Furnace/Heating Repairs
From ignition failures to heat exchanger issues, we diagnose and repair all furnace and heating system problems to keep your home warm and comfortable.
Professional Diagnostic Reference — Not a DIY Guide
This checklist reflects the diagnostic procedure our trained HVAC technicians follow during a furnace service call, along with additional safety protocols not listed here. It is published for informational purposes only so homeowners can better understand what goes into a professional furnace diagnosis.
Many steps involve live electrical testing, gas components, and high-temperature parts that can cause serious injury, fire, or carbon monoxide exposure if handled incorrectly. Do not attempt technician-level steps unless you are a qualified HVAC professional.
Furnace Diagnostic Checklist
When your furnace won't heat, the problem can usually be traced by following the sequence of operation — the exact order your furnace goes through every time it fires up. This interactive checklist walks you through each component in order, from the thermostat signal all the way through the blower motor and heat exchanger.
Each check is marked as either homeowner-safe or technician-required. Homeowner-safe items are basic visual or setting checks you can do yourself. Technician items involve electrical testing, gas components, or disassembly that should only be performed by a qualified HVAC professional.
Stop Guessing. Start Monitoring. (Free monitoring for six months)
Why wait for a complete system failure to find out something is wrong? With our Smart Monitoring system installed, you—and our technicians—get a real-time look into your furnace's health. Instead of guessing why the sequence of operation stopped, we can pinpoint exactly which sensor is failing or struggling before the heat even goes out. It's the difference between a proactive fix and an emergency repair.
How the Furnace Sequence of Operation Works
The thermostat initiates the heating cycle by sending a call for heat to the control board. Start here to rule out the simplest issues first.
Safety reminder: Always turn off power to the furnace before inspecting internal components. If you smell gas, leave the area immediately and call your gas utility. Steps marked Technician involve electrical testing, gas components, or disassembly — do not attempt these unless you are a qualified HVAC professional.
Need a Professional Diagnosis?
Our certified HVAC technicians carry common furnace parts on every truck for fast, same-visit repairs. We service all major furnace brands.