[. . . ] DO NOT install the EF-AUTO Series fans where the temperature of air within the duct exceeds 150 degrees F. Locating the fan near the end of the duct will provide the most efficient performance. IMPORTANT: For proper operation of the PRC sensing control, do not install the EF-AUTO within 10 duct diameters from outlet end supply register. [. . . ] If 115 VAC power is supplied to outlet and EF-AUTO does not run follow the steps below. Block register at end of EF-AUTO duct run and turn on air handler fan/blower. If EF-AUTO turns on with register blocked, verify furnace filter is clean. Replace filter if dirty and see if EF-AUTO turns on when air handler fan/blower is running. If filter is clean, move EF-AUTO closer to the Air handler fan/blower to see if higher pressure turns EF-AUTO on. CAUTION: You will need to check for voltage across PRC control to proceed. With forced air handler fan/blower running, check for 115 VAC across M1 & M2 on PRC sensing control, (See Diagram C). @ 800-255-4208 for further assistance. FOLLOW THE STEPS BELOW FOR AN EXISTING INSTALLATION: It may be necessary to measure voltage during troubleshooting. If EF-AUTO fan does not run when the forced air handler fan/blower is running, verify 115 VAC power is supplied to the outlet the EF-AUTO is plugged into. If 115 VAC power is supplied to outlet and EF-AUTO does not run follow the steps below. Use a small screw driver to carefully pry sensing tube off of PRC sensing port while at the same time pulling on sensing tube, (See Diagram D). Use compressed air or blow in sensing tube going to sampling port in EF-AUTO housing, (See Diagram E). Replace tubing, plug in EF-AUTO, wait 30 seconds and turn air handler fan/blower on to see if EF-AUTO turns on. Block register at end of EF-AUTO duct run and turn on air handler fan/blower. [. . . ] EXPRESSLY DISCLAIMS LIABILITY FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING FROM THE USE OF THIS PRODUCT. THIS WARRANTY IS IN LIEU OF ALL OTHER EXPRESS WARRANTIES AND NO AGENT IS AUTHORIZED TO ASSUME FOR US ANY LIABILITY ADDITIONAL TO THOSE SET FORTH IN THIS LIMITED WARRANTY. IMPLIED WARRANTIES ARE LIMITED TO THE STATED DURATION OF THIS LIMITED WARRANTY. [. . . ]