skithebird Senior Member Joined: 1 Jan 1970 Posts: 100 Location: Evanston Expertise: I live coffee
Espresso: Elektra Micro Casa... Grinder: Rancilio Rocky, Mazer Mini Vac Pot: NA Drip: French Press Roaster: NA
Posted Mon Jul 24, 2006, 5:56am Subject: Continuous Machine Operation or Power Switching for Longest Heater Life?
If there's been a thread on this topic, I haven't seen it.
What is common practice in the community, and the thinking behind it, for leaving our machines on 24/7, versus only when we're getting ready to pull shots? Does anyone use a programmable power timer that works well? I've assumed it's alot tougher on a machine's electronics, including the heater, to be cycled up and down on a twice daily basis, unless it's done throughtfully. I leave my computers and audio components on continuously without any apparent lifetime problems.
As with most machines, my Elektra Microcasa Semiautomaticas take 2-3 hours to reach their useful steady state, and overnight is even better. Having to remember to pre-think a proper warm-up time adds to inconveninece, and practically eliminates spontaneity.
Why do I ask?
Well, about a month ago, my 3-year old SA's heater died, seemingly from an insufficiently decalcified valve that malfunctioned, causing an overnight water leak, and that, heater burnout. Bummer.
Then last week, my new 3 week old (repaired older machine heading for the office), had its own melt-down. What's this? Infant mortality? A reliability problem? 3 weeks of calcium build-up? Or the standard risk of 24/7 usage?
At 2 AM, my wife heard a loud hissing noise that sounded like a street cleaner or worse. She said she thought the loudness was increasing rapidly, and investigating the source, found it to be the SA. Before she could act, sudden silence. The machine appeared dead. In the morning, I determined that although the pump was still working, the heater had blown.
This was a 3 week old machine using bottled water chosen for its low calcium, with a fastidiously full water tank.
In this case, the vendor, one of the best out there, overnighted a brand new machine, and an RMA for the blown one.
The vendor said, however, that he doesn't recommend leaving any of the "home" machines on all the time, and suggested I add a programmable switching system instead. He told me about one machine's heater that self-destructed in a week-and-a-half. Good story, inconclusive arguement for switching. I continue to worry that unless power-switching components are very well rectified, the switching transients will do more long term damage than 24/7 operation.
Has anyone else worried about this problem, and taken the programmable power switching step? If so, what are your recommendations?
Or do most of you just continue to risk a sudden blow out as I have?
Fire hazard - I would say no, but grew up learning anything that gets hot should be supervised (irons, ovens).
Bacterial growth - germs like warm places.
Wear - Ted sums it up well:
"Mean time between failures (MTBF) doesn't mean much in some circumstances. Computer hard drives use/used ball bearings with very consistent MTBF levels having to do with metal fatigue after >10,000 hours. If the computer is on 24/7 the 10k hour mark will simply come along sooner. More pointed example is the cheesy fans that predictably go bad very quickly on a computer that's always on, and rarely malfunction on grandpa's Dell.
I guess my point above is that the benefits of running equipment 24/7 need to be weighed against the negatives. On the Isomac, the pressurestat contacts probably have a finite life based on the number of cycles (+/- 1400 / 24hr. of operation), as do the boiler and other pressurized components. Cutting the number of cycles on the boiler pressure adds cycles to the pressurestat and hours to the heat on the natural rubber o-rings and plastic Y's. Help one thing, hurt another.
We're making the same bet, just on different components."
Terry of espressoParts.com presents another point of view:
"I'd be interested in hearing non-anecdotal evidence that confirms or refutes the assertion that 24/7 uptime affects MTBF rates. For what it's worth, in the perenial debate among computer hardware engineers, the majority leans toward "turn it off at the end of the day" and they deride those who say otherwise as recounting data from the early 1970s. As I recall the details of one story, IBM once issued a warning to owners of a certain 3270 display model ("green screen" as shown below), telling them that daily on/off cycles would dramatically affect the MTBF rate. Customers diligently followed IBM's advice, and screen burn-in was born -- and spawned an entire micro-industry of "screen savers" years later. Ironically, IBM manufacturing quickly corrected the fault in the 3270 line. More than two decades later, many customers and engineers insist the displays must be left on.
Hence why this discussion provokes such a strong sense of déjà-vu in me. I've read similar discussions on cars ("Should I leave my car running for 15 minutes while I wait for my wife, or restart it?"). But I digress."
I think the short answer is nobody has any hard data; maybe the manufacturers do, but there's little motivation for them to share it publicly.
Mista_T Senior Member Joined: 4 Jan 2004 Posts: 99 Location: New Zealand Expertise: I live coffee
Espresso: Elektra MC SA, Carimali Uno Grinder: Mazzer SJ, Anfim Milano Vac Pot: Bodum Santos Roaster: iRoast
Posted Mon Jul 24, 2006, 2:13pm Subject: Re: Continuous Machine Operation or Power Switching for Longest Heater Life?
skithebird Said:
...my Elektra Microcasa Semiautomaticas take 2-3 hours to reach their useful steady state, and overnight is even better. Having to remember to pre-think a proper warm-up time adds to inconveninece, and practically eliminates spontaneity.
