Commercial HVAC Repair & Emergency Service in Chatham-Kent
Emergency Commercial HVAC Repair Services
Postma provides 24/7 emergency commercial HVAC and refrigeration repair across Chatham-Kent, Sarnia-Lambton and Windsor-Essex. Rooftop units, boilers, make-up air, refrigeration and controls — diagnosed properly, quoted before work starts, and documented afterward.
Equipment down right now? Call our commercial line — 24 hours a day, weekends and holidays included.
519-354-9491
What to Check Before You Call
Some no-heat and no-cool calls turn out to be something a building manager can resolve in two minutes. We would rather you check these first than pay for a service call to find them.
| Check | Why It Matters |
|---|---|
| Thermostat and schedule | Confirm the unit is calling and the building is not sitting in unoccupied or setback mode. Schedules drift after a power outage, a time change, or someone changing a setpoint on a Friday afternoon. |
| Breakers and disconnects | Check the electrical panel and, where you can do so safely, the disconnect switch at the unit itself. Rooftop disconnects routinely get switched off during roof work and forget to be switched back on. |
| Filters | A badly clogged filter restricts airflow enough to trip a high-limit switch on heating or freeze a coil on cooling. It is one of the most common causes of a unit that runs, then shuts itself down. A quick check of the filter to see if it is need of replacement can help make the problem go away quickly. If it’s dirty, replace the filter, reset and see if the problem persists. |
| Condensate pan and drain | A blocked drain fills the pan and trips the float safety switch, which shuts the unit off deliberately to prevent water damage. The unit is not broken – it is protecting the building. |
| Gas supply and other units | If more than one piece of equipment is down at once, the problem is usually upstream – building gas supply, a shared breaker, or a controls or network fault rather than the equipment itself. Tell us that when you call; it changes what we bring and how we go about our diagnosis of the problem. |
If none of that resolves it, call us. Do not open electrical panels, reset a tripped safety more than once, or attempt gas-side work — those are the failures that turn an expensive repair into a dangerous one.
Common Commercial HVAC Failures
What the symptom usually indicates. This is diagnostic direction, not a diagnosis — the same symptom can have several causes, which is exactly why we test rather than guess.
| Symptom | Usual Causes |
|---|---|
| Fan runs but no cooling | Low refrigerant charge from a leak, failed compressor or contactor, a dirty condenser coil driving head pressure up, or a tripped high-pressure safety. |
| No heat on a gas unit | Ignition or flame sensor failure, gas valve, a high-limit tripped by restricted airflow, or a lockout from a cracked heat exchanger. The last one is a safety issue and the unit stays down until it is confirmed. |
| Unit short cycles | Restricted airflow, low charge, a failing thermostat or sensor, an oversized unit, or a control board fault. Short cycling wears compressors faster than almost anything else, so it is worth chasing early. |
| Water in the building | Blocked condensate drain, a rusted-through drain pan, or a frozen evaporator coil thawing. Ceiling stains under a rooftop unit are almost always one of these three. |
| Breaker trips repeatedly | A shorted compressor or motor, a failed capacitor, or a loose connection creating resistance and heat. Repeatedly resetting a breaker that keeps tripping is a fire risk, not a workaround. |
| Walk-in cooler warming up | Defrost cycle failure, an iced evaporator, failed door gaskets or sweeps, a dirty condenser, or low charge. Product loss makes this the fastest-clock call we take. |
| Hot and cold spots | Failed zone dampers or actuators, an economizer stuck open or closed, air balance lost after a renovation, or controls programmed against how the space is actually used now. |
| New or worsening noise | Bearing wear, a slipping or frayed belt, loose panels and fasteners, or compressor slugging. Noise is usually the cheapest stage of a failure to catch, so it is worth a call before it stops being noise. |
What Happens When You Call
|
Step 01
The Call We ask what the equipment is, where it is, what it is doing, and how urgent it is. Knowing this helps us determine which technician to send, which parts they should grab to help avoid a follow-up call and makes the diagnostic process more efficient so we can get the system up and running faster. |
Step 02
Dispatch Maintenance agreement customers receive priority dispatch. If we already maintain the building, the technician arrives knowing the unit, its age and what was flagged at the last inspection. |
Step 03
Diagnosis and Quote We find the root cause rather than the first thing that looks wrong, then quote the repair before work starts. If it is a repair-or-replace decision, you get both numbers. |
Step 04
Repair and Report The work is completed and documented – what failed, why, what was done, and what to watch. That report goes into the equipment history so the next call starts with context. |
Repeat failures are a different problem. If the same unit has needed three calls in two years, the issue is usually not the last part that failed. We will tell you when the honest answer is replacement rather than another repair – see commercial HVAC replacement and installation, or our commercial HVAC preventative maintenance program for equipment.
Commercial HVAC Repair FAQ
Do you offer 24/7 emergency commercial service?
Yes. Commercial HVAC, refrigeration and plumbing emergencies are covered 24 hours a day, including weekends and holidays, at 519-354-9491. Maintenance agreement customers receive priority dispatch and reduced after-hours rates.
Do you repair equipment you did not install?
Yes. We service all major commercial brands regardless of who installed the equipment. If you are not currently a customer we will still document the unit and leave you with a report you can use.
Will I know the cost before work starts?
Yes. We diagnose first, then quote the repair for approval before proceeding. On equipment near end of life we quote the repair and the replacement together so you are choosing against a full picture rather than approving a repair blind.
How quickly can you get parts for commercial equipment?
Our service vehicles carry common rooftop unit, boiler, refrigeration and control components, so a large share of calls are resolved on the first visit. Less common parts and components, OEM-required parts, and parts for older units (15+ years old) can carry lead times of days to several weeks — if that applies, we will tell you immediately and discuss temporary heating or cooling options to keep your business operating. We hold strong relationships with all major brands and distributors to ensure priority service for parts.
Can you provide temporary heating or cooling while we wait?
Yes, where a permanent repair will take time and the space cannot go without. This comes up most often on long-lead parts and on buildings that cannot close, such as long-term care facilities, manufacturing plants and government buildings.
Is it cheaper to have a maintenance agreement?
For most buildings, yes — but the saving is not on the repair itself. It comes from catching failures earlier and at a cheaper stage, avoiding after-hours calls, and keeping the manufacturer warranty valid. Agreement customers also receive priority dispatch and reduced after-hours rates. See preventative maintenance.
Do you work on plumbing and electrical emergencies too?
Yes. We cover commercial plumbing and commercial electrical services.
See all commercial HVAC services, or our preventative HVAC maintenance program to avoid future emergency HVAC repairs on your commercial equipment.
Equipment down? Call 519-354-9491. We offer commercial HVAC repair services across Chatham-Kent, Sarnia-Lambton and Windsor-Essex, with same-day service typically available.