Circuit Board with wiring harness for whole house fan-powered humidifiers. Includes wiring harness. Replacement circuit board with transformer for many brands/models of whole house humidifiers. Same as Aprilaire 4238. Board includes relay and transformer that supply 115V to fan motor and 24V to solenoid when system humidistat switch calls.
Related products
![[2 Pack] Impresa Replacement Gaskets for ResMed AirSense 10 Water Chamber – Impresa CPAP Machine Gasket for ResMed AirCurve 10 Supplies Humidair – CPAP Water Chamber Gaskets – CPAP Machine Supplies](https://www.reelksbcstore.shop/wp-content/uploads/2026/08/26f3648a16d90f31078a15615836ad86ff5bf1aedf8b0fc17215a826dcae2693-247x247.jpg)
![Alternative view of [2 Pack] Impresa Replacement Gaskets for ResMed AirSense 10 Water Chamber – Impresa CPAP Machine Gasket for ResMed AirCurve 10 Supplies Humidair – CPAP Water Chamber Gaskets – CPAP Machine Supplies](https://www.reelksbcstore.shop/wp-content/uploads/2026/08/a5e70f0cfbcd50d61274a8c857460c2c147173e1117fed66beb6c2cd5936ef21-247x247.jpg)