I used a timer to turn my machine on an hour or so before we got up in the morning. I found this was an ample length of time to heat the relevant parts of the MC SA (i.e. group head, PF) to a working temp. I would dispute that it needs to warm up overnight. I agree that having to wait for a machine to heat up eliminates spontaneity, which is partly why I tend to leave the machine on whenever I am at home, including all day at the weekend.
In the two years I have had the Elektra, it has worked flawlessly following the above routine.
skithebird Said:
The machine appeared dead. In the morning, I determined that although the pump was still working, the heater had blown.
Are you aware the Elektra has a thermal cutout switch on the bottom of the boiler? I faced similar symptoms after leaving the steam valve cracked open following a cleaning session one evening. I awoke to a steamed up kitchen and a partially dead Elektra. Fixing the machine was a simple as pushing in a circuit breaker, although I only discovered this having spent an espresso-less week looking for a new element.
itinerant Senior Member Joined: 1 Sep 2005 Posts: 899 Location: Vancouver Expertise: I live coffee
Posted Mon Jul 24, 2006, 5:27pm Subject: Re: Continuous Machine Operation or Power Switching for Longest Heater Life?
You will see in the threads that Dan references, there isn't much of a consensus. I think that it would be fair to say that the majority seem to feel that leaving machinery on 24/7 will probably extend it's lifespan due to reduced thermal cycling. Support for this position has generally been extrapolated from machinery such as internal combustion engines and hard drives, where there is some real data to support the position. Direct evidence is not much more than anedoctal for espresso machines per se.
It's interesting to see that the OP & at one of the referenced threads mentions that switching spikes may be inducing some electronics package failures. With that in mind, I think that I will take a few minutes this weekend to capture a typical transient with a scope. And add a few clamping diodes & filter caps to the low voltage power rail. The OP might consider the same, as he appears qualified to wield a soldering iron.
But it's truly a tossup when you ask people the bottom line.. do you leave your machine on 24/7? There is the above lifespan argument, convenience & possibly drink consistency arguing for. And cost, undesired summer heat load (heating up your kitchen), the possible risk of water or fire damage & general energy conservation issues arguing against.
All things considered, I do leave my Cimbali's on 24/7. It is worth it (to me) just for the temperature stability (drink quality) & convenience. With well-maintained commercial equipment, I don't feel that there is an undue risk or water or fire damage. Still, after installing a PID, I set the pressurestat to act as a high level cutout. Also my home alarm would cut the machine power & water supply if a water leak or smoke was detected. And I insulated the boilers to minimize heat load & electrical consumption. But of course, many argue for turning a machine off at night. If you decide to turn yours off at night, you might consider an appliance timer to automate the task which allows your machine sufficient time to warm up before you plan to use it.
rstevens Senior Member Joined: 17 May 2006 Posts: 23 Location: Albany, NY Expertise: I love coffee
Espresso: La Spaziale S1 Vivaldi II Grinder: Mazzer Mini-E Drip: nope- French press Roaster: Behmor 1600
Posted Mon Jul 24, 2006, 5:33pm Subject: Re: Continuous Machine Operation or Power Switching for Longest Heater Life?
I can't comment on the MTBF or other technical issues but I recently purchased a Quick Mill Vetrano and it seemed crazy to leave the thing run all day and night...especially in July. I found a great outdoor class digital timer at Home Depot. This is nice as it handles the big vetrano with ease and is very easy to set thanks to the digital interface. This model also allows multiple on/off settings for weekday and weekend times.
rbh1515 Senior Member Joined: 15 Feb 2003 Posts: 1,059 Location: Milwaukee Expertise: I love coffee
Posted Tue Jul 25, 2006, 11:57am Subject: Re: Continuous Machine Operation or Power Switching for Longest Heater Life?
I've had expresso machines for a number of years and have tried many different ways. 1)Turn on before use and wait to heat up--that's what I'm doing now, especially since its Summer and with the AC running I try not to heat up the inside of the house. It is a bit of a pain in the morning. 2)Timer--I used to use one until its internals got fried. It was rated high enough for my machine. Not sure why it fried. I did have one mishap with the timer with one of my machines. I was cleaning the outside of my machine one evening while it was off. It had a lever to activate the pump. I raised the lever to clean the ss under the lever and forgot to lower the lever. In the morning I had water all over and a burned out pump and found out that the low water senser on the reservoir did not work. 3)On all the time. I used to do this all the time and never had a problem. It just wastes a lot of energy and heats up my house. Bottom line: I worry a bit having a machine on, unattended, with very hot water at a high pressure. At this point in time, I feel best turning on the machine before use. Rob
CoffeePhilter Senior Member Joined: 9 Feb 2005 Posts: 621 Location: St. Albert, Alberta Expertise: Professional
Espresso: Bricoletta Grinder: Macap
Posted Tue Jul 25, 2006, 2:52pm Subject: Re: Continuous Machine Operation or Power Switching for Longest Heater Life?
