Inspection Training

How to (NOT) Inspect the Humidifier at the Heating System

While the inspector is at the heating system they should inspect for the presence of a humidifier. Inspection of the humidifier is outside the scope of a home inspection but we should still check to make sure it is installed securely and there are no signs of leaking. Please review the entire procedure below.



International Standards of Practice for Performing a General Home Inspection


3.4. Heating


I. The inspector shall inspect:

A. The heating system, using normal operating controls.


II. The inspector shall describe:



III. The inspector shall report as in need of correction:

B. The heating system was deemed inaccessible.


IV. The inspector is not required to:

A. Inspect or evaluate the interior of flues or chimneys, fire chambers, heat exchangers, combustion air systems, fresh-air intakes, humidifiers, dehumidifiers, electronic air filters, geothermal systems, or solar heating systems.


Axium SOP Differences

Axium Requires: Same as NACHI Standards of Practice.


Tools Needed

No tools required to inspect the Humidifier.


  • We don’t inspect humidifiers so if there is one present we will just check to make sure that it is secured, not damaged, and shows no signs of leaking. We would still want to point those items out as defects to the client. There is one picture required for this section and it should just show the humidifier location.


Common Defects

  • There are no defects for this section because we do not inspect humidifiers. We still want to look at it for any general damage or leaking and inform the client if it looks like there are any issues with the humidifier.


Common Mistakes

  • Not using the prewritten “Not Inspected” comment for humidifiers.
  • Not checking for any leakage of the humidifier.


Report / Software


  • N/A


  • The heating system had a humidifier attached. In accordance with the Standards of Practice, the inspector does not evaluate humidifiers. Humidifiers are designed to raise relative humidity levels in properties located in dry climates by adding moisture vapor to air heated by the furnace. Because a warm moist environment such as that which exists in humidifiers can promote the growth of bacteria, yeasts, and molds, the housing, condensation tubes and pumps must be kept clean.


  • The heating system did not have a humidifier installed at the time of the inspection. A humidifier is an upgrade component on the heating system and is not installed on every unit.


  • N/A