R-Pro › Field cases › Refrigerators & showcases
Drain Trap / Line Freezing — Cold Environment Blockage
Likely causes
Exposed outdoor drain line freezes below 0°C ambient
Check: Refrigeration/freezer systems (cold storage) year-round, AC in winter. Outdoor drain line without insulation freezes within 1–2 hours below 0°C. Same symptoms as clog — indoor leak.
What to do: 1) On freezing event, thaw with hair dryer or warm water (NOT boiling — damages PVC). 2) Wrap entire line with insulation (rubber foam or polyethylene foam). 3) Below -10°C environments require electric tracing cable (heat tracing). 4) Route line indoors or alongside warm-water pipes whenever possible — prevents freezing.
P-trap or low-point line section freezing
Check: P-trap holds water and freezes first when exposed outdoors. Lowest line points also pool water → freeze. Outdoor traps need more than insulation; relocate indoors or use heated enclosure.
What to do: 1) Relocate P-trap indoors (move inside wall). 2) If relocation impossible, add self-regulating heat cable + insulation box at trap. 3) Add auto-drain valve at low points — drains automatically when stopped. 4) For frequently freezing areas, design heated drain system from start.
Freezing event can crack the line or trap — always leak-check after thaw. New installs in freezing regions must be designed with freeze protection from the start; retrofit is expensive and incomplete.
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
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