The dip tube routes cold inlet water to tank bottom. Broken = lukewarm water that runs out fast.
Symptoms
- Hot water runs out in 5-10 minutes
- Lukewarm rather than hot
- Sudden onset
- White/cream plastic flakes in faucet aerators
DIY replacement
- Off power/gas
- Close cold supply
- Disconnect cold supply line
- Unscrew cold inlet nipple
- Replace dip tube
- Reinstall with Teflon tape
Cost
- Universal: $5-10
- OEM: $10-20
Bottom line
Cheapest water heater repair.