Troubleshooting Guides
Identify symptoms, understand possible causes and know when to call a professional.
A burner in lockout, a boiler that won't start, an error code on a rooftop unit — these situations demand a swift and methodical diagnosis. Our troubleshooting guides help you identify common symptoms, understand likely causes and assess the urgency level before calling a technician.
Each guide indicates a risk level to help you prioritize: some failures can tolerate a delay, while others require immediate intervention. These resources do not replace a professional diagnosis, but they allow you to communicate effectively with your service provider and speed up resolution.
Abnormal Noise on a Circulation Pump — Careful Diagnostics
Grinding, cavitation or hammering on a commercial building pump: initial assessment without disassembly and when to call a pro.
Commercial Air Conditioner Won't Start — Causes and Checks
Commercial AC or rooftop unit that won't start: frequent causes, risk-free checks and when to call a commercial HVAC technician.
Blocked Boiler Vent or Air Intake — Safety Lockout
Snow, ice or debris blocking a gas boiler's vent or air intake: repeated lockouts, carbon monoxide risk, safe checks and when to call a professional.
Condensing Boiler Lockout — Blocked or Frozen Condensate
A condensing boiler locking out because of blocked or frozen condensate: symptoms, what to check and when to call a professional for a diagnosis.
Boiler Losing Pressure — Causes and Diagnosis
A commercial boiler that keeps losing pressure: common causes, what to check and when to call a professional for a proper diagnosis.
Boiler Water Leak — Quick Assessment and Emergency
Water leak near a commercial boiler: what to document, when to escalate. Water, electrical and gas risks — leave the diagnosis to a professional.
Boiler Won't Start — Diagnostics and Safety
Symptoms and guidance when a commercial boiler refuses to fire. Do not work on gas without proper qualification — call a professional.
Burner Lockout — Causes, Fault Reading and Safety
Understanding a gas burner lockout in industrial or commercial settings. Do not force restarts; call a combustion specialist.
Carbon Monoxide Alarm — What to Do in a Building
A CO detector goes off in a commercial building: emergency steps, likely combustion causes and what a safe return to service requires.
Frozen Coils on an AC or Rooftop Unit — Causes and Safe Steps
Frost or ice on a commercial AC evaporator: causes (airflow, refrigerant), risk-free steps and when to bring in a professional.
Gas Smell in the Mechanical Room — What to Do Now
Gas smell in a commercial boiler room: emergency steps, what you must never do and when to evacuate. Don't work on gas — call a professional.
Iced-Up Commercial Heat Pump — When Defrost Fails to Clear It
Persistent ice on a commercial heat pump: why the defrost cycle fails, risk-free steps and when to bring in a technician.
Low-Water Cutoff Trip — Steam Boiler Shut Down
A steam boiler tripping on low water: common causes, the dry-firing risk and what to do — and not do — before a technician arrives.
Refrigerant Leak: Symptoms and What to Do in Your Building
Recognizing a refrigerant leak on a commercial air-conditioning system: warning signs, risks, regulations and the right reflexes.
Rooftop (RTU) Not Cooling — Diagnostic Leads
A careful checklist for a rooftop unit with no cooling in a commercial setting. Non-invasive checks and guidance on when to call an HVAC technician.
Rooftop (RTU) Not Heating — Causes and Diagnosis
Rooftop unit with no heat in a commercial building: common causes, safe checks and when to call a commercial HVAC technician.
Boiler Short Cycling — Causes and Diagnostics
A boiler that starts and stops too often (short cycling): common causes, safe checks and when to call a professional for a commercial system.
Water Hammer in a Steam System — Causes and Risks
Violent banging in steam piping: common causes, what it puts at risk and when to bring in a professional for a proper diagnosis.
Unstable Burner Flame — Causes and Safety
A burner flame that flickers, pulses or lifts off: common causes, safe checks and warning signs, including the risk of carbon monoxide.
24/7 Emergency — Fast Response Across Grand Montréal
Boiler failure, air conditioning down in a heat wave, or equipment breakdown? Our technicians respond quickly, summer and winter.
450-473-0909