My pump has been stalling every once in a while. I read that this might be a scale issue. I pulled the mushroom out, which had some scale on it. I cleaned it. I have ordered a water softener and filter to plumb the machine in, so I'm not worried about additional scale.
The question now is whether the scale buildup is significant enough to go through a full descaling procedure, or whether it is mild enough that preventing additional scale would be sufficient.
I have attached pictures of the mushroom - what say you?
Do you live in a hard water area (medium, hard, very hard)?
How old is the machine (did you acquire it new)?
How much do you use it?
By pump stalling what exactly do you mean?
Do you use the hot water boiler as a kettle (if you do how much water do you use per day), or just for steaming (if just for steaming, how often do you refresh the boiler water)
Have you ever descaled it (if so what part/parts)
Scale is the enemy of the coffee machine, but looking at the mushroom it's probably not bad enough for the pump to have scaled, as the pump is working in cold water scale does not form as badly, although it can happen. The questions above are pretty critical in getting decent advice e.g. if you machine is heavily used and 3 to 5 years old, the pump might need replacement. Or pump stalling (whatever that is exactly) might be misinterpreted by you and by me and could be due to an airlock, kinked inlet pipe, blocked in-line softener...anything. When pumps fail or are failing they often have a problem when under load and not when flushing water through the group, but again not always the case.
The other questions will indicate the likely level of descaling in different part of the machine and the techniques for descaling them are different. e.g. in your model of Andreja the expansion valve is on the hot side (not the best place) and they do scale up a bit, hence the screeching you sometimes get. These machines often benefit from a lengthy backflush with descaler in the brew system to get the descaler through this expansion valve.
Aggressive descaling too often is not good for any espresso machine, in fact think of descaling as death by a thousand cuts if done too often. Then it's down to what descaler you want to use, some have buffer salts that prevent copper leaching, others are environment and people friendly, but need care and don't work quickly., but will plate out some copper....although not a problem. Then when you descale, it's absolutely essential to lubricate within the E61 group cam area and group valve pins (if you don't you get a lot of wear and a very stiff lever.
sheepdot Senior Member Joined: 17 Jun 2007 Posts: 62 Location: Maryland, USA Expertise: Just starting
Espresso: Andreja Premium Grinder: Baratza Vario Drip: AeroPress
Posted Sat Jan 12, 2013, 7:24am Subject: Re: Andreja Premium Descaling necessary?
My area is medium, at least according to the Water Company. When I initially bought the machine I did a water test, and I thought it was soft enough that I didn't need to soften it, but apparently not quite soft enough.
The machine was purchased in 2007, and was owned briefly by someone before me. I bought it directly from Chris' Coffee.
I generally pull 1-3 shots five days a week.
One in every ten or fifteen shots, the pump will suddenly get quiet in the middle of the shot, and the flow will decrease. Then it'll kick back in after about five seconds, and the flow will increase again.
I have used it as a kettle - probably a liter or two a day. My roommate was the one who did that, so I didn't keep track of it.
No, I've never descaled it, other than the mushroom and the mushroom chamber, last night.
DavecUK Senior Member Joined: 21 Sep 2005 Posts: 941 Location: UK Expertise: I love coffee
Posted Sat Jan 12, 2013, 8:33am Subject: Re: Andreja Premium Descaling necessary?
Never use an expensive espresso machine as a Kettle, the $20 kettle does a far better job. You will have proportionally more scale in the steam water tank than in the mushroom. So a full descale is probably best, including the brew circuit. I would backflush some descaler through the expansion valve as well as it's quite a long time since a descale. Citric acid can make an good descaler, you will get a little copper leaching and copper plating with it. Commercial descalers have buffer salts which help prevent this, but are usually quite aggressive. You will of course need to descale the steam boiler by draining it before filling the holding tank with descaler.
