36 straight answers about furnaces, boilers, heat pumps, air conditioning and safety. Can’t find yours? Call HVAC Sioux City.
Calling HVAC Sioux City
How does calling HVAC Sioux City work?
You call, tell us what your heating or cooling system is doing and where you live in Sioux City, and we arrange for a licensed local technician to come out. There is no form to fill out first and nothing to sign before you talk to us.
Is it free to call?
Yes. Calling HVAC Sioux City is free. Anything to do with the repair itself, including what it involves, is something you go over directly with the technician before any work starts.
Who actually comes to my house?
A licensed heating and cooling technician who works in the Sioux City area. You can ask to see their license when they arrive. Our about page explains how HVAC Sioux City works in more detail.
What should I have ready when I call?
Your address, a short description of the problem, when it started, and anything you have already checked. Helpful extras: the type of system (furnace, boiler, heat pump, central air, mini split), the brand, and any blinking light pattern on the furnace control board.
Do I need to be home for the visit?
Someone over 18 should be there to let the technician in, show them the equipment and the thermostat, and approve any repair. Clear a path to the furnace or the outdoor unit, and put pets in another room.
Do you work outside Sioux City?
No. HVAC Sioux City is focused entirely on homes in Sioux City, Iowa.
Furnaces, boilers and heat pumps
Why is my furnace blowing cold air?
First check that the thermostat fan is on Auto rather than On, because On runs the blower even when the burners are off. If it is on Auto, the burners are probably not lighting or are shutting off early. Dirty flame sensors, failed igniters and tripped safety switches are the usual causes. See furnace repair.
What is that burning smell when the heat first comes on in fall?
Dust that settled on the burners and heat exchanger over summer burns off the first few times the furnace runs. A faint smell that fades within an hour is normal. A smell that lingers, gets stronger, or smells like hot plastic or wiring is not. Turn the furnace off and call.
How long should a furnace last?
Many gas furnaces run fifteen to twenty years or more with regular care, and some go longer. Age alone is not a reason to replace one. Condition is what matters, especially the heat exchanger, and a technician can give you an honest read on it.
Why is my high efficiency furnace dripping water?
High efficiency furnaces make water as part of how they work, and it drains through a trap and a hose, sometimes to a small pump. A clogged trap, a cracked hose or a failed pump lets water out where it should not be, and can shut the furnace down. Call before it damages the floor or the furnace controls.
Should I close vents in rooms I do not use?
It is better not to close many of them. Forced air systems are designed for a certain amount of airflow, and closing several registers raises pressure in the ducts, makes the furnace run hotter and can trip its high limit switch. Partly closing one or two is fine.
Why do my radiators make noise?
Gentle ticking as the metal warms is normal. Gurgling usually means air in the lines and can often be fixed by bleeding the radiators. Loud banging can mean air, water hammer or, in steam systems, pipes holding water. See boiler repair.
Is it normal for my heat pump to run all the time in winter?
On very cold days, yes: heat pumps run long, steady cycles and lean on backup heat. On mild days it should cycle normally. If it never stops in mild weather, or the house will not hold temperature, have it checked. More on heat pump repair.
What does a flashing light on my furnace mean?
It is a fault code. Count the flashes and pauses, then match the pattern to the chart inside the furnace door. Write it down before turning the power off, because resetting clears it. It is the most useful clue you can give a technician.
Air conditioning and mini splits
Why is my AC running but not cooling?
The usual causes are a dirty filter, a clogged outdoor coil, a failed capacitor or fan motor, low refrigerant from a leak, or a frozen indoor coil. Check the filter and the outdoor fan first. Our AC not cooling page walks through it.
Why is there ice on my air conditioner?
Ice on the copper line or the indoor coil means the coil is getting too cold, usually from poor airflow or low refrigerant. Turn cooling off and run the fan to thaw it, change the filter if it is dirty, and call. Running a frozen system can damage the compressor.
How often should I change my filter?
For common one inch filters, every one to three months. Check monthly during peak heating and cooling seasons, and more often with pets, smokers or remodeling dust. Thicker media filters last longer; follow the label.
What is a ductless mini split, and can you fix mine?
A mini split is a heat pump with one or more wall mounted indoor units and no ductwork. They are common in additions, sunrooms and older homes without ducts. Yes, a technician can diagnose error codes, leaks and weak heating or cooling. See mini split repair.
What temperature should I set my AC to in summer?
