Troubleshooting a Frosting Display Case Evaporator and Logging the Fix for the Next Visit
A multideck display case packing ice across the back of the coil is rarely "just add gas" — it's almost always airflow, defrost, or a door/gasket issue starving the evaporator. R-Pro's field app walks you from the iced-up symptom to the real cause and repair steps on-site (fully offline), and the office ERP turns that same visit into a quote, a tax invoice, and a parts deduction without you re-typing a thing.
On-Site: Reading a Frosting Display Case Evaporator Correctly
- Look at WHERE the frost is: even frost across the whole coil points to a defrost failure (stuck heater, failed termination/defrost sensor, or a timer/EMS schedule that never fires), while heavy frost on the inlet side only points to low charge or a starving TXV.
- Check airflow before touching refrigerant — a single seized or LED-fan-board evaporator fan, a clogged coil, a bag of product blocking return air, or iced-over fan blades will frost a coil that has a perfectly normal charge.
- Confirm the defrost cycle actually completes: force a manual defrost, watch the heater amp draw, and verify the case clears down to bare fin and the drain isn't frozen and backing water onto the coil.
- Pull suction pressure/temperature and superheat so you can tell a real undercharge from an airflow problem — frost plus normal-to-high superheat usually means airflow or defrost, not gas.
- Scan the case's nameplate with the field app so the model, refrigerant (R-448A/R-449A/R-290, etc.), and defrost type are captured to that exact unit instead of scribbled on a work order you'll lose.
Back at the Office: Quoting, Invoicing, and Parts for the Repair
- Build the quote in the ERP from the actual fix — evaporator fan motor or LED fan board, defrost heater, defrost termination sensor, EMS schedule reprogramming, or labor for a full strip-and-clean of the coil.
- Set your own country's tax on the invoice — VAT, GST, or sales tax with your name and rate — and issue a proper tax invoice the store's accounts team will accept without a phone call.
- Pull the fan motor or heater out of inventory on the job so stock counts down automatically, and fire a purchase order to your supplier when you drop below your reorder point.
- Post the visit to accounting in one shot: the sale, the cost of the part (purchase), and any expense flow into sales, purchases, and net profit so month-end isn't a guessing game.
- Keep the store on a customer ledger so recurring display-case calls, balances, and paid/unpaid status are all in one place per account.
The Connection: Why This Coil Frosts Again Next Quarter
- Frosting display cases are repeat offenders — the fix today (cleaned coil, new fan) doesn't matter if the next tech doesn't know the EMS defrost schedule was wrong or the drain line was marginal.
- Log the root cause, parts used, and superheat readings to that unit's service history so the next visit opens with the full story instead of starting the diagnosis from zero.
- Add a voice memo on-site ("swapped LED fan board #2, defrost term sensor reads open below 18°F, recommend new drain heater next PM") so the detail survives even when your hands are full and cold.
- Because the field visit and the office books are one system, the invoiced repair and the logged cause live on the same customer record — no double entry, no lost paper, no surprise when the case ices up again before summer.
Diagnose it in the case, bill it from the office — one system
R-Pro gives you two strong tools working together: a field app that diagnoses frosting evaporators, airflow, and defrost faults from 600+ real refrigeration cases, scans nameplates, takes voice memos, and logs the fix per unit fully offline — and an office ERP that turns that visit into quotes, tax invoices in your own country's tax, inventory, supplier orders, and accounting. One subscription, 10 languages, field work flowing straight into the books.
Get R-Pro →FAQ
My display case coil is frosting but the charge looks fine — what should I check first?
Airflow and defrost, in that order. Verify every evaporator fan is spinning (a failed LED fan board or seized motor is common), check that the coil and return-air path aren't blocked, then force a defrost and confirm the heater clears the case down to bare fin and the drain isn't frozen. Even frost across the whole coil is a defrost problem; inlet-side frost with high superheat is more often airflow than gas.
How do I tell a low charge from an airflow problem on a frosting evaporator?
Read superheat. A genuine undercharge usually shows high superheat with low suction and a coil that's only partly cold or frosting at the inlet. An airflow or defrost issue typically shows the whole coil iced over with normal-to-high superheat and a fan that isn't moving air. R-Pro's field app maps these symptom patterns to causes and repair steps from real cases so you confirm before you connect gauges to gas.
Can I record the fix per individual display case, not just per store?
Yes. Scan the case nameplate and the field app ties the model, refrigerant, defrost type, parts used, and your voice memo to that specific unit's service history — so the next visit to that case opens with the full diagnosis already on screen.
Does the on-site repair flow into my quote and invoice automatically?
It does. The parts and labor you log become the quote and the tax invoice in the office ERP, inventory counts down, and the sale, purchase, and net profit post to accounting — one entry on-site, no re-typing back at the desk.