An air purifier helps rid your home of dirt, dust, pet hair, and other pollutants. This Fix-It Guide on air purifier repair tells how an air purifier works, what often goes wrong, how to identify an air purifier problem, and what parts and tools you will need to fix it. It then gives simple step-by-step instructions for how to disassemble a mechanical air purifier, how to clean a foam filter, how to replace ionizer wires, and how to test an air purifier precipitating cell. This guide also refers to electrical cord repair, motor repair, appliance controls repair, and fan repair for more specific repairs.
How Does an Air Purifier Work?
An air purifier is a small appliance designed to filter airborne pollutants from indoor spaces. Although dust is most noticeable where it settles and collects, the average home has about three million dust particles suspended in every cubic foot of air. Scary, isn’t it?!
There are two types of air purifiers: the mechanical type and the electronic type. Both come in small-room and whole-house models. In a typical mechanical air purifier, a blade fan or a squirrel-cage fan draws air through a series of filters, including a prefilter (to remove the largest particles), one or more activated carbon or charcoal filters (to remove smaller odor-causing particles), and maybe a type of HEPA ( high- efficiency particulate- arresting) filter. Some mechanical units include an ion generator to charge remaining dirt particles, causing them to adhere to room surfaces.
The most effective kind of air purifier uses an electrostatic precipitator to remove very fine particles, such as cigarette smoke and pollen, from the air in a room. The precipitator gives air particles a positive charge and then traps them with a negatively charged grid. The purifier also may contain filters to remove dust and odors, as well as an ionizer to add negative ions to the clean air. The ionizer supplies a strong negative charge to one or more parts called needles. An intense electric field is developed at the point of a needle, and it creates ions in the atoms in the air. Positive ions are attracted to the needle, while negative ions flow outward. Don’t worry, there won’t be a quiz.
What Can Go Wrong with an Air Purifier?
Lots of things can go wrong with air purifiers. Fortunately, most of them are common problems that you can easily fix. The electrical cord may fail, the motor may fail, the switch may be faulty, the fan may be loose, or the motor shaft may be frozen. In addition, the precipitating cell may become dirty, motor bearings may be dry, filters and air intakes may be clogged or dirty, collector plates may be bent, and ionizer wires may be broken. You probably can fix any of these problems yourself.
Do not operate an electronic air purifier or a mechanical purifier with ionizer needles in a room with oxygen equipment or where combustible gases are present. Also, handle a precipitating cell carefully; it contains sharp metal edges and delicate parts.
How Can I Identify an Air Purifier Problem?
The first step in solving a problem is defining it.
- If the unit does not run or runs sluggishly, make sure power is on at the outlet and test and replace the electrical cord if faulty. Test the motor and replace or service if needed. Make sure filters are installed according to manufacturer’s directions. Inspect and service the switch as suggested in the Appliance Controls Fix-It Guide. Check for a broken fan hub or loose setscrew on the fan (either one would allow the fan blades to spin freely on the motor shaft); replace a fan with a broken hub and tighten the setscrew. Try to turn the fan blades by hand; if the motor shaft sticks, lubricate the motor bearings.
- If an electronic air purifier hisses, crackles, or pops excessively, remove and clean the cell following the manufacturer’s directions.
- If the unit is noisy in other ways, lubricate the motor bearings, tighten the fan on the motor shaft, and remove any obstructions that might be hitting the blades.
- If the air purifier fails to clean air, first check the owner’s manual for air purifier capacity and compare it with your room size; replace the purifier with a larger capacity unit if necessary. Check and clean or replace filters (below); position inlet and outflow sides of the unit away from obstructions like walls, drapes, and large furniture; vacuum dust and lint from filter covers and air passages; remove the precipitating cell (electronic filters only) and examine the plates; they should be flat and uniformly spaced; if necessary, have the plates repaired professionally or install a new cell. Test a precipitating cell (electronic purifiers only) and replace it if necessary. Locate and replace broken ionizer wires (electronic purifiers only).
- If there is an ozone odor in the room (electronic purifiers only), look for a defective collector plate or ionizer wire. If the unit is new, however, a slight odor may be noticed for the first few weeks.
Place an air purifier near the source of pollutants if possible. Position it so that cleaned air blows out toward the occupied parts of a room. It’s best to run an air purifier continuously to get the greatest benefit from it.
What Do I Need for Air Purifier Repair?
- Vacuum cleaner
What Are the Steps to Air Purifier Repair?
Disassemble a mechanical air purifier:
- Turn off the unit and unplug it. Press the release buttons to remove the intake grilles containing foam pre-filters; then remove the filters.
- Remove any screws holding the filter housing in place. To access the fan, remove the long screws holding the main housing together, and separate the halves.
- Remove the fan by prying or twisting the locking ring from the end of the motor shaft; you probably should wear safety goggles for this step. Be careful not to bend the ring as you remove it.
- Remove the screws holding the switch and the motor housing together. Then pull the housing apart to expose the motor. The switch module will now slide out from the channels in the housing.
Clean an air purifier foam filter:
- Remove the intake grill from the air purifier.
- Gently vacuum the filter through the grille.
Replace air purifier ionizer wires:
- Unplug the air purifier and pull out the precipitating cell.
- Use needle-nose pliers to unhook the wire spring from the connector at each end of the cell; if necessary, depress the connector with a screwdriver to free the wire.
- Reverse the procedure to install the new wire.
Test an air purifier precipitating cell:
- Remove the precipitating cell from the air purifier.
- Set the multimeter on RX1 (resistance times 1) to test resistance.
- Clip one tester probe to the cell frame and touch the other probe first to the ionizer terminal, then, in turn, to each of the two outer collector terminals. A reading of 1 (infinity) indicates that the cell is okay. A lower ohms reading indicates a short circuit; replace the unit.
Here are some cleaning tips to help you breathe easier and cut down on the times you have to fix your air purifier:
- Clean the pre-filter in all purifiers, and the precipitating cell in electronic purifiers, frequently.
- Clean ion-emitter needles about every other month by gently wiping with a cotton swab dipped in rubbing alcohol.
- Replace the activated charcoal filter every three to six months, or according to manufacturer’s instructions.
- Replace HEPA filters at least once a year.
- Vacuum the inside of the purifier cabinet or wipe it gently with a damp cloth to remove dust each time you replace or clean any filters.