Flow paths through a Faema Due water inlet valve unit

[greencardigan Senior Member Find all posts View Profile Close greencardigan]

Can anyone confirm if I've understood correctly the various flow paths through a Faema Due water inlet valve unit?

I think I need to dismantle it to check for a blockage and wanted to understand where the water is flowing.

Auto fill active (pump on and auto fill solenoid on)


Manual Fill active


Part Diagram

[260zman Member Find all posts View Profile Close 260zman]

Hey mate, I've finally had a look at your diagrams and re read your other post with what is going on.

So....the boiler filling whilst pumping out through grouphead: can mean a couple of things, 1- a cracked hx inside the boiler (pretty rare). or 2- bypassing in the water inlet valve.
I'd crack off the copper pipe feeding the hx (when shot is pulled) to see if water is flowing there and to see if boiler is still filling. if still filling, the problem is leaking inlet valve.

All symptoms u are mentioning (low flow, bypassing, noisey pump) should get solved by a thorough clean. those small copper tubes going to hx can block up very easily due to size.

good luck! (fyi I just bought a Faema Compact today which is in a "parts only" state.... watch this space!)

[MorganGT Senior Member Find all posts View Profile Close MorganGT]

Can anyone confirm if I've understood correctly the various flow paths through a Faema Due water inlet valve unit?

Yep, those are the flow paths for both manual fill and auto fill.

[260zman Member Find all posts View Profile Close 260zman]

Actually-, one more thing Brad.

On the water inlet valve, is there a small little adjuster knob? (Sorry my phone doesn't allow me to see the images). I just learnt today what that little knob does, it alters the amount off water going into the boiler during the shot. Obviously water is still being directed through the flow meters to the group head, but some must be able to get diverted via that small valve?
I haven't proved this, I just read it on a different forum so it may be incorrect.

[greencardigan Senior Member Find all posts View Profile Close greencardigan]

No, there don't think there is any adjustment knob. Not that I've noticed anyway.

When running water through the groups, I get much more flow going into the boiler instead.

I think I need to sort this out before I try running descaler through the HX. Otherwise most of the descaler will end up going into the boiler instead of the HX and group heads.

[greencardigan Senior Member Find all posts View Profile Close greencardigan]

Yep, those are the flow paths for both manual fill and auto fill.

Thanks for the confirmation

[sprezzatura Senior Member Find all posts View Profile Close sprezzatura]

Hi GC, the reason you are getting more water to the boiler when running the group is that the pump is forcing water past the two-way solenoid valve.

You will need to replace your boiler fill solenoid or take it apart and clean the internal nucleus; looking for scale, swarf or grit.

[sprezzatura Senior Member Find all posts View Profile Close sprezzatura]

Alternatively (or concurrently) water may be slipping past the manual fill for the boiler but this is unlikely compared to the boiler solenoid fail scenario which is common.

[greencardigan Senior Member Find all posts View Profile Close greencardigan]

Thanks for the info.

I tried getting the valve apart but was unsuccessful. I got the solenoid off but couldn't unscrew the valve itself.


But I think the 2-way valve could be working ok. I can't blow through it when it's off but can when it's on. It makes a good solid clunk when the solenoid turns on.

I think the manual fill button has possibly been forced in too far. The snap ring was missing. I've currently got it soaking in some citric acid to see if that helps.

[greencardigan Senior Member Find all posts View Profile Close greencardigan]

Also it's doesn't seem to be a Parker or Lucifer. Does that suggest it's not the original valve?

[sprezzatura Senior Member Find all posts View Profile Close sprezzatura]

Not really - it might've come with a M.M valve. You may have scale or a worn out seal/spring (or a 'miss-seat') in the manual fill manifold section.

[sprezzatura Senior Member Find all posts View Profile Close sprezzatura]

Put the valve in a vice and apply some firm pressure with a shifter or spanner. It'll open. Catch the nucleus as it pops out (it's spring loaded down or shut). Examine the seat area for debris. You'll understand when you open it.

[sprezzatura Senior Member Find all posts View Profile Close sprezzatura]

Have a good look at the seal and spring that blocks mains water when the manual fill is closed.

[greencardigan Senior Member Find all posts View Profile Close greencardigan]

The C-clamps on the valve unit are heavily rusted and I don't have a tool to remove them yet.

I might connect it all back up first and see how it goes after the descale I gave it.

[sprezzatura Senior Member Find all posts View Profile Close sprezzatura]

That's a good idea - Occam's Razor approach.