Kitchen too hot?
Five questions, one plain-English answer about what's wrong.
Weak airflow, warm dining rooms, short cycling, and rooftop units that ice over each trace to a different failure inside your HVAC system. Answer five quick questions about the symptoms and we'll tell you whether it's a dirty coil, a refrigerant problem, a failing motor, or just neglected maintenance, plus whether you need a tune-up, a repair call, or same-day dispatch.
Kitchen and dining room failures are different problems
A commercial HVAC system serves two distinct environments with different stakes. When the kitchen stops cooling, it is a staff safety issue and a potential food safety issue, ambient heat stresses refrigeration equipment and puts crew at risk during long service periods. When the dining room stops cooling, it is a revenue and reputation issue, guests leave, reviews suffer, and table turns shorten.
Both matter. But they fail for different reasons and they require different urgency responses. The diagnostic above takes that into account.
The four things that go wrong with commercial restaurant HVAC
Commercial HVAC failures in a restaurant cluster around four mechanical and operational causes. Each one looks slightly different at the unit, and each one has a different urgency response. Knowing which one you have before you call avoids paying for the wrong service.
Why Southern California summers stress restaurant HVAC harder than anywhere else
A commercial kitchen generates between 60,000 and 100,000 BTUs of heat per hour during service from cooking equipment alone. The HVAC system's job is to fight that heat load while also fighting outdoor ambient temperatures. When outdoor temperatures climb above 95°F, common in Los Angeles County from June through October, the system is working against a thermal load on both sides simultaneously.
The condenser, which dissipates heat from the refrigerant to the outdoor air, becomes dramatically less efficient as outdoor temperatures rise. A system that performs adequately in mild weather can fail to maintain setpoint temperatures on a hot afternoon in Burbank or the San Fernando Valley, where summer temperatures regularly exceed 100°F.
This is why deferred maintenance compounds so quickly in Southern California. A system with partially fouled coils that manages fine in March will fail in July. The maintenance visit that gets postponed in spring is the emergency call that happens in August.
How often should a restaurant service its HVAC system
Quarterly is the standard for commercial restaurant HVAC, and the minimum for a kitchen environment. A high-volume kitchen with heavy fry activity, a rooftop unit exposed to grease exhaust from the hood, or a building in a high-dust area like the eastern San Gabriel Valley should consider every two months.
What a quarterly service covers: condenser coil cleaning, evaporator coil inspection, internal filter replacement (included in every Boh HVAC visit), fan motor and belt inspection, refrigerant pressure check, electrical connection inspection, airflow test, and a full system cycle verification before the technician leaves.
The filter replacement is often treated as the whole job. It is not. Filters protect the system, they do not clean it. Condenser coils that are never cleaned accumulate a layer of grease and dust that no filter change addresses. A quarterly visit that includes coil cleaning is a different service from a filter swap, and restaurants that conflate the two consistently end up with early compressor failures.
Common questions
My HVAC is running but not cooling. What does that mean?
A system that runs continuously without reaching setpoint temperature has one of three problems: dirty condenser coils blocking heat dissipation, a refrigerant leak reducing system pressure, or a compressor that is overworking and starting to fail. All three produce the same symptom. The diagnostic tool above helps narrow it down based on your specific situation.
Why is one part of my dining room hot while the rest is fine?
Uneven temperatures almost always point to a distribution problem rather than a system failure. The most common causes are a damper that has drifted or failed in a partially closed position, a disconnected or leaking duct joint, or a supply register that has been blocked. Check that all vents are open and unobstructed first. If clearing vents does not resolve it within a day, a technician needs to inspect the ductwork.
My HVAC was just serviced but it still isn't cooling. Why?
A recently serviced system that immediately loses cooling usually has a problem that a maintenance visit could not address, typically a refrigerant leak that developed after the service date, a compressor that is beginning to fail, or a refrigerant pressure that was not checked during the maintenance visit. A repair diagnosis visit is the next step.
How do I know if my condenser coils need cleaning?
If you can access the rooftop unit, look at the condenser coil fins. If they are visibly coated in dust, grease, or debris, or if you cannot see through the fins at all, they need cleaning. A less obvious sign is the unit running significantly longer cycles than it used to. If your last maintenance visit was more than 6 months ago in a kitchen environment, the coils almost certainly need cleaning regardless of how they look.
Is it worth repairing an HVAC unit that is more than 10 years old?
Depends on what the repair is. A belt replacement or fan motor repair on a 12-year-old unit is usually worth doing. A compressor replacement on a unit approaching the end of its design life often is not, the compressor cost approaches the cost of a new unit, and the rest of the system is aging alongside it. A Boh technician will assess on-site and give you a repair vs. replace recommendation with numbers before any work begins.
What should I do right now if my kitchen HVAC has stopped working?
First, move any temperature-sensitive product to verified cold storage if ambient kitchen temperatures are rising toward the danger zone. Second, increase natural ventilation, open back doors, use fans, to reduce heat exposure for your crew. Third, check the circuit breaker for the rooftop unit before calling for service; a tripped breaker is a common and easily resolved cause. If the breaker is fine and the unit is not running, dispatch a technician today.