Cooling Problems
What to check when the air conditioner runs but the house stays warm.
Explore topic →Old-school experience. Modern solutions.
Real answers for the systems that keep your home comfortable.
Clear, field-tested HVAC and home-system guidance for homeowners and working technicians—without the sales pitch.
Field Tested
Honest guidance built on real service experience.
PracticalDependableClear
30+ YearsTrade Experience
Veteran OwnedService and Integrity
Field TestedPractical Information
No Sales PitchStraight Answers
Homeowner Help
Understand what is happening before you make the call.
Safe checks, plain explanations, and honest guidance about when a problem requires a qualified professional.
Heating Problems
Plain-language help for furnaces, heat pumps, and electric heat.
Explore topic →Electrical Basics
Breakers, disconnects, thermostats, and safe checks before calling for service.
Explore topic →Home Systems
Practical guidance for generators, plumbing, airflow, and manufactured homes.
Explore topic →Safety first: This site helps you understand your equipment. It does not encourage homeowners to work on energized electrical systems, pressurized refrigerant circuits, or fuel-burning equipment.
The Technician's Bench
Useful information for the person holding the tools.
Troubleshooting routines, equipment data, and service practices written to help technicians find answers in the field.
Open the Equipment Library✓Diagnostic procedures and fault codes
✓Airflow, static pressure, and ductwork
✓Refrigerant charging and system performance
✓Wiring diagrams and control troubleshooting
✓Equipment specifications and service manuals
✓Field-tested installation practices
From the Bench
Featured guidance
Why Your Air Conditioner Runs but Does Not Cool
A safe, step-by-step look at airflow, thermostat settings, outdoor equipment, and when to stop and call a technician.
Read guide →Start With Airflow: A Better Diagnostic Routine
Why airflow belongs near the beginning of every service call—and the measurements that prevent misdiagnosis.
Read guide →Understanding HVAC Fault Codes
How to use a fault code as a starting point without treating it as a final diagnosis.
Read guide →
Featured HVAC Technical Manual
HVAC Technician Troubleshooting Handbook
A practical field handbook covering electrical diagnostics, controls, motors, airflow, refrigeration, heating, heat pumps, and systematic troubleshooting. Each subject explains what to check, why it matters, what normal readings look like, and what to do next.
Equipment Library
Manuals, specifications, codes, and field notes.
This reference library will grow with manufacturer information, equipment data, diagnostic codes, and additional field guides.
DC
About the Service Bench
Experience worth passing down.
The Service Bench was created by Dale Cotten, a veteran and tradesman with more than three decades of experience in HVAC and electrical service. It is a place to share practical knowledge with homeowners and the next generation of technicians.
The goal is simple: explain how systems work, help people make better decisions, and preserve the field knowledge that is too often learned the hard way.
Ask Dale
Have an HVAC or home-system question?
Send the model number, a description of the problem, and any fault code you see. Never include passwords, payment information, or other private information.