I have recently bought a Gaggia New Baby. At first, I assumed that it would have to be backflushed, since it has a 3-way valve, and since many people backflush it. But today, I discovered that it's a controversial issue. It's controversial for a few reasons, but what I'm most confused about just has to do with the valve.

There's this post that says that, since Gaggia has the 3-way valve between the boiler and the pump, instead of between the boiler and the group, there's no point in backflushing.

Here's a parts diagram for the New Baby. It seems to me that the 3-way is between the boiler and the pump, as that post says, but I'm not sure if I'm reading it right. But! This other post says the 3-way valve is still in the usual place, between the boiler and the group, even though things are arranged a little bit differently. But he's talking about a different model - does this apply to the New Baby as well? I don't see it from the parts diagram (which means little since I'm having difficulty reading it) and I'm not at a point yet where I want to try disassembling it to see if that would help me understand it. So, if anyone can help me: where is the 3-way valve on the New Baby?

If the post with the diagram applies to the New Baby, then it makes sense to backflush it, as far as I can tell. If not, then I have more questions... like what keeps water from coming out of the group head when the machine is off, and what's the point of having a 3-way valve before the boiler rather than after.

Gaggia really messed up with their naming and changing.
Early Babies definitely had 3-way solenoids, but somewhere along they line they got left off.

Here's how to figure out which you have:
is there a release of water into the drip tray when the shot ends? (if yes, you have a 3-ay)
Do you have a group valve? (if yes, you do not have a 3-way).

Oh, if that really is a diagram of your machine, then #29 is your 3-way.

The solenoid resides behind the boiler. The plumbing is between the boiler and the grouphead. I'm not an engineer, but if coffee goes through it just the same, then I don't know why you wouldn't want to backflush it regardless of where it is physically located.

I have release of water into the drip tray, so I know there's a 3-way valve somewhere. My machine is this version, which looks different from the one in the parts diagram, but Parts Guru calls them by the same name and has one parts diagrams for both. Since I've no better option, let's assume it's correct.

One thing that I'm confused about is how things connect. The outlet hose from the 3-way (33), where does it go? Does it go to 15? The parts diagram says it's a valve - is it another component of the solenoid, or something else? I'm guessing the OPV is 39, so I don't know what else 15 could be. Anyway, if the outlet from the 3-way goes to 15, does that connect to copper pipe (25) which goes to the group, through the boiler for heat-exchanger action? That would make sense to me, but idk if it's correct.

HoldTheOnions wrote:I'm not an engineer, but if coffee goes through it just the same, then I don't know why you wouldn't want to backflush it regardless of where it is physically located.

Because there's no consensus on whether or not backflushing is a good idea for Gaggias, and it's an opportunity to get to know the machine.

If it has a solenoid valve, which you seem quite sure it does, it should be backflushed.

ieowfksdn wrote: One thing that I'm confused about is how things connect. The outlet hose from the 3-way (33), where does it go?

It goes to the drip tray.

ieowfksdn wrote:Does it go to 15? The parts diagram says it's a valve - is it another component of the solenoid, or something else?

Not even close. 15 is the steam valve.

ieowfksdn wrote: I'm guessing the OPV is 39,

correct

ieowfksdn wrote: Anyway, if the outlet from the 3-way goes to 15, does that connect to copper pipe (25) which goes to the group, through the boiler for heat-exchanger action?
That would make sense to me, but idk if it's correct.

It's not

Ah, right, I wasn't thinking about that
So how does it get from 29 to the group?

At the inlets where #30 indicates a gasket

Yes, but where does it go? Is there a pipe or some other connection that goes through the boiler from one of those gaskets to 25?

No pipe. There is a channel molded into the boiler.
See if this picture helps. It's not the same boiler (this is from the Old White Coffee which is the predecessor to the Classic) but the path from the solenoid to the boiler is clear.

Thank you.