# Problem with Gaggia Classic: flow stops when heats up



## ECA (Sep 14, 2012)

Hope someone can help me with this.

My Gaggia Classic has developed an odd fault where the flow stops a few minutes after being turned on. I think it may be heat related as it then wont work again until after the machine has cooled down. It will work fine for maybe 5 minutes but then nothing. I did manage to catch it stopping mid-espresso yesterday. The water was coming through the brew head as normal, then there was a slight click, a flow of water through the overflow pipe and nothing more from the brew head.

Any ideas?


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## MartinB (May 8, 2011)

The click sounds like the issue may be with your 3 way valve/solenoid.


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## MelonCoffee (Jun 21, 2012)

From the symptoms described the click (most likely) is coming from the 3 way solenoid valve. (as Martin suggests) This, however, is unlikely to be the 'problem'. Solenoids (with the exception of leaks) either work or not, rarely do they sometimes work. The problem is more likely to be a loss of power to the valve coil. Some technical expertise and a multi-meter is probably the next step.

Good luck.


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## ZioBuck (Sep 21, 2012)

ECA said:


> Hope someone can help me with this.
> 
> My Gaggia Classic has developed an odd fault where the flow stops a few minutes after being turned on. I think it may be heat related as it then wont work again until after the machine has cooled down. It will work fine for maybe 5 minutes but then nothing. I did manage to catch it stopping mid-espresso yesterday. The water was coming through the brew head as normal, then there was a slight click, a flow of water through the overflow pipe and nothing more from the brew head.
> 
> Any ideas?


Hi

It sounds possibly that the vibration pump , if the coil is warmer than normal ? The pump is getting old and loosing performance when machine is warm and pressurized.


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## ECA (Sep 14, 2012)

Thanks everyone. So basically, it doesnt sound like an easy fix. If you're right Ziobuck, does that mean the pump may need to be replaced?

Im just wondering if its worth getting it serviced or should I keep an eye out for another one.


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## peteb (Oct 17, 2012)

if it is the 3 way solonoid valve it is a relatively easy repair. the actual coils can break down over time or if kept energised for a long period.

they are normally held onto the machine by 2 allen head bolts.

not that difficult to remove and replace so long as you take your time and remember where bits go. digital cameras are a good idea when you take things apart if your unsure.

outside link to a manual might be the right one .. http://www.partsguru.com/user/Parts%20dagram%20ER0182_Rev01.pdf


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## RodMB (Jan 17, 2014)

I have exactly the same problem as described that has developed with an old Rancilio Nancy. I get 2 to 3 shots from grouphead from when the machine is cold, then water seems to be diverted back to tank via 3-way valve with no water to grouphead, (even with no portafilter attached). Allowing machine to cool allows water back to grouphead for a short period of time.

I had thought the problem was a sticky overpressure valve, but now I'm thinking it may be the solonoid that needs replaced. As original poster describes I have heard an audible 'click / clunk' when the water pressure to grouphead stops, if the pump is running at the time.

I'd be interested to know how the OP got on / any others thoughts on the problem.

RodMB


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## El carajillo (Mar 16, 2013)

There is a problem that can occur with older vibe pumps that causes them not to supply full pressure. It can be caused by having the M/ch on for long periods (pump getting hot) also from water in tank getting too warm for the pump. There is a small plastic bead in the pump which acts as a one way valve, through age and heat this bead can become deformed and does not fully seal the valve and allows the water to flow backwards and does not create/ achieve full /normal pressure. Allowing the M/ch to cool achieves a temporary recovery. The bead is not a replaceable part, the only option is to replace the pump "IF IT IS THIS"

Solenoids tend to work or not work, other than particles of scale blocking the tiny ports they are reliable.


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## RodMB (Jan 17, 2014)

Thanks for reply El carjilio. I note your proviso, (re - "if this is it") and I actually replaced the pump recently as I thought it was failing. I note your comments regarding the reliability of solenoids although the machine is now pushing 30 year old so I'm not ruling anything out!

My initial thoughts had been the OPV was sticking, (perhaps due to increased pressure from the new pump cause the spring to move into an area of the piston that it didn't usually travel previously), but the identical description of the problem on this thread made me wonder about the solenoid.

I'm not actually 100% clear what the function of the solenoid is - my understanding is the OPV is mechanical in nature, releasing excess pressure into the overflow return to the tank. There is definitely water flowing through this pipe at all times when the pump runs, but increased when the water 'fails' to come through the group head when the machine is hot.

Grateful for any thoughts on problem from anyone.

(For info I live in Highland Scotland, so soft water although given machine ages might be scaling I suppose.)


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## El carajillo (Mar 16, 2013)

Sounds like partial blockage in the solenoid valve,the ports in the valve are very tiny therefore a minute particle will slow/stop the flow.There are two parts to the assembly, the valve and the solenoid .You will need to remove the complete assembly, pull of wires and note positions.Use a 4 mm allen key to release the complete assembly from the M/ch.

Undo the nut on top of black box (solenoid and lift off). Carefully hold the valve body in a vice OR screw it to a piece of wood and undo the large nut, it is fairly tight.

Separate the components and pay attention to how they fit!!, best done on a table to not lose drop any bits.Examine the seals an metal seats and blow through to remove any potential particles /debris. Reassemble and refit. NB Take care not to lose or displace the small "O" rings where the S/valve fits to boiler/M/ch

OPV's are fairly reliable, just check for any git in seat /or damage to seat.


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## RodMB (Jan 17, 2014)

Thanks again for reply - I've little to lose by trying this, as I'm kinda resigned to buying an new machine. Bit sad as a lot of sentimental attachment but who knows - maybe coffee will taste better! I'll post with update when I get a chance to disassemble at weekend.


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