My patients name: Hill glass 4 door reach in icecream case
ailment: aprox. every 6 weeks someone has to deice the fans
1st visit: noticed ice build up is only behind the fan shroud not in the drain or on the evap. my first thought was case is not completly drained when fans come on and water gets pulled back into fans and freezes progressivly building up in layers. i programmed in an exageerated drip time, went from 5min to 15 min.
2nd visit: just a follow up visit to see if ice was back and it was. first off i deiced case by dumping 30 gal trash cans full of water into bottom of case hose wasnt an option. the final pail of water i dumped floor wax in the water first then washed case out with it, thinking perhaps wax would help water bead and flow to drain (act of desperation). i changed a check valve that seemed to be leaking slightly, restarted and checked superheat 30 degrees, hmm uneven frost pattern maybe im onto something. superheat would not dial in for me so i pump it down pull the screen nice n clean so i change orifices in the valve went from a #2 to a #3. visaul inspection of the valve leads me to believe the sys has acid in it (parts have that pretty copper clad look to them)i restart and dial in about a six degree superheat but valve has large swing when it hunts not a good steady reading but case had lots of traffic so im gonna let it balance and recheck.
has anyone out there ran into this or have any thoughts on other things to look at for the source of this?
thanks for your thoughts guys