I have a Sama Export that has been in daily use since I rebuilt it last fall. At home, I had it on a timer so that it would be up to temp when I woke up, mostly out of sheer laziness because it was always very quick to come up to temp - maybe 5 -7 minutes for a full boiler. I decided to bring it into work a couple of days ago so I would have a machine with steam for milk drinks, and now it takes 45 minutes to come up to temp. Before I moved it, the machine would literally roar to life when I turned it on. Now it is completely silent and heats yup very slowly. It does come up to temp, and the pStat eventually switches off, but it's very odd that this change occured.
It is a 110v element. The machine is clearly getting power. I filled and emptied the boiler a few times last night and there was a good amount of scale coming out (I descaled a few weeks ago and filled and emptied 4 - 5 times, but I guess I didn't get everything out). I took the tube that goes from the boiler to the pStat off and it is completely clear of scale or other debris.
My main concern is safety - if the pStat is clogged, is there a danger of the pressure going to 3 bar or something like that? Of course, it's also much more convenient to not have to wait 45 minutes to come to temp or always have to start with putting just-boiled water into the boiler.
Any ideas on troubleshooting this? Could scale have dislodged from somewhere and gotten into the pStat itself when I moved it, clogging it? If so, might that explain this new 'behavior'? Could one post on the element not be getting power - the wire got loose or was otherwise compromised? What is so confusing to me is the change from an easily discernable 'whoosh' when powering it on before followed by a rapid heatup, to the state of things now, where it is utterly silent when I power it on and it heats up slowly.
I'm no expert on electricity but it seems to me from my Chief Engineer days that if things are going wrong all of a sudden you should suspect the last thing you did. How hard is it to take the Sama back home and plug it in? That will identify where the problem is, outside the machine i.e. lousy power, or inside the machine. Maybe someone will correct me but my understanding of the pStat is it is a pressure activated switch with two states, on or off. If true I don't see how that would affect your heat up rate. I really suspect external to the machine. Can you get a voltage tester and see what the voltage is at your machine?
SStones Senior Member Joined: 24 Nov 2012 Posts: 482 Location: Canada Expertise: Professional
Espresso: Giga 5, ECM Giotto, Rocket... Grinder: Anfim Milano-Best Vac Pot: No :( Drip: Some $30 thing from Walmart Roaster: I buy pre-roasted.
Posted Sat Apr 27, 2013, 3:57pm Subject: Re: Sama Export heating issue
Everything Flathead is saying is true, but from experience I am going to through out the guess that the element has just died OR that the powerswitch is building up a lot of carbon and causing resistamce. Do you have an ohm-meter? Can you check the resistance across the element? I am not so familiar with the Sama Ex, but a single-element 110V machine's element is going to be between 10 and 17 ohms resistance.
Does the switch feel warm within three minutes of turning it on? Switches blocked by carbon build up will often warm up (They're a source of voltage-drop, like a heating element).
If the element is cracked (Perhaps it happened in the move), water will get inside and soak through the silicate insulation. The wire inside that makes the heat will immediately short to ground through the wetness and burn itself out in a spot. The wire will still have a path to ground, through the wet insulation inside the exterior shield of the element, and therefore will still heat the machine slowly, like a little 60 watt element.
Hope this helps. And if the element is blown/cracked, your only fix is to replace the entire element. I don't know where you'd get it, but my little google search was short.
grogstah Senior Member Joined: 26 Oct 2010 Posts: 11 Location: Seattle Expertise: Just starting
Espresso: La Pavoni Pre-Mil, La...
Posted Wed May 1, 2013, 8:04am Subject: Re: Sama Export heating issue
SStones, you were spot on. The element (likely the original, so around 40 years old) had somehow become compromised and had actually expanded slightly in size. Check with an ohm-meter confirmed that the element was on its last legs. Replaced the element (and the original pStat while I was at it) and all is functioning again.
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