# I made my whole-home humidifier slightly less terrifying Source: https://www.youtube.com/watch?v=tCVsyY5TRQI Recap page: https://rapidrecap.app/video/tCVsyY5TRQI Generated: 2025-12-25T17:04:53.737+00:00 --- ## Quick Overview The speaker successfully installed a newer Aprilaire Model 60 digital humidifier controller in place of an older analog controller, wiring it to control both the humidifier and the furnace blower fan simultaneously, which solved the issue of the old controller causing water leaks by running continuously during heating cycles. **Key Points:** - The existing Aprilaire Model 700M humidifier controller was replaced with a newer Model 60 Automatic Digital Humidifier Control to solve recurring water leaking issues. - The original analog setup required the humidifier to run only when the furnace was actively heating, but the faulty analog controller caused the humidifier to run continuously during heating calls, leading to excessive water waste and potential damage. - The new digital Model 60 controller requires wiring to both the humidifier's water valve (HUM terminals) and the furnace control board's fan terminal (G) to ensure the blower runs whenever the humidifier is called upon. - The speaker used a 50-foot fish tape to run the necessary external temperature sensor wire through the furnace intake pipe, which was an awkward path requiring careful maneuvering. - The outdoor temperature sensor wire was successfully connected to the new digital controller's appropriate terminals, allowing it to adjust the target humidity based on outdoor temperature as per Table 2 in the manual. - After wiring and testing, the new digital controller correctly activated the humidifier when humidity was low and correctly shut it off when the humidity target was met, even when the furnace was running. - The speaker noted that the old analog controller was likely malfunctioning because it failed to stop the humidifier when the furnace blower was not running during heating cycles, leading to condensation and wasted water. ![Screenshot at 2:22: The humidifier unit is open, showing the saturated media pad and the external fan module being held separately, illustrating the evaporative mechanism being worked on.](https://ss.rapidrecap.app/screens/tCVsyY5TRQI/00-02-22.jpg) **Context:** The video details the process of upgrading an older Aprilaire whole-home bypass humidifier controller (likely a Model 700 series) to a newer, more advanced Aprilaire Model 60 Automatic Digital Humidifier Control. The motivation was to fix a persistent issue where the old analog controller caused the humidifier to run excessively during furnace heating calls, leading to water waste and condensation issues. The upgrade required running an external temperature sensor wire through the furnace ductwork and correctly wiring the new digital controller to both the humidifier's water valve and the furnace control board's fan signal wire (G terminal). ## Detailed Analysis The speaker replaces an old analog Aprilaire humidifier controller with a new digital Model 60 controller to resolve issues where the old unit would run continuously during furnace heating calls, causing excessive water waste and potential condensation damage. The critical step involves rewiring the system to allow the digital controller to manage both the humidifier valve and the furnace blower fan simultaneously. The speaker used the furnace's G terminal (fan signal) on the control board to ensure the blower runs whenever the humidifier is active, a feature the old controller failed to manage correctly. The installation also required running a new outdoor temperature sensor wire through the furnace intake ductwork, which was challenging due to tight spaces, requiring the use of a 50-foot fish tape. The speaker notes that the new digital controller uses an outdoor temperature sensor to adjust the target indoor humidity based on a chart in the manual, preventing condensation when it's very cold outside. After wiring, testing confirmed that the new setup correctly engages the humidifier only when needed, even when the furnace blower is running, and it shuts off when the humidity target is met, unlike the old unit which continued to run, wasting water. ### Humidifier Failure & Replacement Rationale - The old analog controller caused the humidifier to run continuously during heating cycles, leading to wasted water and potential condensation/mold issues - The speaker replaces it with a newer Aprilaire Model 60 Digital Humidifier Control. ### Wiring the New Controller - The new digital controller requires wiring the humidifier's water valve to the HUM terminals and the furnace blower signal (G terminal) to the furnace board to force the fan on during humidification. ### Outdoor Sensor Installation - The speaker used a 50-foot fish tape to run the new outdoor temperature sensor wire through the furnace intake ductwork because the existing ducting was too complex for the required length. ### System Operation Check - After wiring, the speaker tests the system by setting the dial to force the humidifier on; the water valve opens and the humidifier runs, and the relay clicks when the humidity set point is reached, confirming correct operation. ### Programming and Comparison - The digital controller automatically adjusts the target humidity based on the outdoor temperature reading (referencing Table 2 in the manual), a feature absent in the older analog controller, which was manually set or relied on the furnace's heat cycle. ![Screenshot at 00:02: The Aprilaire whole-home humidifier unit attached to the HVAC ductwork in the basement.](https://ss.rapidrecap.app/screens/tCVsyY5TRQI/00-00-02.jpg) ![Screenshot at 00:11: A close-up of the humidifier's internal components, showing the filter pad inside the housing.](https://ss.rapidrecap.app/screens/tCVsyY5TRQI/00-00-11.jpg) ![Screenshot at 00:49: The speaker presenting the AirCare \(a different brand\) portable humidifier, contrasting it with the whole-home unit.](https://ss.rapidrecap.app/screens/tCVsyY5TRQI/00-00-49.jpg) ![Screenshot at 01:45: The speaker holding up the old, discolored humidifier pad, showing the mineral deposits \(calcium\).](https://ss.rapidrecap.app/screens/tCVsyY5TRQI/00-01-45.jpg) ![Screenshot at 06:13: A close-up of the new digital thermostat's wiring terminals, with wires connected to R, C, W, and HUM terminals.](https://ss.rapidrecap.app/screens/tCVsyY5TRQI/00-06-13.jpg)