The instruction manual says to use a high-temperature silicone for the seal,


The service temperature upper limits for both common silicone sealants and high
temperature sealants is well above the softening point of PVC, so IMO it seems
to be a case of overkill to recommend the high temp variety. Most high temp
formulations are red. If your sealnnt is some other shade or cleas it may be
the conventional variety. HTH

Joe