Is your warranty still valid? Find out here. Simply select your disposer model below from the drop down menu and enter the first four digits of the serial number. The warranty period commences from the later of : (a) the date your InSinkErator product is originally installed, (b) the date of purchase, or (c) the date of manufacture as identified by your InSinkErator serial number. For full details, please see your installation, care and use manual.