Why Thermoblock Machines Warm Up Quickly

The wait is short because there's little to heat. A boiler has to warm a whole vessel of water. A thermoblock only has to warm a block of metal and the water that passes through it.

What you'll need

• Your manual, open at the page on switching on and warming up.
• A clean water tank filled as the manual says.
• A cup, if your manual describes a pre-warm step.

Why it's quick

One guide calls the relatively short heat-up time the major advantage over boiler machines. It adds that the heating element heats up quickly.¹

Wikipedia's page on tankless heaters points to a related benefit. With no hot water tank, there are no standby energy losses. That's about household heaters, not espresso machines, so check your manual for how yours behaves when idle.²

What a maker's manual says

The instruction text for one thermoblock machine gives the initial heat-up as under one minute at normal room temperature. Once the thermoblock is heated, the green ready light turns on.³

Treat that as one model's figure. Another machine could be faster or slower. Your manual is the only source for your own heat-up time.

A pre-warm routine from the manual

The same manual says to pre-warm the internal parts and the cups before making espresso. It says this short procedure will add 10° to 15° F to the first cup.³

Here's the routine, paraphrased from that manual:

1. Set the control dial to its middle (standby) position, then switch the machine on.
2. Fill the tank with fresh, cold water.
3. Put the filter sieve in the portafilter with no coffee in it, and lock the portafilter in place.
4. Place one or two cups under it and wait for the ready light.
5. Turn the dial to the brew position so hot water runs into the cups.
6. Turn the dial back to the middle position to stop the flow, then empty the cups.

³

The manual warns never to leave the machine unattended during brewing or steaming. Follow the manual for your own model, since the steps and settings will differ.³

Warming with a few blank shots

A different guide describes a similar idea. The block can be brought to temperature relatively quickly through a few shots without coffee loaded.¹

Whether that suits your machine is a question for its maker.

What "ready" means

The ready light means the heater has reached its working temperature. It doesn't mean the cups, the portafilter and the rest of the metal are warm too. That's why a pre-warm step exists at all.³

Short wait, then. Not zero.

If it's slow

A machine that takes much longer than its manual says should go back to the maker or a qualified technician. Don't open the case yourself. The steam switching page covers a different kind of wait.