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🔥 Diagnosis & repair

Diagnostics, measurements and repair of HVAC-R refrigeration systems.

23 articles
HP
Diagnostic

Heat pump blowing cold air in heat mode: step-by-step troubleshooting

Heat pump blowing cold air in heat mode? Troubleshoot defrost, thermostat, reversing valve, airflow, auxiliary heat and the refrigerant circ...

2026-08-24 Read →
C
Diagnostic

Compressor humming and tripping overload: HVAC-R troubleshooting guide

Compressor hums without starting and trips overload? Diagnose voltage, capacitor, relay, overload, windings, pressures and locked rotor safe...

2026-08-24 Read →
âť„
Diagnostic

AC running but not cooling: step-by-step HVAC troubleshooting guide

AC running but not cooling? Field troubleshooting for thermostat settings, airflow, evaporator and condenser coils, refrigerant circuit and ...

2026-08-23 Read →
⚡
Diagnostic

HVAC 3-amp fuse keeps blowing: finding a 24V short without damaging the board

HVAC 3A or 5A fuse keeps blowing? Field method to isolate thermostat wiring, contactor coils, accessories, equipment wiring and the 24V tran...

2026-08-23 Read →
Ω
Diagnostic

Grounded compressor: winding resistance and HVAC electrical testing guide

How do you test a grounded compressor? HVAC-R guide to C-R-S terminals, winding resistance, insulation, overloads, voltage and start compone...

2026-08-21 Read →
TXV
Diagnostic

TXV troubleshooting: high superheat, low superheat and hunting guide

TXV underfeeding, overfeeding or hunting? HVAC-R guide to bulb mounting, equalization, charge, restrictions, sizing, subcooling and adjustme...

2026-08-21 Read →
A
Diagnostic

AC breaker keeps tripping: causes and safe HVAC troubleshooting guide

Why does an AC breaker keep tripping? A 2026 guide to overloads, shorts, capacitors, motors, compressors, wiring and safe HVAC measurements.

2026-08-20 Read →
HOT
Diagnostic

High compressor discharge temperature: HVAC-R causes and diagnosis guide

Compressor running hot? A guide to high discharge temperature, superheat, compression ratio, charge, condenser conditions, motor cooling and...

2026-08-20 Read →
24V
Diagnostic

Thermostat blank screen: no-power and 24V HVAC troubleshooting guide

Thermostat screen blank? A 2026 HVAC guide to batteries, breakers, switches, doors, drains, float switches, fuses, transformers and C-wire p...

2026-08-15 Read →
P/T
Diagnostic

Low suction and high head pressure: HVAC-R refrigeration diagnosis guide

Low suction and high head pressure? A field guide to compression ratio, airflow, condenser conditions, restrictions, metering devices, charg...

2026-08-15 Read →
µF
Diagnostic

Bad AC capacitor: symptoms, testing and HVAC troubleshooting guide

AC humming, hard starting or shutting down? A field guide to identifying and testing a bad HVAC capacitor without guessing or replacing part...

2026-08-13 Read →
ICE
Diagnostic

Frozen evaporator coil: causes, measurements and HVAC troubleshooting guide

Why does an evaporator coil freeze? A field guide to airflow, filters, blower operation, charge, restrictions, saturation temperature and su...

2026-08-13 Read →
H2O
Diagnostic

Mini split leaking water inside: drain, ice and installation troubleshooting guide

Why is a mini split leaking water inside? A 2026 field guide to clogged drains, slope, drain pans, pumps, filters, frozen coils and installa...

2026-08-11 Read →
24V
Diagnostic

HVAC contactor not pulling in: step-by-step 24V troubleshooting guide

AC contactor not pulling in? A 2026 guide to troubleshooting the Y call, 24V circuit, transformer, fuse, safeties, coil, contacts and load s...

2026-08-11 Read →
WIC
Diagnostic

Walk-in cooler not cooling: 2026 commercial refrigeration troubleshooting guide

Walk-in cooler running warm? Use this 2026 field checklist for airflow, defrost, evaporator, condenser, electrical readings, pressures and r...

2026-08-10 Read →
SC
Diagnostic

HVAC compressor short cycling: causes, tests and 2026 troubleshooting guide

HVAC-R compressor short cycling? Diagnose controls, pressure switches, airflow, condenser, charge, voltage, safeties and equipment sizing.

2026-08-10 Read →
HP
Diagnostic

Heat pump not cooling: 2026 HVAC troubleshooting checklist

Heat pump not cooling? Use this 2026 field checklist for thermostat, airflow, coils, defrost, electrical readings, pressures and refrigerant...

2026-08-08 Read →
IA
Diagnostic

AI HVAC-R diagnostic software: a field guide for technicians

A practical guide to AI-assisted HVAC-R diagnostics: symptoms, measurements, nameplates, P/T charts and service reports in one field workflo...

2026-08-03 Read →
🌡️
Diagnostic

Superheat and subcooling: the field diagnostic method in Canada

A clear field method to measure superheat and subcooling, read the P/T chart, verify the charge and diagnose a refrigeration or air conditio...

2026-06-18 Read →
AI
Diagnostic

HVAC-R AI assistant and field measurements: better diagnostics across Canada

Canada-wide guide to using an HVAC-R AI assistant with real field measurements: LP/HP, P/T, superheat, subcooling, delta T, photos and servi...

2026-06-17 Read →
🤖
Diagnostic

AI assistant for refrigeration technicians in Quebec: faster field diagnostics, measurements and reports

How a specialized HVAC-R AI assistant helps Quebec refrigeration technicians in the field: technical questions, diagnostic paths, P/T, measu...

2026-06-08 Read →
🔥
Diagnostic

Superheat and subcooling: practical guide for HVAC-R techs

How to measure and interpret superheat and subcooling on a refrigeration system. Normal values, diagnostics, and troubleshooting.

2026-04-12 Read →
⚠️
Diagnostic

5 signs a refrigeration compressor is about to fail

How to detect early warning signs of a failing compressor: abnormal noises, overheating, high pressure, excessive current draw.

2026-04-12 Read →

Explore other categories

đź“‹ Compliance
CSA B52 refrigerant log, documents and compliance for refrigeration techs in Canada.
⚖️ Regulation
Halocarbons Regulation, CSA B52 standard and legal obligations for refrigeration techs.
đź”§ Field & technique
Field best practices, preventive maintenance and advanced HVAC-R techniques.
🚀 Business & entrepreneurship
Starting your business, billing with province-specific taxes and managing your refrigerati...
đź”§ Tools & comparisons
Technical tools, software comparisons and quick references for refrigeration techs.
đź’° Subsidies
Hydro-Québec, Logis-Vert and other financial assistance programs for heat pumps and HVAC.
đź’Ľ Career
CCQ pay scales, hourly rates and career opportunities in refrigeration in Quebec.
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