Before You Call: Quick Mini Split Fixes
A few simple checks solve many ductless mini split problems. Try the ones that fit, and if your system still isn’t right, send us a repair request.
Burning smell, sparks or smoke? Turn off the breaker for the unit now and call (304) 246-3080.
Clean the filters
Clogged filters cause weak airflow, icing and shutoffs. Check and clean them regularly. Construction dust clogs filters fast, so check them often during any remodeling. Keep furniture and decorations clear of the heads so air can move.
Check the mode
Set the remote to Heat or Cool. In Dry or Fan mode the unit won’t heat or cool the way you expect. Use Auto only when one unit is running by itself (see “--” on the display).
Check the remote
Put fresh batteries in the remote, then check that the setpoint (the temperature you set) is where you want it.
“--” on the display
“--” isn’t an error code. It means two units on the same outdoor unit are asking for different modes: one is calling for heat and one for cooling. The unit showing “--” is the one set to cool (or that Auto switched to cooling).
To fix it: set the other unit to Cool, or set the “--” unit to Heat.
Tip: avoid Auto mode when more than one unit is running. Save Auto for times you’re only using one unit, so this mode conflict doesn’t happen.
Upstairs warm, downstairs cool
That’s heat rising. Heads downstairs warm the upstairs too, so an upstairs head can keep blowing air even when the room already feels warm. In Heat or Cool mode the fan keeps running on purpose. Try one of these:
- Turn on Follow Me (on some remotes it’s called I Feel) and leave the remote in the room where you sit, so the unit reads the temperature there instead of up near the ceiling and the fan doesn’t keep running.
- Or just turn the upstairs head off and let the heat from downstairs rise.
Follow Me needs fresh batteries in the remote. Set each head separately for its own room. Floor not warm enough? See fan speed.
Reset the breaker once
If the unit is dead, check the breaker and reset it one time only. If it trips again, leave it off and don’t keep resetting it. Send us a repair request or call. Lights dimming or flickering power can mean low or unsteady power from the utility, which is a power-company issue, not the unit.
Voltage monitor lights
Most systems we install have a voltage monitor, a small box mounted outside near the outdoor unit that protects your system from bad power. After a power blip or outage, it waits about 3 minutes before turning power back on, and then your mini split takes about 10 more minutes to start. That’s about 13 minutes in all, so wait about 15 minutes before calling.
- Two steady green lights: everything’s good.
- Two blinking green lights: it’s in its waiting period after a power event. Wait, and the unit will come back on by itself.
- Anything else: there’s an issue. What the lights mean is printed on the front of the voltage monitor. Tell us what you see.
Low or unsteady power from the utility is a power-company issue; the voltage monitor is doing its job by shutting things off.
Snow around the outdoor unit
Gently clear snow away from the outdoor unit so air can flow. Never chip ice off the coil. If ice or snow keeps falling on it from the roof, let us know.
Water dripping from a head
Turn the unit off at the remote, and protect the floor and any electronics below it. If you have a condensate pump (a small box near or below the head), check that it’s plugged in and running and that its drain tube isn’t kinked.
Wi-Fi or app shows “offline”
App “offline” problems are usually the router or internet provider, not the unit. Check that the unit still heats or cools from the remote.
Burning smell, sparks or smoke
Turn off the breaker for the unit now and call (304) 246-3080. Don’t turn it back on.
Normal things your mini split does
These sights and sounds are part of how a ductless mini split works. You don’t need a service call for them.
Defrost (“DF” on the display)
In cold, damp weather, frost builds up on the outdoor unit, so every so often in winter the system runs a short defrost, usually a few minutes. It can happen more often in freezing, humid weather. During defrost the unit pauses heating, the indoor fan may slow or stop, and the display may show “DF” or a defrost light. You may also see steam rising off the outdoor unit as the frost melts. That’s normal, and heat comes back on its own.
Call us if the outdoor unit stays packed with ice or heat never comes back.
A whoosh from outside in winter
At the start and end of defrost you may hear a loud whoosh from the outdoor unit. That’s the reversing valve switching the system’s direction, and it’s normal.
Grinding, banging that keeps going, a burning smell or real smoke isn’t normal. Turn the unit off and call us.
Gurgling, creaking or cracking indoors
Gurgling or a “water flowing” sound is usually refrigerant moving through the lines, or water in the drain. Creaking or cracking comes from parts expanding and contracting as the unit heats and cools, and it’s often loudest during or right after defrost. Both are normal.
Call us if a noise is constant, grinding, rattling, squealing or loud buzzing, gets louder over time, or comes with dripping water or an error code.
A few droplets on the louver
When the house is very humid, cold air leaving the unit can make a few droplets form on the louver (the moving flap), the way a cold glass sweats. That’s usually condensation, not a drain backup. Keeping doors and windows closed usually helps. Keep an eye on it.
It’s a real leak if water drips steadily, runs down the wall or makes puddles. Turn the unit off at the remote, protect the floor, and contact us right away at (304) 246-3080.
Doors open or closed?
Each head heats or cools the space it can reach. Keep doors closed to rooms you aren’t heating or cooling. If one head is meant to heat or cool several areas, keep those doors open. A room with no head of its own will usually stay cold with the door shut.
Fan speed
Keep the fan speed on Auto most of the time. (That’s the fan setting on the remote, not Auto mode.)
- Floor not warm enough in Heat mode? Briefly use Turbo or the highest fan speed to push the warm air down to the floor, only while you’re in that room, then go back to Auto fan speed. Running the fan on high wears the unit out, so keep it to a minimum.
- In Cool mode, don’t turn the fan up to high. It can leave the room humid. If you change the fan speed in Cool mode, set it to the lowest speed. That removes the most moisture from the air.
Cool air in heat mode
Air can feel cool at the end of a heat cycle, when the room reaches your set temperature and the fan keeps moving room-temperature air. It can also feel cool during defrost. Both are normal. Check that the remote is on Heat and the setpoint is above the room temperature.
Still not working?
Tell us what’s going on and we’ll take it from there. Mini Split Doctors® services ductless mini splits Mini Splits USA® installed, plus systems that came with a home you bought.