Beretta Insufficient DHW Temperature / Underheating

Water heater delivers lukewarm water only, not reaching set temperature

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

Partially blocked secondary plate heat exchanger, Incorrect gas rate or low gas pressure, Faulty DHW NTC sensor reading too high, Limescale buildup in DHW circuit

How to Fix / Troubleshooting

Safety: Turn off gas and power before opening the appliance. Hot water circuits can be under pressure and very hot.

  • 1. Check user settings: Confirm the DHW temperature setpoint on the Beretta control panel is high enough (e.g., 50–60°C).
  • 2. Test with single tap: Run one hot tap at moderate flow. If temperature improves at lower flow, the heater may be undersized or restricted by scale.
  • 3. Clean aerators and shower heads: Remove and descale tap aerators and shower heads to ensure proper flow.
  • 4. Descale secondary heat exchanger (technician): A professional can remove the DHW plate heat exchanger and chemically descale it, or flush the DHW circuit with a descaling pump.
  • 5. Gas and sensor checks: Have a technician verify gas pressure and combustion, and test the DHW NTC sensor for correct readings.
Advertisements

Repair Difficulty

Hard 4/5

Required Part

Secondary plate heat exchanger
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements