From the time I first saw Surpise I noticed the heads had a peculiar smell. I suspect the hoses have become more permeable although these are thick VETUS sanitary hoses. Note: the holding tank was empty. Has anyone replaced these hoses before?

On rascal, my superseal, no holding tank I have never had any loo smell problems, the only precaution I make is when leaving the boat I always leave the lid up. My idea is that any smells that could build up if trapped can disperse via the venting light in the heads.
Try and remember to close before sailing, I often hear a slam noise on the first starboard tack, if I forget!
Philip

On a 335 the lid may be left open as it is secured by a spring and a shock cord. It never falls unexpectedly … so far. I only close it when I need it as a seat. Normally it is kept open, but still there is a smell. The ventilation hatch in the ceiling is also ajar.