Lack of ice

[suva134a]

Troubleshooting a Manitowoc QY1304A, complaint of not making enough ice. Havests ice once every 15 minutes but only drops about 75% of the ice off the evaporator. The upper left quadrant doesn't get cold enough to freeze the water and has missing cubes. Is this a pressure issue? Another guy looked at it and said, "your evaporator is going bad and needs replaced".

[Yuri B.]

The condenser is clean, if cooled by air ? If by water, flow is good and filter is clean?

[suva134a]

It's air cooled with a filter over the coil, and I just changed the filter to see if that changes anything. The filter was a little dirty, but there should have been plenty of air flow. I ran it without the filter and still noticed 25% of the evaporator without ice. I'm headed back to look at it again.

[Magoo]

Short of gas, what are the suction and discharge pressures. If coil / HX is not flooded low ice volume. Some had those dodgy discharge by-pass valves to maintain liquid supply pressure from discharge to condenser outlet, if they go wild they can really screw things up. Check with a thermometer. If in doubt pinch it off with a pinch off tool and watch changes with pressures and coil flooding.
Just a thought.
Magoo

[FEISTY]

Look at top left corner of evaporator and see if any plastic is cracked. Next check for contact of evap coil pass to grid. Evaporator may have run with extra thick ice and expansion separated grid from coil. The evaporator can be replaced but check date of purchase both for warranty coverage and for age of unit. The repair often ends up no where near a factory job. Also be careful hooking up manifold with long hoses to system. ***** charge on an ice machine is critical for operation. I use a set of gauges connected to a short quick coupler to minimize ***** loss. Good luck. Call Manitowoc tech support. They are usually very helpful. Just have specs and temps on hand as listed in the pocket manuals. They will be asked for.