Hello - I work for a HOA community where we have a pool house w/"commercial" or tankless commodes.

I have found a leak on two of the commodes (been cold but not freezing) - in any case, they are both leaking out of the large, screw on top...

They flush fine - just a slow drip leak. I thought about adding pipe sealant but worry that will get into the flush valve or clog the pin hole.

I also checked the vacuum breaker - it was replaced not that long ago and seems fine. I've also replaced the top piece on one of the commodes last year...

Any help would be appreciated! Thank you,
Scott

Are you referring to Flushmeter valves ? Can you post a photo ? Thanks