This question comes up regularly and the FAQ points to several past discussions: Running an espresso machine 24/7, Electricity Usage Monitor, actual consumption (CoffeeGeek), and a poll.

My take on it from last time:

HB wrote:I can appreciate the convenience of always-on espresso machines, especially for commercial units that demand hours to stabilize. But I've still not heard any compelling evidence tying premature component failures to on/off cycling. Simply put: What components are more likely to fail if a machine is run four hours a day versus 24/7?

In past discussions, I've read the following disadvantages of on/off cycling:

• Inconvenient if one must wait, or added expense if one buys a timer; risk that machines without auto-refill with be turned on without water and burn out the heating element; risk that brew switch will be inadvertently be left in on position and burn out pump when timer starts it
• Increases scale build-up at the boiler's waterline
• "Stresses" connections of dissimilar metals (How does this manifest itself as a failure - boiler leaks? If so, from where?)
• Electronic components are subjected to changing temperatures, which increases the likelihood of them failing. The argument that failures are more common with frequently cycled computers is often cited in the same context
• Sensitive electronic components are subjected to electrical spikes when machine is turned on/off

I've read the following advantages of on/off cycling:

• Saves energy
• Increases the lifespan of gaskets
• Reduced usage decreases pressurestat's carbon buildup, which is the leading cause of failure
• Some "weaker" connections are made of nylon or plastic (tees, insulators). Exposure to less heat reduces their failure rates
• Reduced exposure to high temperatures increases the lifespan of sensitive electronic components like controllers (note: applies mostly to prosumer / semi-commercial machines; they are located outside of the case of most commercial units)

Looking at the list above, the one that sticks out for me is the pressurestat. They cost around $40-$60. If I remember correctly, that roughly equates to the added energy cost of approximately two years' 24/7 operation. It wouldn't surprise me if 24/7 operation would decrease some pressurestat's lifespan by that much (e.g., CEME, MATER).

The calculations for a cafe are a lot easier. If the cafe closes at 10pm and reopens around 6am, realistically they have little choice but to run 24/7. For those with machines that warm up in 30-60 minutes, it's an option. Is on/off cycling a more economical option? I don't know for certain, but my guess is yes, it is for most prosumer / semi-commercial units.

And Andy's insight in support of Jim's comment above:

AndyS wrote:Turning the machine off overnight will always save electricity, no matter what size it is. People who say "it takes more electricity to warm it back up than you save by turning it off" are incorrect.

There are two caveats:
1. The amount of electricity saved may be quite low, as Mike says.
2. Some people claim that certain machine components (eg, gaskets) last longer when the machine is on 24/7. (Unfortunately, many of these people are probably just repeating anecdotal evidence that does not constitute real proof. One would think that the major machine manufacturers have a lot of good data on this, though.)

With the recap out of the way, I'm surprised by the lengthy warmup times quoted earlier. When estimating warmup time for reviews, I simply attach a Scace thermofilter and log the temperature until it plateaus. The elapsed time plus a fudge factor is around 25-30 minutes for most prosumer/semi-commercial kits. The really big boiler, heavy group machines (e.g., Elektra A3, Cimbali Junior) are more than double the time of the prosumer units.

Returning to the original question specifically about heat exchanger espresso machines, I am less concerned about strict adherence to minimum warmup times for prosumer/semi-commercial Dragon HXs (*) than the more grouphead-centric Mixer/Agnostic types. For example, I would be more wary of shortening the warmup time for the Quickmill Vetrano (Mixer) than the Elektra Semiautomatica (Dragon). If you own a Dragon type and don't mind an extra warmup flush, it will shave time off the warmup with negligible impact on brew temperature stability.

(*) See this post for nomenclature.

klemenv wrote:Hi,

I am sorry for a newbie question. I got an Isomac Tea and I am drinking coffee twice per day (during week). What is it normal use, to let the machine turned on, or switch it on/off twice per day?

Hi klemenv...

I'm just going to relay a short story and the comments of the techs who worked on my machine last fall. I have an Expobar Pulsar which is about 6-7 years old now, and it was on a timer and came on at 6:30am and went off at 9pm for years. Then it went ''wonky'' and I took it to a repair shop which services most of the large in-shop rigs for major coffee bars in our area and three adjoining cities - both on site or drop-off/pick-up.

I spent about $250 having it serviced and the pstat replaced as well as the vacuum valve. While it was there they took care of the changing the pf gasket and screen too...anyway fast forward 5 months and it conked out again.

