i assume you mean heated mattresses, not pads, since that's what FR puts in their popups/hybrids.
if the trailer is still under warranty, the dealer should replace them.
if it's not, contact the mattress manufacturer.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC