Houston doesn't get months of winter, but when a cold snap shows up it shows up fast. The temperature can drop 30 degrees in a few hours. A heater that hasn't run since February suddenly has to work at 9 p.m., and a surprising number of these “emergencies” turn out to be a thermostat, a breaker or a dirty filter.
Go through this list before you decide the compressor is dead. If any of the danger signs further down show up, stop and call us.
1. Check the thermostat first
A big share of no-heat calls aren't HVAC failures at all, so rule out the easy stuff before you panic.
- Make sure it's actually set to HEAT and not COOL
- Set the target 3–5 degrees above room temperature
- Check that the system didn't get switched OFF after a power blink
- Put in fresh batteries if it uses them
- On a smart thermostat, make sure it didn't fall back to a schedule that set it to “away”
2. Breakers, filter and the outdoor unit
Indoor and outdoor units often have separate breakers, and a summer lightning blink can leave one of them off. Reset a tripped breaker once, not over and over. Check the filter too. A packed one can make a heat pump seem dead and can overheat the electric strips. Out back, pull any leaves or plastic bags off the unit. If the heat pump is a solid block of ice, it needs a technician. Spraying it with a hose in a freeze won't help.
When to call us right away
Call if the system only blows cold air, won't start, or smells electrical or like something's melting. Same goes for a heat pump that's iced solid, a furnace that cycles on and then right back off, a breaker that trips more than once, or any smell of sulfur. If you think there's a gas leak, get out of the house first, then call the utility, then us. You can read more about our heating and furnace repair calls.
Staying safe until we get there
Close the doors to rooms you aren't using, but leave bathroom doors cracked so the pipes aren't sitting in a closed-off cold room. Don't use the oven as a heater. A space heater needs a proper circuit and plenty of room away from bedding. Around here it's the pipes on exterior walls that tend to fail. Letting a faucet drip slowly can help, but a frozen line is a job for a plumber, not an HVAC company.
Heading off the next one
Get a fall tune-up and put in a fresh filter. Have the heat strips checked before the first front. Keep the outdoor unit clear, leave the vents open, and test the heat in November. Not during an ice storm. Heaters around here mostly fail because they sit. Regular maintenance is the one thing that reliably keeps you out of the 2 a.m. scramble.
From all of us at Velocity Air A/C & Heating