Here’s our simple humidifier troubleshooting guide to help when your furnace humidifier is not working. 

1. The Humidifier Won’t Turn On 

If your humidifier either won’t turn on or turns on and off again, it is often a power issue. Check for any tripped circuits or blown fuses at your fuse box. If this is the issue, switch the tripped circuit back to on or replace the fuse. If this isn’t the issue, some humidifiers have a control lock feature. Check to see if this is activated and turn it off. This should turn the humidifier on. If not, go to problem #2.    

2. Furnace Humidifier Leaking 

Humidifier leaks cause the water levels to drop below the minimum, so the system stops. If there is water on the floor, tighten any components that seem loose. If this doesn’t work, it could be a cracked tank. Call your HVAC technician to come and assess the issue.   

3. No Water 

No water flow means there’s something wrong with one of the valves. Check the following: 

  • ​Ball valves should have the handle aligned with the pipe. 
  • Gate valves should be turned all the way counterclockwise. 
  • Saddle valves could be obstructed. 
  • Solenoid valves should click when you set your humidistat to high. 
  • ​Float valves might gunk up so they don’t function properly. Move it up and down at the tray to help get it working. 

If none of these steps work, call your HVAC technician for an evaluation.   

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4. Odours 

Pathogens can grow in the water inlet and drainage trays of your humidifier, causing musty odours. When mould growth is present, it circulates through your ducts leading to bad air quality in your home. Steam generators in humidifiers can also lead to mould growth as the mould is circulated in the steam and then through your HVAC ducts.  

When the steam condenses, the heat from the steam combined with the water creates the perfect storm for mould growth. Once mould is present in ducts you will need professional cleaning to disinfect the ducts. Your best bet is to prevent mould and other odour causing bacteria: 

  • Clean your humidifier’s water trays regularly 
  • Clean your evaporator pad or drum with bleach or vinegar every few months 
  • Clean the inside of the humidifier housing, inside of the inlet and outlet vents 

If this is too complicated, you should call your HVAC technician to perform a professional cleaning. 

5. Humidifier is Not Humidifying 

This depends on the type of humidifier: 

  • Drum: If you hear humming coming from a drum-style model it could be the motor. If it sounds more like a knocking it is the actual drum. 
  • Steam: For steam generators, it could be your power supply as it isn’t heating up the elements. Check the breaker again to see if this is the problem.   
  • Evaporator pad: If your system has an evaporator pad, it could be mineral buildup blocking water flow. Clean the pad using vinegar. If this doesn’t work, it needs to be replaced. 
  • Filters: If the furnace humidifier filter is dry, it needs to be cleaned or replaced.

The best way to avoid trouble is to have annual tune-ups and cleaning by an HVAC technician. Contact the HVAC Experts at Dunn Heating ClimateCare today to assess your home and offer the best solutions available. 

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