Mini won't pump

Did your new Mini work fine initially but have an in warranty (year one) problem later. Post here for advice. Later report on your fix. Posted photos documenting repairs are encouraged.
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MassJava

Mini won't pump

Post by MassJava »

Buyer's Remorse Mini II bought from Chris Coffee about one year ago. Until recently it has been working well. About 2 weeks ago it started to leak small amounts (5 - 10 cc's per day?) from the back.
2 days ago it stopped pumping. At first it would pump but not finish a shot. Looking at the dispersion screen during a shot I could see many small bubbles and it would sputter some water. Last night I tried to refill the boilers -thinking there was air in the system- it stopped pumping water. Only air with a very small amount of water. Now on power up only the boiler and 92 lights come on - blinking. No standby light. Pump seems to be running just not pumping water.

Can you please help.
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chas
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Re: Mini won't pump

Post by chas »

It sounds to me like you possibly have a loose or cracked tube / pipe on the inlet side of the pump that leaks water when the pump is off and sucks in air when the pump runs.
Chas
LM GS/3 & LaSpaziale Dream v 1.25 (US 120V)
Mazzer Kony E, Customized Rocky
Hottop P/B
MassJava

Re: Mini won't pump

Post by MassJava »

mini1.JPG
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Removed left side and back panels. I cannot see any sign of leaking, cracked or damaged tubing. Rinsed the tank valve and verified that it functions.
Still will not pump. Makes a rhythmic whooshing sound. Is there any way to reset the blocking alarm (Blinking boiler light). I have tried simply unplugging.
Pictures of tubing connections on intake side of the pump.
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chas
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Re: Mini won't pump

Post by chas »

The blinking 92 light is normal. It just means that the group boiler is heating up. The blinking steam boiler light and subsequent blocking alarm happens when the boiler doesn't fill up within one minute. Unplugging and plugging back in will clear the alarm, but if the problem causing it is still there, it's just going to happen again. At this point it sounds like the pump is full of air and needs to be primed. Have you tried using the procedure in section 4.3 on page 5 of the User's Manual?

You probably have to get the pump primed in order to get water back into the system first so that you can determine where the leak is, then fix the leak.
Chas
LM GS/3 & LaSpaziale Dream v 1.25 (US 120V)
Mazzer Kony E, Customized Rocky
Hottop P/B
MassJava

Re: Mini won't pump

Post by MassJava »

Hi Chas

I reprimed the pump. (Not patient enough on first attempt). After pumping over a liter of water through the group head almost all the air is now out. It still sputters occasionally . When I pull a blank shot there is a small leak at the tank outlet valve (maybe needs new o-rings). There are still some bubbles in the plastic tubing connecting the group boiler OPV with the inlet side of the pump. Also 15 minutes after pulling a blank shot the group pressure gauge reads 5 bar. It returns to baseline very slowly.
Endo

Re: Mini won't pump

Post by Endo »

This sounds like a classic case of air getting sucked into the system.

You've already figured out how to bleed the system, the next step is to find the source of the air leak.

I've only heard of it happening at the reservoir (never near the pump), and it usually occurs in 1 of 2 ways:

1 - By far the most common is the filter reservoir filter of lines. Often the filter or the inlet line is simply floating near the top (or it's too high so that it sucks air before float sensor indicates you're low on water). Simply lower it or remove the filter.

...but if you also have a water leak then:

2 - Second most common is a seal leak at the inlet (usually cause by the female potion of the reservoir inlet not fully engaging). This is fixed by either pushing in the front cover (which stops the reservoir from pushing all the way in), or bending the frame tab where the male inlet mounts. As you say, could also be the o-ring (possibly cracked or needing lube), though I've yet to hear of this occuring.
MassJava

Re: Mini won't pump

Post by MassJava »

I am making espresso again. Replaced the old fitting (male) connecting the pump inlet tubing to the tank with a new one sent by Jason from Chris Coffee. The new fitting is slightly longer (1 - 2 mm) and seats more firmly in the tank receptacle. The old fitting had no teflon tape, only a broken black plastic gasket. There was no o-ring in the female (tank) fitting. All back together again last night. A bit of a struggle with the side panels, but now all is well. Thanks for the help. Happy Holidays.
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chas
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Re: Mini won't pump

Post by chas »

Glad to hear that you are back in bidness. From all the posts on this forum about this and similar issues, that area of the Mini design seems to be the weak spot.
Chas
LM GS/3 & LaSpaziale Dream v 1.25 (US 120V)
Mazzer Kony E, Customized Rocky
Hottop P/B
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