I ran my Bricoletta continuosly when I first got it for a number of months, and while very convenient, I noticed a significant jump in our electrical bill cost. I insulated the boiler as soon as I got it as well, so there isn't much else I can do to reduce the power consumption.
When I started cycling it a couple times a day (on/off in the AM and on/off in the late/afternoon/evening) I noticed the electric bill immediately dropped about $20 a month.
Bottom line, even if the machine does wear out 5 years sooner than if it was on continuously, the cost savings in electricity would allow me to either repair it or simply purchase a brand new $1250 machine every 5 years. No brainer for me.
Side question....anyone actually measured the operating cost of the machine using a "real" power consuption meter?
skithebird Senior Member Joined: 1 Jan 1970 Posts: 100 Location: Evanston Expertise: I live coffee
Espresso: Elektra Micro Casa... Grinder: Rancilio Rocky, Mazer Mini Vac Pot: NA Drip: French Press Roaster: NA
Posted Tue Jul 25, 2006, 8:27pm Subject: Re: Continuous Machine Operation or Power Switching for Longest Heater Life?
First, I’d like to thank everyone for their useful input!
I must say, despite the great review of previous threads on this point from Dan (Thanks, Dan!), and all these new perspectives, I’m still unsure what to do.
No doubt leaving on an 800W appliance 24/7 has significant energy conservation and energy cost implications.
Those important concerns aside, and only worrying through the inconvenience of sending a machine off for repair, then having it unavailable for what can become 3-4 weeks or more, has motivated this discussion. 4 weeks without a ristretto or two a day? Impossible.
A number of people have reported excellent results running their Elektra’s 24/7 for years. One person told me a while ago his had been going for 5 years 24/7 without seeing a repair shop.
Yet the vendor in this case, has reported anecdotes about some people whose experience has been far shorter, even as short as a week-and-a-half!
Mista_T mentioned there's a cutout switch on the bottom of the breaker. Good to know! I found out about it this time though, but unfortunately it wasn’t the problem. The vendor walked me through various continuity tests by phone, until we concluded the heater had indeed burned out.
Rstevens was kind enough to mention his Home Depot switch purchase. I wandered the Home Depot website and think I see the one he’s using. I also Googled the general subject, and found nothing much better. If I have the right one at Home Depot, it’s priced at under $30 and used mainly for controlling home lighting as a security measure. I’m wondering how something so simple can possibly provides clean enough power on switching, free from the transients and switching peaks that we know are bad for heating elements.
Then I’m also wondering if the combination of a simple programmable switch with a beefy Variac would be safer practice. The Variac should act as a powerful buffer to ac input noise and switching spikes. Anyone agree?
Rob (rbh1515) tells a sad tale where all the best intensions of using a power switch still led to disaster.
Making this operating decision more confusing, the vendor has warned me that when a machine is operated 24/7 one risks much more rapid calcium build-up. Is this so? Decalcification is already quite a chore. If the frequency of a sticky valve, leading to catastrophic water leakage, and subsequent heater burnout, is a serious risk, wouldn’t that in and of itself argue for some kind of programmable switching? Or do those problems correlate more with water quality than with continuous operation?
Perhaps this is just one of those issues where there is so sure answer?
mcKoffee Senior Member Joined: 29 Dec 2001 Posts: 750 Location: Vancouver WA USA Expertise: I live coffee
Espresso: Bricoletta, Audrey, LM 3AV... Grinder: Mazzer Major,SJ, Rocky,... Vac Pot: Gold Royal Balance Drip: When it rains...Moka, FPs Roaster: USRC3k,CCR HT, Behmor, Cafe...
Posted Tue Jul 25, 2006, 9:20pm Subject: Re: Continuous Machine Operation or Power Switching for Longest Heater Life?
CoffeePhilter Said:
I ran my Bricoletta continuosly when I first got it for a number of months, and while very convenient, I noticed a significant jump in our electrical bill cost. I insulated the boiler as soon as I got it as well, so there isn't much else I can do to reduce the power consumption.
When I started cycling it a couple times a day (on/off in the AM and on/off in the late/afternoon/evening) I noticed the electric bill immediately dropped about $20 a month.
Bottom line, even if the machine does wear out 5 years sooner than if it was on continuously, the cost savings in electricity would allow me to either repair it or simply purchase a brand new $1250 machine every 5 years. No brainer for me.
Side question....anyone actually measured the operating cost of the machine using a "real" power consuption meter?
Haven't run a 'real' consumption meter but have done the math. My insulated Bric' is heater on ~3% duty cycle idle. 3% of 1800w heater equivalent to 54w on all the time. Our rates are $0.0763 1kw/hr which works out to $0.059 per hr idle or $1.41 per 24hrs = $42.38 thirty days 24/7. During warm up duty cycle is more frequent but haven't sat their for an hour and counted. (and won't!) Your $20 monthly savings seems realistic.
FWIW I've been running my Bric' on this $10 control module for months. You of course need control unit, which can even be a computer.
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