Junkers Internal Water Leak

Water heater leaks water from the bottom of the casing.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Corroded primary heat exchanger, Leaking DHW heat exchanger (on combi units), Loose union or gasket on water connections, Faulty safety valve or drain plug

How to Fix / Troubleshooting

Safety: Turn off power and close the cold water inlet. If leak is severe, also close gas and isolate the appliance.

  • Identify source: Remove the front cover and use a flashlight to locate the highest visible wet point. Do not touch hot surfaces.
  • Tighten unions: Carefully tighten accessible compression nuts or union connections slightly; do not overtighten.
  • Check safety valve: If water is dripping from a discharge pipe, the safety valve may be opening due to overpressure or failure.
  • Corrosion: If the heat exchanger body is corroded and leaking, it must be replaced by a professional; do not attempt to weld or seal it.
Advertisements

Repair Difficulty

Professional Required 5/5

Required Part

Primary Heat Exchanger / Safety Valve
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements