Leave your La Marzocco GS/3 on

#1: Post by **malachi** » June 15th, 2010, 12:12 pm

Had an interesting talk with someone from LM yesterday.

Based on this conversation, I'd suggest folks who own a GS3 leave their machines on (rather than running them on a timer - either internal or external). Sounds like not only does this not use more energy, but it seems to help with mineral precipitation issues (though, of course, if you own an expensive machine like a GS3 and you're not running a real filtration scale reduction system then you're kind of crazy as the help might only be delaying in nature).

#2: Post by HB » June 15th, 2010, 12:16 pm

malachi wrote:Sounds like not only does this not use more energy...

I had no idea La Marzocco had incorporated perpetual energy into their design!

Seriously, rather than rehash this tired argument, would someone with a GS/3 and a Kill-a-Watt please measure? Perhaps JonR10 or Nicholas will indulge my request?

#3: Post by HB » June 15th, 2010, 12:21 pm

malachi wrote:...it seems to help with mineral precipitation issues

This is noted as bullet #2 in Should an HX espresso machine be turned on/off, excerpted for reference:

HB wrote: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:

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 the 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.)

#4: Post by **Marshall** » June 15th, 2010, 1:26 pm

Talked to my wife, the water treatment chemist (retired). Calcium carbonate, the major (but not sole) scale producer, precipitates out scale more quickly, not less quickly, at higher temperatures. So, this made no sense to her, but she's open to further explanation.

#5: Post by **Peppersass** » June 15th, 2010, 1:44 pm

HB wrote:I had no idea La Marzocco had incorporated perpetual energy into their design!

Seriously, rather than rehash this tired argument, would someone with a GS/3 and a Kill-a-Watt please measure? Perhaps JonR10 or Nicholas will indulge my request?

I'm skeptical, too. I have the equipment and will do some tests.

First I'll run the machine for 24 hours using my normal timing cycle, which is to turn the machine on at 6:00 AM and turn it off at 10:00 PM. This 2/3-on, 1/3-off cycle should be more favorable to LM's theory than just running the machine four hours a day (no way that's going to use more electricity than running the machine for an extra 20 hours!) I'll record the consumption after 24 hours, then I'll run the machine for a straight 24-hours and record the consumption. I will endeavor to make the same number of drinks in both tests.

Finally, I'll repeat the test using the Half heating cycle option. In a previous, less rigorous test I found the machine uses significantly less electricity in Half mode, with no adverse effects on coffee or steam performance (for the low duty cycle I normally use -- I'd use Full for a party.) I think Nicholas disputed that this is possible, seeing as how the same amount of electricity is required to keep the boilers at the programmed temperature settings.

#6: Post by HB » June 15th, 2010, 2:16 pm

Thanks Dick for offering to provide hard data. As for this...

Peppersass wrote:Finally, I'll repeat the test using the Half heating cycle option.

How does this work? Run the steam boiler at a lower temperature (similar to the Techno's economy mode)?

#7: Post by **tekomino** » June 15th, 2010, 2:33 pm

HB wrote:How does this work?

It powers only one boiler at a time. Default mode sends power to both boilers at the same time and draws about 1600 watts on full load.

#8: Post by **JonR10** » June 15th, 2010, 5:01 pm

Marshall wrote:Talked to my wife, the water treatment chemist (retired). Calcium carbonate, the major (but not sole) scale producer, precipitates out scale more quickly, not less quickly, at higher temperatures. So, this made no sense to her, but she's open to further explanation.

It has been my impression that repeated heating and cooling cycles would promote precipitation, particularly at the junction of dissimilar metals but since I can't remember why I'll only post the suggestion that this may be a possibility.

I leave my machine on now, because when I was using the timer it created issued with the steam boiler vacuum breaker occasionally sticking. It was developing some deposits in it, even though I use soft spring water (measures 8-10 ppm TDS).

HB wrote:Perhaps JonR10 or Nicholas will indulge my request?

I'm willing, but I loaned my kill-a-watt out months ago so I'll see if I can get it back....

#9: Post by **Peppersass** » June 15th, 2010, 11:46 pm

JonR10 wrote:I leave my machine on now, because when I was using the timer it created issued with the steam boiler vacuum breaker occasionally sticking. It was developing some deposits in it, even though I use soft spring water (measures 8-10 ppm TDS).

Ah. I had that problem, too, after about six months of using cation-softened water. The top of the valve is exposed to air, so the water that gathers on it during the steam boiler warmup cycle evaporates and leaves behind whatever minerals are disolved in the water. They, in turn, can make the valve stick in the open position. I had to take my valve apart and soak the pieces in vinegar to get rid of the deposits.

We have very hard water (about 150 ppm) with high alkalinity (also about 150 ppm.) The cation softener gets rid of the hardness, and the alkalinity won't precipitate out, but it does get left behind when the water dries up. This is a good reason not to drain the machine when not in use during vacations, etc. I think that's fine for a few weeks or maybe even a few months, but long-terms storage would be another issue.

The word is that the breaker valve problem will recur about every six months. It never occured to me to just leave the machine on. Duh.

Well, the tests I'm running will at least put a cost on that.

#10: Post by **Peppersass** » June 15th, 2010, 11:56 pm

tekomino wrote:It powers only one boiler at a time. Default mode sends power to both boilers at the same time and draws about 1600 watts on full load.

Essentially correct, but the brew boiler always gets priority. That maintains the integrity of the brew temperature stability for which the GS/3 is famous.

The machine is such a powerful steamer that I haven't had any problems steaming on the HALF setting. I think the recovery time after steaming or running hot water is a little longer, but I haven't quantified it. If I was making a lot of milk drinks for a party I would simply flip the machine into FULL mode.

BTW, my Kill-O-Watt beeps when the machine is set to FULL mode and I turn on the brew switch. Evidently, the combined amperage of the motor and both heaters is pushing 15A (I assume that's what the Killl-O-Watt is set to.) However, the circuit breaker has never tripped, so the electronics in the Kill-O-Watt must be more sensitive than the mechanical breaker. Nonetheless, I need to consider adding a dedicated 20A circuit for the GS/3.