I've had my Sync water and drain line plumbed for about a year. I've been so happy with it.

A question about cleaning. I have it draining directly into the under sink drain line. I added a p-trap with a clear tube from the machine. I clean the P trap out the other day and boy it smelled awful. Also the clear drain tube is pretty gross looking. I run a bit of hot water through it daily. But is there any special cleaner I could use or technique?

Bleach is cheap. Pour it into the plastic receiver under the drip tray, not into the stainless drip tray. Wipe it off from any Stainless if it splashes.
Let it sit 3 or 4 minutes, then a quick rinse of water down the tube is enough.

Use the C.I.P. cleaning method https://en.wikipedia.org/wiki/Clean-in-place

Many in the beer industry use P.B.W. cleaner. https://fivestarchemicals.com/pbw-cleaner-1bs. I use it often with a few caveats. Go light 1 tablespoon per liter of water and keep under 2 hours as an initial test. I've found that PBW is not good at mineral descaling but does an excellent job on caked on organic soils. For descaling use citric acid powder mixed with water at same volume. Vinegar can be used but leaves an off taste from my experience. This combination works well dealing with the soils and mineral buildup.

Post Edit: It may be easier to replace the line if it's the clear tube you mentioned.

Thanks. The tricky bit is how to let it soak. I'll have to plug one end the drain line, fill it and then uncork it without making a huge mess....

I was also thinking of running some Cafiza coffee cleaner.

Cafiza has been my go-to for cleaning drain lines. I add a scoop directly to the drain box and pour a kettle of hot water over it slowly. As it goes, it foams and does a decent enough job of breaking up the gunk. Cleaning this way more frequently will also help prevent more stubborn buildup. I'm not sure how much it will help the trap itself however. That might be a case for a more prolonged flush to wash out whatever has been sitting there a while.

I use water pressure and put diswasher soap when empty from coffee

I run a hot water solution of Oxyclean every few weeks through mine followed by near-boiling water. I have a ceramic drip tray so no worries for me about metal content, but I use to clean all my Hottop stainless parts with it in a good long, submerged soak without problems other than it removed the red printed-on heat warning on the polished outer cover. Not for use on aluminum though.

I just ordered a 61" flexible tube brush from Amazon. I'm optimistic it's goiig to do the trick. I'll repot back.

We alway preheat cups from the steam boiler hot water spigot that gets poured into the drip tray just before the shot is pulled. Perhaps in addition to flushing crud out from the bottom of the steam boiler this also helps to keep the drain hose clean too or at least lengthening the time between cleaning. We have never had to clean our drain hose yet and it was direct plumbed & drained 5-years ago.

adcampo wrote:I just ordered a 61" flexible tube brush from Amazon. I'm optimistic it's goiig to do the trick. I'll repot back.

This seemed to help clean things up some. I'll keep flushing. Thanks for everyone's input.