VB from LFGSS kindly supplied me with his faulty Gaggia Baby Class coffee machine.

No water was coming from the group head(?) although everything else was working as expected. Forum chatter about this machine indicated it either needed a descale or it needed a new pump.

I read Robert Harmon’s information about Gaggia maintenance, bought my self a syringe from Boots and some citric acid-based descaler from Waitrose then descaled and cleaned the unit as much as I could with no change. Using the syringe I made sure the pump was correctly primed. No change.

So, I assumed it was a faulty pump and before Christmas I ordered a replacement Gaggia pump from Happy Donkey: happydonkey.co.uk – gaggia spares

It cost ?34.88 including postage.

Update:

I’ve worked out how to pull the unit apart and found the pump. It was a complete bitch to replace this pump!

With the new pump fitted I tested the unit and exactly the same thing happened – no water came out of the head but the steam wand still worked. DAMN!!! It wasn’t the pump. Waste of time and money.. but now I’m even more determined to fix the unit!

Update:

I’ve now stripped the Gaggia right down and think I’ve found a blockage.. the copper tube inside the boiler, that dumps into the head, doesn’t let air through. I can’t see any valving between the top of the tube and the head (under the screen) so methinks this is the blocked area. Now to try and clean it out..

Update:

Right.. this machine is in about 400 pieces.. there weren’t even that many in the Gaggia schematics. 😉

Anyway, it’s not the boiler’s copper pipe->grouphead arrangement, no, it’s more complex than that. The blockage appears to be in some kind of blue electronic valve thing which controls the water FROM the boiler TO the head and from the boiler to the drain pipe. Is this the OVP? The Over Pressure Valve? Help!

It looks like Part 27 – “DM1645/001 – solenoid valve” in here:

partsguru.com – ER0182_Rev01.pdf

I’ve found spares here.. “DM1645/002 or 1152/002 Elektrovalve 120V”

partsguru.com – gaggia classic DM1645/002 or 1152/002 Elektrovalve 120V

So, after completely pulling the machine down last night and doing a bit of testing and some internet reading I have a good idea of how they work now, I know how to customise the Over Pressure Valves to produce better shots and I now know which part has failed. All I need to do now is fix/replace the solenoid valve and then I will have two working machines (or I’ll ebay the fixed one to pay for a grinder :)).

The culprit.. C.E.M.E 3-way solenoid valve..

toomuchcoffee.com – gaggia classic OPV issues

coffeesnobs.com.au – gaggia pressure

ruizs.org – gaggia baby pressure adjustment with OPV valve

Grange Controls Ltd. are the sole UK importer for the Italian-made C.E.M.E solenoid valve (5316VN1) I need.

They don’t stock it though. They do stock the coil but not the valve itself. If I can find a multimeter to test the coil then I might buy one from them but they have a minimum order of ?20 (since they usual deal in bulk) + ?2.50 post + VAT.

Now I need a multimeter to be sure it’s the coil and not the valve itself.. In the meantime I’ve bought a Gaggia Classic off ebay and I’m waiting for it to arrive..

Update:

My workmate Chris wanted a multimeter so I walked to Maplins and bought a UNI-T 50II for him and then used it to test the solenoid coil.

It showed the coil has resistance, which, in my limited understanding of basic electronics, means that it’s not completely trashed. This in turn means the problem might be in the 3-way valve itself. So, citric acid bath for it tonight to see if that makes a difference.

The Gaggia store in House of Fraser on Oxford St. don’t answer their phone so I called Gaggia UK’s head office and I’m waiting for a call back from their service department. Kev here suggested they are all on a coffee break 😉

Similar issue with 3-Way Valve reported here…

“If all the vibration from your big fat UKLA pump shakes your machine around enough over the years, the little 14mm nut that holds the coil of your 3-way solenoid to the brass valve body will become loose. If it gets as loose as mine did, it is enough to prevent the 3-way valve from actuating fully. The solenoid just moves ever so slightly on the valve body. This slight movement is enough to screw up your shots.

Pull the reservoir filler funnel off, then take a wrench and lock that thing down and all your “clogged boiler” woes will be gone. No parts to order, no need to take apart your machine.“

3-Way Valve Hows and Whys

How to Backflush