In the past we have discussed, debated, and argued the need for chemical backflushing on the E-61 manual group in particular. In my own case I have found that if clean-water backflush is done at the end of each session before the machine is allowed to idle or is turned off that even after two or three months that the buildup under the screen and in the group is minimal.

One factor that I do not remember reading is the effect of not performing detergent backflushing has on the waste drain tube. I had a few stray drips under the machine this AM and wanted to check to make sure that the drain line was properly affixed to the barb fitting. Using a flashlight I noticed that the vinyl drain line had a good buildup of coffee muck. I made a mixture of cleaner and hot water and poured it into the drip tray but it did not clean the hose out. I also ran the hot water wand to replace the water in the steam boiler and to try to clean the hose out that way, but it was not effective as well. So I tipped the machine on it side and removed the hose from the fitting and cleaned it out with the long tube-cleaning brush we use on our CamelBaks. Bending the drain tube slightly this way and that as I ran the brush in and out did the trick.

So if you are a practitioner of the teachings of the school of detergent minimalists, check that drain line.

I'm still learning everything when it comes to home espresso. I hardly ever use my hot water tap, since I'm not plumbed in. Last week, I caved in and used some to reheat a cup that I rinsed in the sink, and forgot that I had the tap water in the sink running cool. The water that came out of my hot water tap was dark grey metallic and freaked me out. It only took a few seconds to purge out, but yuck. If that's not coming from the wand, that means that's what's sitting in my steam boiler?

Refreshing the water in the steam boiler is important to do occasionally for just what you are seeing, but also it can help keep scale under control. If you don't have some sort of treatment or filtering to the water going into the machine you will end up with sediment and mineral buildup in there (ever have to move an old water heater?). If you have a reservoir option, refilling the boiler with distilled water every 3 to six months will keep scale down as the distilled will actually leach some of the mineral content out. There are others here FAR more knowledgeable in this area who can comment further.

I would not use distilled water as the auto-fill sensor needs normal water to detect the water level.

Is that the same as the low water level alarm? Because I disabled that as soon as I set it up. Somehow, I think its not.

Most if not all electronic water level sensors measure the resistance of electrical current to GROUND. Reverse Osmosis usually doesn't and distilled water doesn't have enough minerals in suspension to provide a short circuit to the grounded metal body of the appliance. Pure H2O does not conduct electricity. Thus the sensor can't SEE (tank full) or NOT see (tank low) the water when it touches probe tip. Some minerals also provide aid for the extraction of some of phenols in the coffee oils. The lack of them can diminish some of the flavor in a minor way. Since water is 97% + of the finished brew, addressing specific water problems, ie scale, hardness, chlorine, manganese, whatever, should be done with specific filters. Softened water should be avoided. The minor amount of salt that MAY get through a poorly maintained unit to the coffee can turn some extractions into snot and plug the basket in the worst case.

I can't fully explain why, but the line from a drip tray must have an air gap to the building drain. This is not a device, it is literally a gap allowing the line to DRIP into the drain. I have often seen the lack of this gap cause the drain line to clog over time or not drain at all. Many installation manuals state the need but don't explain what constitutes a gap.

Randy G. wrote:One factor that I do not remember reading is the effect of not performing detergent backflushing has on the waste drain tube.
So if you are a practitioner of the teachings of the school of detergent minimalists, check that drain line.

This causes me to remember a funny line about housecleaning I read long ago. It went:
"Never look under/behind your refrigerator. If you do, you will clean there."
The same for espresso machine drain lines. I use a transparent plastic tube. I looked there and...

I'm glad you posted this since I do nothing to clear the line at present, so I can see a gloppy hassle is preparing its ambush as we speak. Time to add a monthly hot water detergent rinse I think.

Depends where you tie into the drain I imagine although if the household drain is properly vented I don't see why you'd need a "gap" & why the machines drain would have to drip into the drain. I used a standard dishwasher drain fitting which installs directly under the sink. No gap & the water from my machines drip tray pours into the sink drain pipe. No problems with clogs or a dirty drain line in over two years of use. I do use the hot water wand throughout the day & run a detergent clean every 4 days along with nightly plain water backflushes all of which I'm sure helps keep the clear drain line clean.

Like many on here I use a softener cartridge & carbon filter pre machine and haven't had issues with salt in any of my machines in the 4 years I've used this system.

Regarding using distilled or reverse osmosis water in the steam boiler, the autofill sensor should be OK if you "spike" the water with 5-10% tap water. Read Jim Schulman's "Insanely Long Water FAQ" for good advice on keeping the steam boiler scale-free by replacing the water in the steam boiler periodically with distilled water.

The under sink dishwasher drain is gap connection. Open air from the sink drain above and the P-trap in the sink drain below. The dishwasher dumps into an open air breathing tube. Again, i can't explain it completely, but if you plumbed under the sink below the P-trap it often will not drain well.

If you have cleaned your boiler to spanking new condition it will not have any minerals in it. If you are occasionally filling with distilled water you moving the full scale build up down the calendar. Maybe thats enough.

My point was about poorly maintained softeners. Again, coffee is flavored water. Taste your tap water with and or with out your softener. If you like the taste, problem solved or didn't exist. like the roast itself, crap in crap out. The brewer is only responsible for time, temperature, and volume.