Whatever is comfortable, but each degree warmer means less work for the system. Setting it very low does not cool the house faster and can freeze the coil. On humid days, leaving the fan on Auto helps remove more moisture.
Is it bad to run my AC when it is cool outside?
Many central air conditioners are not designed to run when outdoor temperatures are cold, and doing so can harm the compressor. If you need cooling on a cool day, open windows or run the fan instead. Heat pumps and some mini splits are built for wider ranges.
Safety and emergencies
What should I do if I smell gas?
Leave the house right away without touching switches or the thermostat, then call the gas utility or 911 from outside. Once the house is declared safe, call us about the furnace. Full steps are on our emergency page.
Where should carbon monoxide alarms go?
On every level of the home and outside each sleeping area, following the alarm maker’s instructions. Test them monthly and replace them when they reach the end of life listed by the manufacturer. Any home with a gas furnace, boiler, water heater, range, fireplace or attached garage needs them.
My heat went out on a below zero night. What first?
Check thermostat, power, filter and the outside vent pipes, then call. While you wait, open cabinet doors under sinks on outside walls, let those faucets drip, and keep everyone in one warm room with a safely placed electric space heater. Never use the oven or a grill to heat the house.
Can I use a space heater safely?
Yes, with care: keep it three feet from anything that can burn, plug it straight into a wall outlet (not an extension cord), choose one with tip over and overheat shutoff, and turn it off when you leave the room or go to sleep.
What happens to my heat in a power outage?
Gas furnaces and boilers need electricity for their controls and blowers or pumps, so they stop when the power does. Keep warm safely, protect pipes, and never run a generator inside or in an attached garage. The furnace should restart on its own when power returns.
Thermostats and indoor comfort
Why is one room always colder than the rest of the house?
Rooms over garages, at the end of long duct runs, or with several outside walls and older windows lose heat fastest. Check that the register is open and not blocked, and that the return grilles in the house are clear. If it is still cold, a technician can measure airflow to that room and check for disconnected or crushed ducts.
Do I need a smart thermostat?
No, but it can help if your schedule varies. Smart thermostats usually need a C wire for steady power, and they must be set up for your exact system. A heat pump, a two stage furnace or a dual fuel setup each need the right settings. See thermostat repair if a new one is not working.
How dry should the air be in winter?
Very dry winter air causes static shocks, dry skin and gaps in wood floors, while too much humidity causes condensation on windows. Many people aim for a moderate level and lower it during deep cold to avoid window frost. A furnace mounted humidifier needs a new pad and a check each fall.
Why is my house dusty even though I change the filter?
Leaky return ducts in basements or attics can pull in dust from around the filter, and a filter that does not fit its slot lets air slip past. A technician can check the filter rack and returns. Running the fan on Auto rather than On also keeps less dust moving around.
Is it better to leave the heat at one temperature or turn it down at night?
With a gas furnace, a moderate setback at night or while you are away is fine. With a heat pump, keep setbacks small, because recovering from a big drop can bring on backup heat. Either way, never turn the heat off in winter: pipes in outside walls can freeze.
Maintenance and Sioux City weather
How often should my heating and cooling be serviced?
Furnaces and boilers once a year, ideally in early fall. Central air once a year in spring. Heat pumps twice a year, since they work in both seasons. See furnace tune ups and AC tune ups.
Why does my furnace stop after a snowstorm?
If it vents through plastic pipes on the side of the house, drifting snow or frost has probably blocked them, and the furnace shuts itself off as a safety measure. Clear both pipe ends gently by hand, then turn the furnace off for thirty seconds and back on.
Should I cover my outdoor AC unit in winter?
A full wrap can trap moisture and attract rodents. A board on top to keep ice and debris off is usually plenty. Never cover a heat pump, because it runs all winter.
What can I do in fall to avoid a no heat call?
Run the heat on a cool evening in September, change the filter, replace thermostat batteries, clear storage away from the furnace, find your outside vent pipes, test your CO alarms, and book a yearly check before the first hard freeze.
Does cottonwood fluff really matter for my AC?
Yes. In early summer, cottonwood seed fluff can mat across the outdoor coil like felt and choke airflow, making the system run hot and cool poorly. Rinse it off gently with a garden hose with the power off.
Do older Sioux City homes need special care?
Often. Older houses may have boilers and radiators, ductwork added decades after construction, or newer furnaces venting into old chimneys. Have the venting checked, keep radiators uncovered, and tell us the age and type of system when you call.
Didn’t see your question? Call (555) 010-0142, or start with a topic: heating, cooling or emergencies.