Yes, you can replace a gas wall heater with a mini split. In a Los Angeles house with no ducts, it is usually the simplest way to get heating and air conditioning from one system. The thing to plan for is coverage: a wall furnace in the hallway warms the middle of the house, while a mini split conditions the room its indoor unit is in.
Key takeaways
- A mini split is a heat pump. It heats and cools, where a wall furnace only heats.
- It burns nothing indoors. ENERGY STAR notes a heat pump produces no carbon monoxide in the home.
- Replacing one wall heater usually takes more than one indoor unit.
- The old furnace can stay as a backup, be shut off and left in place, or be removed and the wall patched.
- Rebate eligibility depends on your utility.
Can a mini split replace a wall heater?
Yes. A ductless mini split heat pump moves heat instead of making it by burning gas, and it reverses in summer to cool. ENERGY STAR describes ductless heat pumps as best suited to homes without ductwork, which describes most Los Angeles houses that still rely on a wall or floor furnace.
A typical call to our office: a three-bedroom house in Torrance whose only heat is an old wall heater that no longer works, with no air conditioning at all. One project replaces the heat and adds the cooling.
Wall furnace vs mini split
| Factor | Gas wall furnace | Mini split heat pump |
|---|---|---|
| Heating | Yes | Yes |
| Cooling | No | Yes |
| Energy source | Natural gas, burned inside the furnace and vented outdoors | Electricity. Nothing is burned. |
| Where the heat goes | The room or hallway the furnace faces | Each room that has an indoor unit |
| Temperature control | One setting for the house | A separate setting for each indoor unit |
| Routine upkeep | SoCalGas advises having a gas furnace checked at least once a year | Wash the filters when they are dirty, plus periodic professional cleaning |
How many indoor units replace one wall heater?
Count the rooms you want comfortable with the doors closed. A wall furnace heats one area and relies on open doors to spread warmth, so bedrooms at the end of the hall run cold. A mini split does not share air between rooms either, but you can give each room its own unit.
- Small one-bedroom house or apartment: one unit in the living area, and a second in the bedroom if the door stays closed.
- Two or three-bedroom house: one unit in the living area plus one in each bedroom you want conditioned, all on one multi-zone outdoor unit.
- One problem room: a single-zone system for that room, keeping the wall furnace for the rest of the house.
Do you need a mini split in every room? explains where you can use fewer units.
What happens to the old wall heater?
You have three choices, and the right one depends on the furnace’s condition and how much wall work you want.
- Keep it as a backup. If it works and is safe, it can stay. Keep having it checked every year.
- Shut it off and leave it in place. The gas line is capped and the cabinet stays in the wall. This is the least disruptive option.
- Remove it. The furnace and its vent come out, the gas line is capped and the wall is framed and patched to match the plaster or drywall.
Gas line: have it capped by a licensed contractor. Turning the valve off and covering the furnace is not the same thing. Ask during the consultation whether removal and wall patching are included in the quote.
If you are not sure the existing furnace should be running at all, read is my wall or floor furnace safe? SoCalGas says a yellow, large and unsteady flame means the furnace needs immediate inspection by a licensed professional.
What the installation involves
Each indoor unit connects to the outdoor unit through one hole of about 3 inches, which carries the refrigerant lines, the drain and the control wire. There is no ductwork to build, which matters in homes with plaster walls and no attic space to spare.
- Electrical: the system needs a dedicated circuit. A single-room system of 9,000 or 12,000 BTU is available in 115 volts. Multi-zone systems need a 230-volt circuit.
- Outdoor unit: one outdoor unit can serve several rooms. See where a mini split outdoor unit should be installed.
- Permit: in the City of Los Angeles, a mechanical permit is required to install or change a heating or cooling system.
Cost and rebates
The price depends mainly on how many rooms get an indoor unit. How much it costs to install a mini split covers what moves the number.
Rebates for switching to a heat pump are run by the utilities and the air district, and the terms change during the year. Check the current rules on our LADWP Electrification Program, SCE heat pump rebate and SCAQMD rebate pages.
Frequently asked questions
Can I replace my furnace with a mini split?
Yes. A mini split heat pump can be a home’s only heating system in Los Angeles, and it adds air conditioning. Plan on an indoor unit in each room you want conditioned with the door closed.
Do I have to remove the old wall heater?
No. It can stay as a backup, or be shut off with the gas line capped and left in the wall. Removal and patching is optional.
Does a mini split use gas?
No. A mini split runs on electricity and burns nothing, so it produces no carbon monoxide inside the home.
Will a mini split heat as well as a wall furnace?
In most homes it heats more evenly, because each room with an indoor unit has its own heat and its own temperature setting. A wall furnace heats the area in front of it.
How much does it cost to replace a wall heater with a mini split?
It depends on how many indoor units you need. A single room is a single-zone installation. Replacing the heat for a whole two or three-bedroom house is a multi-zone project.
Ready to retire the wall heater?
Book a free in-home consultation. We look at the layout, the panel and the old furnace and tell you how many indoor units the house needs. Dr. Ductless has served Southern California since 2001.
Call (213) 916-0005 Mini split installation in Los AngelesSources
- ENERGY STAR, Ductless heating and cooling
- Southern California Gas Company, furnace maintenance guidance
- Los Angeles Department of Building and Safety, Mechanical HVAC permits
Buying an older home with a wall or floor furnace? Have the heating checked before close of escrow. Our sister company handles heating inspections in Los Angeles.