I took it back and the new tech was quite savy and in his client-list he has a caterer who uses 8 of the Pulsars for on-location espresso makers, and he takes care of them for her - so he's learned the machine very well. Her's get regular and rough treatment being hauled around their city several times weekly.

He had to replace the vacuum valve again and the pstat again...only this time he put in a different pstat (and told me he doesn't like the oem one because they go bad too quickly).

I asked about putting it back on the timer again and he suggested that is fine if I want to replace the vacuum valve yearly as well as the group gasket/screens. They had approximately 10 home machines the quality of mine or better (different brands than the Expobars) sitting in the shop, and they have discovered that many users are leaving them on all the time, and are developing regular issues after the machines are 4-6 years old.

His recommendation was turn it on 30 minutes before we need it, and turn it off till the next time...he thinks this will extend it's life considerably. He would disagree with the opinion expressed here that they are designed to be run 24/7.

So this time round, I'm turning it on/off and actually it will heat from cold to pulling first shot in under 14 minutes. I turn it on, pull a shot cold and then set the timer for 10 minutes. When the timer goes off, I test the steam wand and fill a shot glass out of the group. Then I start weighing beans for my pulls and by the time I'm ready to go, I have to surf the head down to temp (boiling steam out of the group).

If I pull shots at 9am, and I've got company coming before noon, I'll leave it on. Otherwise I turn it off and fire it up on demand. I'm going to try this for at least a year and see how it works out.

So far it's not an issue, and since I work out of our home, I can fire it up anytime I choose. Also, if someone drops in unannounced, I'm still only 15 minutes away from coffee-time, and we can chat while the machine warms up.


'

HB wrote: . . .I'm surprised by the lengthy warmup times quoted earlier.

Me too, but . . . ya never can tell. All posts should require a graphic of some sorts

I have the Vetrano for almost 4 years now and I have left it on for 24/7 for about 3 years. I find that the extra energy usage is extremely small. The convenience of having it on works for me, so it costs me 12 dollars a year in extra gaskets and perhaps 10 dollars more per year in extra energy usage (I do go away for about 5-6 weeks on business and leisure).

The Sirai pressure stat is fine (hopefully I have not jinxed myself here!) and has held up quite well.

To have hot water when your baby daughter needs milk warmed up on demand is priceless and has saved me from using my microwave literally dozens of time to heat up the water.

Oh yeah and on those days when I wake up a little late and would not have time to wait for the machine to warm up to make a double espresso before work, having the machine on has been a lifesaver!

My Domobar Super (VBM) is in my office. It gets turned on in the morning and off when I leave for home. It takes about 45min to heat before I will try a shot I like to give it an hour or more. On my Elektra A3 (home) it runs 24/7 with the exception of the super hot summer days. Then I will turn it off during the day. I will switch it on before I go to bed for my morning cup then off. My drive is about an hour so I will call the wife and have her turn it on when I leave work. By the time I am ready for a shot it has been an hour and a half, but for 90+% of its life, it runs 24/7.

Say what you will about the environment, I try to do my share. But when I get off the deck at eleven PM, drive home for a half-hour, make a meal, take a shower, set out clothes and kit for the next day, climb into bed at about midnight-thirty, and to sleep around one AM, I'd be willing to burn baby kittens for the privilege of pulling a doppio within minutes of the alarm going off at five-thirty in the morning. On the second day of that schedule, I'd gladly line up family members if I'd run out of kittens.

Other than a recent cupping, the last time I left the house without at lest one pull was under the orders of my physician.

Suggest family member first, then kittens. Less remorse.

I have my Andreja on a timer to power on in the morning early enough to be ready by the time we wake up. I can usually hear the damn thing start from our upstairs bedroom.

I have the timer set to turn off every 2.5 hours, but I can turn it on anytime to brew. I just don't feel right leaving it on the entire day and hear the Sirai click all day long since I work from home.

I think I will start to leave it on during the day and turn it off in the late afternoon. It's nice to have a cappa while on a long conference call.

My Vetrano's on a timer, set to start about an hour before I usually have my first cup. Now that I work out of a home office it stays on till about eight at night (occasionally later if I think I might want coffee later). When I used to work outside of the house, it started the same time, but I set it to go off till about an hour before I'd come home, then off again at eight.

So, the bottom line, is my preference is pretty much for convenience. I have not noticed an issue with gaskets drying out prematurely.