Downey Plumbing is our go-to for all our plumbing needs. We discovered them after another plumber left us stranded. We now use them exclusively and you will too! It is easy to get an appointment, their technicians are professional, friendly and explain the issues in an understandable way. Their prices are great and they don’t upsell or pressure you into anything. Do yourself a favor and call Downey first!!” - Michelle Deziel
“Our water heater went out on the weekend. Downey plumbing was so responsive and the bid came in very reasonable. The tech came out same day and replaced our water heater with very little down time. The job was exactly as quoted. I really appreciated the professionalism of the tech. Thank you Downey plumbing for getting us back up and running, because cold showers are no fun!” - Christine Rankin

ZIP CODES WE SERVE

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Areas we serve

562-502-8911