La Marzocco GS3: AV or MP – where the difference lies

The La Marzocco GS3 is the little sister of the commercial line, sold in two versions that differ more than their name suggests. Here's what sets the two apart – and which numbers can actually be confirmed with the manufacturer, and which can't.

AV or MP – where's the difference?

Both versions share the same build and the same pump. The difference lies in the controls.

The AV takes decisions off your hands; the MP hands them back to you. That's not a ranking. If you want a reliably identical espresso every morning, the AV serves you better; if you want to shape the shot yourself, the MP is the one.

Which boilers are inside?

The GS3 is a dual boiler. The steam boiler holds 3.5 litres – that figure is consistent across every manufacturer page. The coffee boiler is where things get messy: La Marzocco's current country sites state 1.3 litres, while the marketing center and the US site state 1.5 litres. We're not citing that number as a confirmed value. In practice, the difference barely matters anyway – what counts is that brewing and steaming run independently of each other.

Tank or direct plumbing?

The built-in tank holds 3.5 litres, with an optional direct plumbing connection. That figure comes straight from La Marzocco. A figure of 2.5 litres circulates in the trade – it contradicts the manufacturer's own information, and we go with the manufacturer.

What does the PID do?

The GS3 controls both boilers via PID, coffee and steam separately. Brew temperature is set electronically. Pre-infusion and shot volume can only be programmed on the AV. The steam wand stays cool on the outside – La Marzocco calls it 'Performance-Touch'.

Who is the GS3 for?

For a home, the GS3 is a lot of machine. It's built like commercial equipment, weighs accordingly, and needs space. In return, you get temperature stability and spare-parts support at a professional level. If you make several milk drinks a day or regularly host guests, it plays to its strengths.

If you drink a single espresso in the morning and that's it, it's simply oversized. There's no reason to buy more machine than your day calls for – the coffee doesn't get better because of it.

Frequently asked questions about the La Marzocco GS3

What's the difference between GS3 AV and GS3 MP?

The controls. The AV works electronically: a flow meter doses volumetrically, and pre-infusion can be programmed. The MP has a mechanical paddle with a cone valve, a microswitch starts the pump, you drive the pressure profile by hand, and a pressure gauge on the brew head shows you what's happening. The pump is the same on both.

Which boilers does the GS3 have?

Two. The steam boiler holds 3.5 litres – that figure is consistent across La Marzocco. For the coffee boiler, the manufacturer's own pages contradict each other: the current country sites state 1.3 litres, the marketing center and the US site state 1.5 litres. We give that number with this caveat.

Does the GS3 need a direct plumbing connection?

No. It has a built-in 3.5-litre water tank, and the direct plumbing connection is optional. Common retailer figures of 2.5 litres contradict the manufacturer's information.

What can you adjust on the PID?

The GS3 has a dual PID for the coffee and steam boilers. Pre-infusion and volumetric shot volume, however, can only be programmed on the AV – the MP has no volumetric dosing.

Does the steam wand stay cool on the outside?

Yes. La Marzocco calls them 'Performance-Touch steam wands – high-performance steam wands that stay cool'.

What portafilter diameter does the GS3 have?

58 millimetres. This figure comes from retailers; the verified manufacturer pages don't state a millimetre value.

AV or MP – which one fits me?

If you want a reproducibly identical volume and want the machine to just work in the morning, the AV is more convenient. If you want to play with pressure yourself and feel the shot, the MP is the more honest choice. Both are valid – it depends on how much you want to be involved.