Ashburn, VA

How much does it cost to fix or repair a humidifier or dehumidifier?

$70 – $400 average repair cost

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December 8, 2021

Reviewed by Tom Grupa and 2 expert HVAC services on HomeGuide.

Humidifier repair costs

Humidifier repair costs $70 to $400 or $270 to fix on average, depending on the brand, type, and problem. Dehumidifier repair costs $50 to $200. HVAC repair technicians charge a $70 to $100 troubleshooting fee and $75 to $150 per hour to fix a humidifier or dehumidifier.

Humidifier repair cost - chart
Humidifier repair cost - chart

Humidifier repair costs
National average cost $270
Minimum cost $20
Maximum cost $700
Average cost range $70 to $400

Cost data is from research and project costs reported by HomeGuide members.


Dehumidifier repair costs

Dehumidifier repair costs $50 to $200 on average. Some problems like the unit not turning on, not collecting water, or making loud noises require professional HVAC expertise to diagnose and fix. Replacing the unit is best if it is leaking refrigerant or requires new coils.

DIY dehumidifier repairs cost $15 to $50 or more, depending on the issue. Common problems that can be fixed DIY include:

  • Dirty coils causing poor dehumidification
  • Water leakage caused by drain clogs
  • Faulty float switch causing water overflow
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Cost to fix a humidifier by repair type

Humidifier repair costs depend on which part requires replacing and whether the repair is handled by a professional or DIY.

Cost to fix a humidifier by repair type
Repair Part price Total replacement cost
Evaporative filter pad replacement $10 – $30  $10 – $30 (DIY)
Solenoid filter replacement $4 – $10 $4 – $10 (DIY)
Solenoid valve replacement $15 – $80 $90 – $230
Water and float valve repair $15 – $30 $90 – $180
Tank replacement $20 – $200 $20 – $200 (DIY)
Fan motor replacement $25 – $150 $100 – $450
Humidistat replacement $30 – $200 $100 – $400

Technician repairing whole-house humidifier
Technician repairing whole-house humidifier

  • HVAC companies charge a $70 to $100 diagnostic fee to identify the problem. Some companies apply this fee toward repair costs.
  • HVAC technicians charge $75 to $150 per hour for humidifier repairs.
  • Most humidifier repairs take less than one hour once the problem is found.

Humidifier filter or evaporator pad replacement cost

The cost to replace a humidifier filter depends on the filter type:

  • Solenoid filters cost $4 to $10. The solenoid filter strains particulates as water flows from the house water line into the humidifier.
  • Evaporator filter pads cost $10 to $30. Water runs over or through the evaporator filter pad to generate the water vapor released into the air.

Solenoid valve replacement cost

A solenoid valve costs $90 to $230 with professional replacement or $15 to $80 for the part alone. A faulty solenoid valve prevents the water from getting to the humidifier.

Replacing a solenoid valve involves handling electrical and water lines. Always turn off the power before touching the valve or hire an HVAC professional to handle the replacement.

Water and float valve repair cost

A water or float valve costs $90 to $180 with professional replacement or $15 to $30 for the part alone. Drum humidifiers typically require replacing the float valve over time. Try cleaning the part first and replacing it if the issue persists.

Humidifier tank replacement cost

A humidifier tank costs $20 to $200, depending on the type and size, and is DIY replaceable. Single-room humidifier tanks fall at the low end of the price range. A whole-house steam humidifier canister costs $60 to $200 on average and requires annual replacement.

Humidifier fan motor replacement cost

A humidifier fan motor costs $100 to $450 with professional replacement or $25 to $150 for the part alone, depending on the humidifier type. An inoperable fan may be broken or may just not be getting power. Confirm the electrical is working properly before replacing the part.

Humidistat replacement cost

A humidistat costs $30 to $60 for a manual model or $90 to $200 for an automatic digital controller. An HVAC technician or an electrician can replace a humidistat. Electricians charge $40 to $100 per hour on average, plus a $75 service call fee.

Confirm the humidistat is set correctly if the home feels too dry. One or more electrical components may need replacing if the humidifier fails to "click" on after turning the humidistat to its highest setting.
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How to fix common humidifier problems

The most common humidifier problems stem from a clogged filter, incorrect water level, malfunctioning humidistat, or an electrical issue. Most repairs are simple and more cost-effective than replacing the entire unit.

Tip: Always read the manual before attempting repairs, as some actions may void the warranty.

It won't turn on

A frequent cause of a humidifier not turning on is the humidistat failing to sense the humidity level and not triggering the unit to start. Other possible reasons the humidifier won't turn on include:

  • The water level is too low.
  • The drive motor is going bad.
  • The drive belt has stretched out and is slipping.

It’s not turning off

A stuck or broken solenoid valve often prevents the humidifier from turning off. Solenoid valves typically contain a small filter that forces the valve to remain open when clogged. If the unit does not turn off after cleaning the solenoid filter, the valve itself likely needs replacing.

