For anyone still looking I believe the replacement grommet is MoreBeer part number "FE349". The grommet on my thermowell tore the second time I used it; it didn't occur to me as something I needed to be mindful of. I'm currently looking for a replacement and I'd strongly suggest anyone who buy this thermowell buy a couple of replacements at the same time. Thankfully they're cheap!

Another possibility for replacement grommets is McMaster-Carr. It looks like their part no. 9600K34 will be a good replacement. The downside is that these are only sold in packages of 100 for about $16. Pretty much a lifetime supply if you go that route.

Richard I have not needed a new grommet from this fermenter I would assume there has to be you could probably just measure it too and get one online somewhere sorry I couldn't help more

If MoreBeer has a part number I don't know it. Certainly the grommet is the weak link in this assembly. When mine failed I took the failed part to a real hardware store (not a big box chain) where they have grommets in little bins for individual purchase. I was unable to find an exact match but did find something that works: it is a rubber shoulder washer or bushing. Dimensions are as follows: top OD 0.75" bottom OD 0.5" hole diameter 0.25". When using it first put the rubber part into the hole with the large part on top. Then use a little keg lube on the outside of the airlock and insert it into the hole. It will be a snug fit and that will expand the bushing to make a gas tight seal. It's working well on the current batch of beer. I bought two such bushings to have a spare. Good luck. If you find something better let the rest of us know.

Just get the spigot FE785. My original spigot failed after 6 years (no complaints... its a plastic piece that just finally wore out - crack on underside of white part leaked about 6 oz on kitchen floor when kegging last night). I have a spare spigot part already on hand because I got this spigot when I got this thermowell.

Hello Brent We currently do not carry spare locknuts for the Speidel FE746. We do offer a spare solid locknut or one can be used from FE785.

You can reverse the two caps that came with the fermenter or buy an additional spigot/cap (FE785) and remove the spigot part.

I use this on my 30L round Speidel and it works perfectly.

Works fine with my 7.9 gal. round fermenter. Just need the locking ring and O-ring from (another) spigot assembly.

These will work for both the round and rectangle Speidel fermenters.

The thermowell is 11.5 inches long starting from the bottom side of the metal disc to the point where the unit begins to pinch. It will reach the middle of both 60L Speidel Plastic Fermenters (FE720 & FE730). We're unaware of the STC-100's probe dimensions but the inside diameter of the thermowell is 0.25 inches.