No heat or no cool? Check these first

No heat

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1. Thermostat on Heat, set a few degrees upSet it to Heat and about 5° above the room. If the screen is blank, put in fresh batteries.
2. Furnace switch and breaker onMost furnaces have a switch on or near them that looks like a light switch. Make sure it's on, and that the furnace breaker hasn't tripped.
3. Clear snow off the vent pipes outsideNewer furnaces vent through two white plastic pipes on an outside wall or the roof. After a big Colorado snow, drifts or ice can block them and shut the furnace off.
4. Swap a clogged filterIf you can't see light through the filter, a furnace can overheat and shut itself off. A fresh one costs a few dollars.
5. Close the furnace door all the wayThe front panel has a safety switch. If it's even a little loose, the furnace won't run.
6. Give it five minutesAfter you change something, the furnace runs a safety check before it lights. Wait five minutes before trying anything else.

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1. Thermostat on Cool, fan on AutoSet it to Cool and a few degrees below the room. If the screen is blank, put in fresh batteries.
2. Both breakers onCentral AC usually has two: one for the furnace or air handler inside, and one for the outdoor unit. Check the shutoff box next to the outdoor unit too.
3. Rinse cottonwood fluff off the outdoor unitIn early summer, cottonwood fluff mats onto the fins and chokes the unit. Turn the power off at the shutoff box, then rinse gently from the inside out with a garden hose.
4. Swap a clogged filterA dirty filter starves the system of air and can freeze the coil.
5. Ice on the lines? Let it thawIf the copper lines or the indoor coil are frosted, turn cooling off and the fan to On for 2 to 3 hours. Then call: ice means something else is wrong.
6. Check for water in the drain panIf the pan under the indoor coil is full, a float switch may have shut the AC off to stop a leak. That's a call, not a fix-it-yourself.