Two refrigerated cases connected to the same compressor rack do not necessarily need to run at the same temperature. If your system uses evaporator pressure regulators, or EPRs, that difference may be deliberate. The useful question is whether each case is meeting its own documented requirement—not whether both displays match. If product temperatures are outside your establishment's limits, follow its corrective-action plan immediately and request service. Do not wait for a pressure explanation before protecting stock. A warm case alone does not establish low refrigerant, and changing a regulator to match a neighboring case is not a sound diagnosis. Find out which cases are supposed to match Start with case numbers, model labels, and the refrigeration schedule for the store. Ask the service provider to identify which evaporators share the suction group, which have EPRs, and the intended operating condition for each. A floor plan showing adjacent cabinets is not a refrigerant circuit diagram. For example, imagine case A and case B have different documented duties. A service note saying only “B is colder” leaves the main question unanswered. Ask for each case's target, its actual observations, and whether the difference is new. If both cases have the same duty but one recently changed, record that as a fault history rather than assuming the original design was wrong. Keep a short log with the case number, time, displayed reading, product check made under your store procedure, stocking event, and controller message. Photograph the normal operator display. Do not remove panels or attach gauges to collect this information. Why the rack reading cannot describe every evaporator An EPR controls pressure on the evaporator side of the valve. It can keep that evaporator above the lower pressure in the shared suction line. This lets different evaporator groups operate at different temperatures on one suction group. The regulated refrigerant condition is not the same measurement as cabinet air or product temperature. Sporlan's ORIT valves open as inlet pressure rises; the regulated condition is upstream, not simply the reading at the compressor rack. See Sporlan Bulletin 90-20, pages 3–5 . The practical consequence is a better service question: “Which measurement describes this case, and where was it taken?” Request labeled evaporator-side and common-suction findings, the operating mode, and the technician's interpretation against the equipment design. Leave the measurements and adjustments to qualified service personnel. A report that lists one pressure without a location is incomplete for this decision. Ask for the missing context before accepting a conclusion about the whole lineup. Likewise, keep measured product, air, and refrigerant conditions separately labeled; they answer different questions. Match the temperature change to what was happening After a display change: photograph the loading arrangement and any signs near the air path. Hussmann's manual for its medium-temperature bulk-produce and bakery merchandisers requires clear discharge and return openings and observance of the marked load limits. It also directs users to the case data sheets for operating temperatures and defrost requirements. These instructions illustrate why the actual cabinet documentation matters; they are not specifications for every case. See the Hussmann manual, section 4-1 . Restore only the owner-accessible loading arrangement specified for your model, and document whether the problem persists. Around defrost: record the controller state and the time the case returns to its normal operating display. The SORIT and SORIT-PI arrangements described in Bulletin 90-20 combine pressure regulation with a suction-stop function used during defrost; the exact valve and control arrangement matter. Ask the technician to compare the observed sequence with that arrangement. An isolated reading during a mode change is not enough to condemn the regulator. At otherwise comparable times: send the service provider the repeated pattern, including whether one case or several are affected. Request an investigation that accounts for loading, control state, and the affected branch. This is a way to organize the visit, not a test that identifies a failed component. What a regulator-replacement proposal should explain A replacement proposal should identify the installed valve and why it cannot meet the required duty. Connection size alone does not establish the right selection. As a separate manufacturer example, Danfoss's KVP data sheet, pages 5–7 , bases selection on refrigerant, evaporator duty, operating temperatures, and available pressure drop. Its opening setting and full-flow condition are also different concepts. These are reasons to request a documented selection, not permission to substitute a KVP for a Sporlan valve. Ask the quotation to separate the diagnosis, proposed part or adjustment, and acceptance check. A useful request is: “Please identify the affected branch, explain the evidence for this repair, and state how you will verify that both cases meet their individual requirements afterward.” That makes the expected result reviewable without asking the operator to calculate valve settings. If the quotation includes refrigerant work, collect the current system identification and service history using our equipment and refrigerant identification guide . If an identified R404A installation is being considered for a refrigerant change, the separate R404A replacement decision guide explains the questions to take into that discussion. Neither a valve name nor a case-temperature difference identifies the installed refrigerant or proves that a change is needed. A decision path for the service call What you know Next action Evidence to request The cases differ, but their intended duties are unknown Get the case schedule before requesting matching settings. Case IDs, circuit mapping, and individual requirements. The change followed stocking or a controller mode change Record that event and follow the applicable operator instructions. Layout photos and a timestamped operating history. The service report gives only rack suction pressure Ask how the affected evaporator was assessed. Labeled measurement locations and operating state. A valve replacement or adjustment is proposed Request a diagnosis and a defined completion check. Installed model, selection basis, and results for each affected case. Product is outside the store's limits Apply the store's corrective-action plan and arrange service promptly. Temperature history, affected stock, and actions taken.