Marco JET 6, Service Manual

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JET6 ServiceManual.docx 29/09/2015 Revision 2 Page 16 of 34
9. TROUBLESHOOTING:
TROUBLESHOOTING
–GENERAL DIAGNOSTIC GUIDE:
The Jet 6 may have problems which the electronics are unable to detect.
LOW WATER OUTPUT
The brew water should exit the sprayhead at approximately 2.1L/minute. During water calibration it
should discharge 1000-1200g of hot water (960-1150ml).
Probable causes:
1. The hose exiting the pump is kinked which restricts flow.
2. Other hoses exiting the upper circulation chamber are kinked which can effect flow.
3. The pump is faulty or is clogged/jammed.
4. Incorrectly calibrated.
Action required:
1. Check for kinks in all hoses.
2. Check pump operation. Although the pump may function it may not be outputting an
adequate supply. During calibration it should output 1000-1200g of water, or if dispensing
using the hot water dispense outlet it should be approximately 2L per minute. The tube
coming from the pump may be temporarily removed from the metal Y piece and fed directly
into the basket, this can rule out any plumbing issues, a higher flow rate of 4-6L/min will be
expected from the pump when operated in this way.
3. Recalibrate the water dispense. If a faulty scales is used the volume will be incorrect.
HIGH WATER OUTPUT
The brew water should exit the sprayhead at approximately 2.1L/minute. During most brew cycles
the solenoid valve feeding the sprayhead should close at which time no water should exit the
sprayhead after a draining time of approx. 10 seconds after the solenoid closes.
Probable causes:
1. The valve feeding the sprayhead is faulty. The valve mounts onto a metal tube with some
silicone tube. If too much tube is used it can rise up over the top of the metal mounting tube
and cause the valve’s plunger to be forced into an open position. As both the valve and
silicone tube are transparent it may be possible to see if the silicone tube is past the top of
the metal tube.