How to Troubleshoot Common PEX Pipe Problems
PEX (cross-linked polyethylene) piping is durable, but issues can arise due to installation errors, environmental factors, or material defects. Below are common PEX problems and how to fix them.
1. Leaking PEX Connections
Causes:
Improper crimping or expansion of fittings
O-ring failure in push-to-connect fittings
Over-tightening or under-tightening clamps
Solutions:
✔ Check crimp rings – Use a go/no-go gauge to verify proper compression.
✔ Inspect O-rings – Replace if cracked or worn (common in SharkBite fittings).
✔ Re-press or re-crimp – If leaks persist, replace the fitting.
2. Reduced Water Pressure
Causes:
Kinks or sharp bends in the tubing
Clogged pipes (mineral buildup or debris)
Undersized PEX tubing for the flow rate
Solutions:
✔ Straighten kinks – Use a heat gun (low setting) to reshape the pipe.
✔ Flush the system – Remove debris by opening multiple faucets.
✔ Upgrade pipe size – Use ¾-inch PEX for main lines instead of ½-inch.
3. Discolored or Smelly Water
Causes:
Bacterial growth (biofilm) inside pipes
Chemical leaching from low-quality PEX
Hot water degradation (if PEX-B is used above 180°F)
Solutions:
✔ Flush pipes with chlorine (1 tsp bleach per gallon, rinse thoroughly).
✔ Use PEX-A or PEX-AL-PEX (better for hot water).
✔ Install a water filter if odor persists.
4. Frozen & Burst PEX Pipes
Causes:
Poor insulation in cold climates
Sudden temperature drops
Solutions:
✔ Thaw carefully – Use a hair dryer (never an open flame).
✔ Insulate pipes – Use foam sleeves in unheated areas.
✔ Replace burst sections – Cut out damaged PEX and install a sharkbite coupling.
5. Fitting Failures (Cracks or Leaks)
Causes:
Cheap brass fittings corroding
Excessive stress on connections
Improper expansion technique
Solutions:
✔ Use corrosion-resistant fittings (DZR brass or polymer).
✔ Support pipes properly – Avoid strain on joints.
✔ Follow manufacturer's expansion tool instructions.
6. UV Damage (Brittle or Cracked PEX)
Causes:
Sunlight exposure degrades PEX over time
Solutions:
✔ Replace exposed PEX with UV-resistant tubing or cover with insulation.
✔ Paint PEX with latex paint for temporary UV protection.
Preventive Tips
✅ Pressure test new installations (1.5x working pressure).
✅ Use PEX-AL-PEX for oxygen-sensitive systems (e.g., radiant heating).
✅ Avoid direct sunlight and extreme heat near PEX.
When to Call a Professional
Major leaks behind walls
Persistent water quality issues
Complex rerouting needed