By the time you have finished descaling enough descaler will have been run through the pump to have had some effect. Your machine is old enough and well used enough to be a candidate for a new Vibe pump, it's just possible that it's beginning to fail. 5 years use before replacement is not usual but it can happen, normally 7 - 9 years.
However, there is another possibility/probability, it could simply be the autofill solenoid for the steam boiler opening and when that happens you can get symptoms similar to what you describe (although the pump doesn't necessarily go much quieter). It's the 5 seconds stall that makes me think it could be this, because that's about exactly the length of time an Andreja will autofill the autofill probe tip becomes exposed. Now it sounds like your pretty switched on and would have thought of this, you would have ensured that the steam boiler didn't need a fill prior to the shot. If so it could be as simple as a bad connection on the wire leading to the autofill probe, or the probe tip simply needs cleaning (an easy job). Now you could test this by earthing out the probe, so it cant autofill (ensure the steam boiler is completely full)....pull 20 shots and if it doesn't stall......but you would really need to know what you are doing so you don't damage yourself or the machine.
Another safer one is: Draw a little water from steam boiler, to make it autofill. When it has do, 20 x 30 second backflushes, wait 30 seconds between each one, see if the pump stalls. Not drawing cold water though the HX will make the steam boiler level remain constant and no autofill should kick in (unless you have a bad connection).
sheepdot Senior Member Joined: 17 Jun 2007 Posts: 62 Location: Maryland, USA Expertise: Just starting
Espresso: Andreja Premium Grinder: Baratza Vario Drip: AeroPress
Posted Sat Jan 12, 2013, 2:35pm Subject: Re: Andreja Premium Descaling necessary?
Thanks, that's very helpful. I'll start keeping notes. When doing some backflushes today, I realized how much quieter the pump gets when the machine chokes, so I'm starting to be less sure of my own reporting. I may start recording some of my pulls to make comparisons.
I think I will go ahead and do a full descale, as well, although I will probably wait for a month or so until I have the necessary block of time to read everything over and do it properly.
Your comment about using an expensive espresso machine as a kettle is probably accurate, now that I think about it, but it was so darn convenient to just have hot water on tap for aeropress coffee. That was actually part of the reason I wanted to plumb the unit in. Oh well!
Thanks again for the detailed response, and I'll provide more details later when I have more solid information.
The problem is occurring more frequently. I'm making sure to run the hot water enough to trigger a fill of the steam boiler, as I realized that I've been leaving the machine on during the day much more lately. So I thought perhaps over the course of the day the boiler was losing water (somehow, somewhere).
When it happened today, I noticed that the pump pressure gauge dropped from around 9.5 to 6 bars for twenty seconds. So, not good. I haven't done a full descale yet, as I'm going to need a large block of time to get that done.
Really it's better to do the descale, to get you to ground zero, then start working on the problems (if any remain). Descaling can even bring other problems to light, and sometimes a bit of loosened scale gets caught somewhere (tends to happen if descaling is too light touch). Don't forget to remove the autofill probe and give it a clean, simply undo the locking nut a little and slide it out, when you put it back just be very gently with the locking nut, nip it up JUST enough so the probe doesn't slide up and down when you pull it gently. If you do it too hard, you will damage the insulating sleeve .
P.S. The steam boiler is only 2 bar maximum (safety valve will let off then), this is 60 psi, you would get at least 60 probe tips in a sq inch, so less than 1lb pressure on the probe.In normal operation, at normal steam pressures probably less than 8oz of pressure pushing the probe up....which is nothing.
The "stalling" of the pump could be caused by loose scale clogging the Gicleur. That machine is in need of a full descaling. Afterwards the water level probe should be checked to be sure it is free of scale and the inside of the boiler visually inspected as well. After that you can take the necessary steps as indicated by what is found in the inspection.
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
![sheepdot: frontandback.jpg](javascript:ImagePopup("/images/59997/frontandback.jpg", 288, 829, "sheepdot: frontandback.jpg");)
= No New Posts since last visit 