If your Defy fridge is running (you can hear the compressor, and the interior light switches on) but the fridge and freezer are warm, you've likely got a sealed system problem.
Most people call a technician who quotes R2000–R4000 for a gas refill or evaporator replacement. But sometimes, the issue is a small internal leak in an unexpected place – the "hot loop" (Yoder loop) in the freezer section.
Here's how we diagnosed and bypassed it to get cooling back – without replacing the whole fridge.
Symptoms We Saw
- Fridge/freezer at room temperature
- Compressor running continuously
- No hissing or obvious gas leak smell
- Light works, fan runs (in frost-free models)
- Frost on evaporator? No – totally dry
→ That meant the sealed system had lost its refrigerant.
Step 1: Confirming the Leak Location
We pressure-tested the sealed system with nitrogen (R1500 regulator + tank from a local refrigeration supplier).
The leak wasn't on the compressor, filter-drier, or evaporator. Then we checked the condenser loops:
- Side condenser – fine
- Yoder loop (the metal tubing inside the freezer section wall, designed to prevent condensation on the outer cabinet) – bubbles appeared.
On a Defy fridge, the Yoder loop runs just under the freezer inner liner. A tiny pinhole leak there lets refrigerant escape slowly over months.
Step 2: Why Bypassing Works
The Yoder loop is not critical for cooling – it only stops external sweating. In a humid climate like Durban or Cape Town, you might get minor condensation, but the fridge will still cool perfectly without it.
So we decided to remove that loop from the sealed system.
Step 3: Tools & Materials (SA availability)
- R134a refrigerant (available at Mica, Leroy Merlin, or refrigeration shops – about R350–R500)
- Nitrogen for leak checking (rent bottle from Afrox – R800 deposit + gas)
- Cutting tool
- Brazing rod & flux (Mapp gas torch from Builders – R650)
- Bullet piercing valve or Schrader valve
- Vacuum pump (rent from local tool hire – R200/day)
- Copper couplers (R30–R50)
Step 4: Bypass Procedure
- Recover remaining gas (do not vent to atmosphere – illegal in SA).
- Cut the Yoder loop at both ends where it connects to the compressor outlet and before the filter-drier.
- Connect the compressor outlet directly to the filter-drier inlet using a new copper pipe piece.
- Braze all joints – pressure test with nitrogen to R1500 kPa.
- Evacuate system to 500 microns (vacuum pump).
- Charge with R134a – approx 80–120g for a standard Defy 250–300L fridge (weigh it with a kitchen scale).
- Run and monitor – in 2 hours, freezer was at -15°C.
Result
Fridge cooled perfectly. Slight condensation on the outer cabinet near the freezer door – acceptable.
Cost saved:
- New Defy fridge (similar size): R5500–R7000
- Technician repair (replace evaporator): R2800+
- Our DIY bypass: ~R1200 (including gas rental deposit)
Important Warnings
- Refrigerant work is technically illegal without a Gas Cat A or B license in SA.
- If you're not comfortable brazing or handling pressurised gas, hire a fridge tech and tell them: "Bypass the Yoder loop, don't replace the evaporator."
- This fix only works if the leak is truly in the anti-sweat loop – not the evaporator or suction line.
Final Verdict
The Defy fridge's light coming on but no cooling often means a small internal leak in the Yoder loop. Bypassing it is a cheap, permanent fix for an otherwise dead fridge.
We got another 5+ years out of ours – and kept R1500+ in our wallet.
"The light means power, not cooling. Don't throw the fridge away before checking the hidden loops."
Experiencing a similar issue? Contact us for a no-obligation quote. We're here to help.