January 09, 2023 1 min read
We sell tons of big blue filter housings. They're ultra-versatile, easy to install, and tend to be pretty much immune to failures or defects. But every once in a blue moon we'll get a customer who has an issue with one. Usually this manifests itself as a housing that won't seal properly. Once all avenues have been exhausted (replacing o-ring, inspecting threads, tightening the housing with the wrench) it can be concluded that there's some kind of manufacturer defect and a warranty can often be claimed.
In order to claim a warranty the age of the housing needs to be established. This is done by looking at a date stamp that is molded into the plastic at the time of manufacturer.
A Pentek big blue filter housing will have a date stamp in two locations - on the inside of the sump (the blue part) at the very bottom, and on the inside of the cap:
Looking down into the bottom of the sump to see the date stamp
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 The date stamp on the underside of the black cap
The date stamp is comprised of an inner arrow with a number on either side which denotes the year it was manufactured - in this case 2022. The arrow in the date stamp points to the month of manufacture. So this housing was made in November of 2022.