Read the humidistat manufacturer’ s installation and operating manual for troubleshooting problems, their possible causes, and their suggested remedies. In most cases, they will be specific to the type of humidistat (electromechanical, electronic, or pneumatic) and the model. Some very basic troubleshooting problems that apply uniformly to all humidistats are listed in Table 4-4.
Table 4-4 Troubleshooting Humidistats
| Problem and Possible Cause | Suggested Remedy |
| Slow response. | |
| (a) Humidifier installed in a dead air space. | (a) Relocate to appropriate location. |
| (b) Inadequate airflow caused by an incorrect cover. | (b) Install a correct cover. |
| Inaccurate reading. | |
| (a) Backplate too tight. | (a) Retighten. |
| (b) Humidistat installed on inside surface of an outside wall. | (b) Move to appropriate location. |
| (c) Humidistat installed near heat source. | (c) Move nonpermanent heat source (lamp, TV set, etc.) away from humidistat or move humidistat away from permanent heat source (constant sunlight, fireplace, stove, etc.). |
| Constant readings. | |
| (a) Defective humidistat. | (a) Replace humidistat. |
| (b) Incorrectly calibrated humidistat. | (b) Recalibrate humidistat. |
| (c) Humidistat is undersized. | (c) Replace the humidistat with a correctly sized one. |
