Heat up times 15 vs 20 amps

#1: Post by **kjrs85** » August 26th, 2021, 9:22 pm

Hey there!

I'm racking my brain about this 15 vs 20 amp debate.
This is what I've gathered from the forums:

-In 20 amp mode both boilers can heat at the same time, but no one cares unless your making 100 lattes in a row!

HOWEVER! My big question is HEAT UP TIME? No one seems to have talked about this???

Can anyone verify if the heat up times are faster in e61 machines that run on 20 amps vs 15?
I know their group stilll needs ample time to heat up, but is there any difference overall?

I'm curious because I'm hesitating between the Lelit Bianca (which apparently has a fast heat up time) vs a 20 amp machine like the Vetrano.

If anyone can chime in and let me know that would be great!

Thanks!

#2: Post by **Jeff** » August 26th, 2021, 9:36 pm

Marginal, if any difference. The specific machines probably makes more of a difference.

If the main brew boiler has the same Wattage heater in the same machine. No difference. Even if it were slightly more powerful, most of the time is the group coming to thermal equilibrium with the boiler. As I vaguely recall, the brew boiler comes up to temperature in on the order of 10 minutes. You might trim a couple minutes off the typical 30-45 minutes for an E61 to be ready.

August 27th, 2021, 5:06 am

Welcome to HB Kyle.

I agree with Jeff.

Brew boiler has priority on heating up. You could trim some warm up time if you're in a hurry by doing a flush of the brew group. After you own your machine this issue won't make a difference especially if you put it on a programmable timer.

You might do better determining which machine to purchase based on other features.

Be sure to budget for a proper non-scaling water system. While Montreal water tastes great - it will cause scaling issues!

#4: Post by **PeetsFan** » August 27th, 2021, 9:42 am

I ran my machine in 15A mode and it was much slower to heat up. But my machine has a wake timer, so it doesn't really matter.

I use 20A mode and never tripped a breaker. It can make reheating faster if both boilers have refilled.

August 27th, 2021, 10:15 am

PeetsFan wrote:I use 20A mode and never tripped a breaker.

That might be so but it should be noted that a 15amp programmable timer in conjunction with a machine in 20amp mode on a 20amp dedicated circuit might sooner than later burn itself out.

#6: Post by **Almico** » August 27th, 2021, 10:30 am

I think the time the group needs to come to temperature stability offsets the differential in amperage. My ECM Giotto needed 20 minutes to get the boiler to temp, but 1-1/2 to be ready to pull a good shot.

August 27th, 2021, 10:55 am

1 1/2 hours? How can it take so long? Can't you just pull a few dummy shots to bring the group head up to temp?

#8: Post by **Jeff** » August 27th, 2021, 11:02 am

You need to heat the group head all the way through to get repeatable temperature. There's a lot of brass there and the thermosiphon intentionally doesn't pump a lot of heat into it for an HX. I'm not sure how the DBs run restrictors. On both, the closer to boiler/HX temperature you get, the slower the heat transfer.

#9: Post by **cafeIKE** » August 27th, 2021, 11:14 am

That might be so but it should be noted that a 15amp programmable timer in conjunction with a machine in 20amp mode on a 20amp dedicated circuit might sooner than later burn itself out.

Connect Sense 20A Programmable WiFi socket @ Amazon

#10: Post by **PeetsFan** » August 27th, 2021, 11:17 am

Jeff wrote:You need to heat the group head all the way through to get repeatable temperature. There's a lot of brass there and the thermosiphon intentionally doesn't pump a lot of heat into it for an HX. I'm not sure how the DBs run restrictors. On both, the closer to boiler/HX temperature you get, the slower the heat transfer.

How do you measure temperature to ensure that the group head is fully heated? I tried one of those IR thermometers, with the little laser dot, but I don't think it measures correctly at all against the polished stainless.

By the way... I'm not trying to challenge you or question you. I always always want to learn more. My machine has a timer function, but if I should make sure it's running for an hour before I pull my first shot, that's not a big deal.