Humidity is not rising

A clogged evaporator panel is the most common cause of humidity not rising. Evaporator pads should be replaced annually or more often in homes with hard water where minerals build up faster. Other potential reasons the humidity is not rising include:

  • The bypass damper is closed.
  • The humidifier pad was installed incorrectly.
  • The humidifier was not sufficiently tuned-up after last season. Tune-ups involved cleaning and lubricating all essential parts.
  • The water level in a drum humidifier is too low.

Leaks

Humidifier leaks are typically caused by a clogged evaporator panel, drain line blockage, or faulty valve:

  • Evaporator panel – A clogged pad prevents incoming water from filtering through and results in water overflowing. A clogged filter panel is the most frequent issue in flow-through humidifiers.
  • Drain line – Drain line tubing that is kinked or clogged causes water backup.
  • Water inlet valve – The inlet valve needs replacement if it stays open after shutting off the power.
  • Float valve – Reservoir humidifiers contain a float valve that shuts off the water when it reaches a specific level. A sticking float valve is a common culprit in drum and reservoir humidifiers and causes water to continue flowing after the reservoir is full.

No steam or mist

A lack of steam or mist is often due to a clogged or broken valve preventing water from reaching the humidifier. If the valves are functioning, the humidistat may need replacing if there is no audible "click" when turned to its highest setting.

Mist problems in an ultrasonic humidifier are usually resolved by cleaning or replacing the membrane.

It’s making noise

Exceedingly loud humidifier noise typically indicates the unit requires cleaning or lubrication. Loose parts or screws may also cause audible vibrations. Regular cleaning and maintenance resolve most noise problems.

It’s freezing up

The most common cause of a freezing dehumidifier is air temperature below 65°. Dehumidifiers are made to operate in temperatures above 65° unless marked explicitly for basements or low-temps. If the room is above 65°, freezing up may be due to low refrigerant, an air blockage, or a faulty compressor.

It smells

Bad smells are most common in reservoir humidifiers due to stagnant water. Regularly cleaning the container is essential to prevent dangerous bacteria and mold growth. Use non-toxic cleaners like vinegar and hydrogen peroxide. Harsh chemicals break down parts and negatively affect air quality.

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Humidifier troubleshooting, cleaning, and maintenance

Humidifier malfunctions often occur due to a lack of routine cleaning and maintenance. Perform these routine maintenance tasks to keep the unit functioning properly. Always follow the owner's manual as deviating from the manufacturer's care instructions may void the warranty.

Always turn off the power and water supplies to the humidifier before any cleaning or maintenance.

Humidifier troubleshooting, cleaning, and maintenance
Frequency Maintenance type
Annually
  • Replace the evaporator filter pad. Check the filter more often in homes with hard water or heavy humidifier use.
  • Check the interior for scaling. Remove mineral buildup with a mild cleanser like vinegar.
  • Remove dust and debris from dehumidifier coils.
  • Check the housing, lines, and junctions for leaks.
  • Tighten or replace loose fittings.
Seasonally
  • Lubricate the fan with machine oil twice per season.
Monthly
  • Clean the reservoir on a drum humidifier to prevent bacteria, mold, and mildew growth.
  • Monitor the reservoir's water level to ensure it does not overflow and stop the unit. An overfilled reservoir typically means a drain or valve blockage.
As needed
  • Clean or replace the membrane in an ultrasonic humidifier if the unit is not producing steam.
Use distilled water to prevent mineral buildup in humidifiers that require manual filling.

Cost factors to repair a furnace or whole-house humidifier

The following factors affect the cost to repair a whole-house humidifier:

  • Type – Standalone humidifiers typically cost less to repair than duct-mounted units.
  • Parts – Individual components may cost as little as $4 or as high as $300. Some parts like the evaporator filter panel are not covered under warranty.
  • Brand – Replacement parts for top brands typically cost more than generic alternatives.
  • Warranty – Most brands include a 5- or 10-year limited warranty that covers parts but not labor. Some brands require professional installation and regular service for the warranty to be valid.
  • Aprilaire – 5-year limited warranty with professional repair and service required.
  • Honeywell – 5-year limited warranty if professionally installed. 1-year limited warranty for retail purchases installed DIY.
  • Carrier – 5-year or 10-year limited warranty, depending on the model.
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Finding and hiring an HVAC repair service

Before hiring an HVAC technician to repair your humidifier or dehumidifier:

  • Get at least three estimates to compare.
  • Look for a NATE-certified technician with experience repairing whole-house humidifiers or dehumidifiers.
  • Browse their reviews on HomeGuide, Google, and the Better Business Bureau (BBB).
  • Select companies that are insured, bonded, and have been in business for more than five years.
  • Ask for references.
  • Avoid selecting the lowest quote as quality may suffer.
  • Get a detailed estimate, contract, and warranty in writing before the work begins.
  • Never pay in full before the project starts. Use a payment plan instead for work completed.

Questions to ask

  • Are you licensed, bonded, and insured?
  • What experience do you have repairing whole-house humidifiers or dehumidifiers?
  • How long will the repair take?
  • Is there a warranty, and if so, what does it include?
  • Would it be better to replace the unit than repair it?
  • What is and is not included in the estimate?
  • What additional costs should I expect?
  • How often do you recommend changing the filter pad?

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