Orlando's airport averages only a night or two below freezing in a typical year. Some winters have none and some have several, and outlying areas get them more often than downtown. So when a freeze warning goes out, people prepare as if a hurricane is coming. Plants get sheets, pipes get wrapped, and every year a few heat pumps get a tarp tied over them.
Please do not do that last one.
Do not cover the heat pump
On a freeze night your heat pump is not sitting idle. It is the thing heating your house. It works by pulling large volumes of outdoor air across its coil, and a tarp or blanket blocks that air. The coil ices over, the fan motor strains against the cover, and the system falls back to running the expensive strips. Plastic sheeting also traps moisture against the cabinet long after the cold has passed.
Heat pumps are built for far colder weather than Orlando gets. The same models we install here are sold in places where 20-degree nights are routine. A Central Florida freeze is well within what they are designed for.
If you have a straight-cool AC (no heat pump), the outdoor unit is off all winter anyway, and a freeze will not hurt it. It does not need a cover either. If you put one on, cover only the top with something breathable, and take it off before the system runs again. A warm, humid 80-degree day in January is entirely possible here.
Four things worth doing before dark
- 1Turn off or redirect sprinklers near the outdoor unit. Some people run irrigation overnight to protect plants from frost. Water spraying on a heat pump in freezing air builds a shell of ice that defrost cannot clear.
- 2Check that no gutter or roof edge drips onto it. Same problem, slower.
- 3Set a steady temperature, around 68°F, and leave it. Do not let the house cool off overnight and then turn it up to 72 at 6am. That recovery runs on the electric strips at the coldest hour of the night, when the heat pump is least efficient and the whole region is turning its heat up at once. It costs you, and it loads the grid at its worst moment.
- 4Test the heat this afternoon, not at 10pm. If something is wrong, you want to find it while companies still have openings in the day. Our winter checklist covers the quick version.
Two things that cost people money
- Switching to Emergency Heat "for extra heat." It is not extra. It turns off the heat pump and runs the strips alone, at roughly three times the cost per unit of heat, with less total output. Em Heat is for a broken outdoor unit, nothing else. More in aux heat vs emergency heat.
- Attacking morning frost. A frosted outdoor unit at sunrise is normal, and the defrost cycle will clear it. Do not chip it, and do not pour boiling water on it. The difference between normal frost and a real problem is in ice on your heat pump.
If the heat stops in the middle of the night
- 1Check the breakers, including the separate one many Florida air handlers have for the heat strips. Reset a tripped breaker once. If it trips again, leave it off.
- 2If the outdoor unit is iced solid or not running, switch to Em Heat to keep the house warm on the strips alone.
- 3If you have no heat at all, close doors to unused rooms and keep everyone in one part of the house.
- 4Call. We answer around the clock, and there is no surcharge for the night it happens to be cold.
The rest of a freeze checklist, covering hoses, backflow preventers, pool equipment and plants, belongs to your plumber and your landscaper. This is the HVAC part. If the heat is not right before the next cold front, book a diagnostic on our heating repair page.
Written by
The Eco Air Orlando team — licensed Florida HVAC contractors, #CAC1814992. Everything here comes from work we actually do in Central Florida homes.