HeatingCodesWinter heating guides
Each guide cites manufacturers, the U.S. Department of Energy, ENERGY STAR or state health agencies, and tells you where a homeowner should stop and call a licensed technician.
How to read your furnace blinking light code
How furnace LED flash codes work: where to find the light, how to count flashes, why Carrier, Trane and Goodman differ, and a safe first-response checklist.
GuideFurnace turns on and off every few minutes (short cycling): causes and safe checks
Why a furnace short cycles, based on manufacturer documents: limit switches, flame sensing and pressure switches. Safe homeowner checks and when to call a technician.
GuideFurnace igniter glows but the burners never light
If a furnace igniter glows orange but the burners do not light, here is what manufacturer documents list as causes, what is safe to check and what needs a technician.
GuideFurnace after a winter power outage: restart steps and generator safety
How to restart a furnace after a power outage, why a furnace may show a code afterward, and the Washington State Department of Health generator and carbon monoxide rules.
GuideTankless water heater no hot water in cold weather: what to check
Tankless water heater not heating in freezing weather? Manufacturer guidance from Navien and Rinnai on freeze protection, frozen condensate lines, vent blockage and error codes.
GuideHeat pump in defrost mode: steam, noise and when to worry
Why a heat pump steams and blows cooler air in winter. How long defrost normally lasts, how often it runs, and signs of a real problem, based on Lennox guidance.
GuideThermostat screen blank or not powering up: what to check
A blank thermostat screen can be a breaker, a power switch, a closed furnace door or a missing C wire. Steps from Honeywell Home support, with safe limits for homeowners.
GuideBest thermostat settings for winter savings (and the heat pump exception)
DOE says turning your thermostat back 7 to 10 degrees F for 8 hours a day can save up to 10% a year. Why, how to set a schedule, and why heat pumps are different.
GuideShould you repair or replace your furnace? Rules of thumb from ENERGY STAR and the DOE
ENERGY STAR says consider replacement if a furnace is over 15 years old. The DOE flowchart adds a repair-cost test. Use these rules plus our calculator before you decide.
GuideCarbon monoxide and winter heating safety: a checklist from Washington State DOH
Carbon monoxide can build up quickly when fuel is burned. Symptoms, prevention rules and generator guidance from the Washington State Department of Health.