Brand: AEG
Category: Heating
Document Type: Manual
Language: EN
Manual for MTH 350
Uploaded: April 20, 2026, 7:48 p.m.
Warranty Information
The warranty period is 24 months for private household use and 12 months for commercial use.
This manual provides instructions for the AEG MTH 350, MTH 440, and MTH 570 instantaneous water heaters. It covers operation, installation, safety, and maintenance.
Operation: Open the tap to activate the heating system. Adjust water temperature by controlling the tap flow rate or mixing cold water. Ensure the water supply is uninterrupted to prevent damage to the heating system.
Installation: Must be performed by a qualified contractor. Follow all safety regulations and ensure proper connections. Special attention is required for electrical connections and earthing.
Safety: Be aware of scalding risks due to hot water. Children should not operate or play with the device. Ensure electrical safety through proper installation and maintenance.
Maintenance: Regular cleaning of the aerator and sieve is recommended. Descaling may be necessary. Electrical safety checks should be performed by a professional.
Troubleshooting and error codes
| Problem | Cause | Remedy |
|---|---|---|
| The appliance will not start despite the DHW valve being fully open. | The aerator in the tap is scaled up or dirty. | Clean and/or descale the aerator or replace the special aerator. |
| The sieve in the cold water line is blocked. | Clean the sieve after shutting off the cold water inlet line. | |
| The heater is faulty. | Check the resistance of the heating system and replace the appliance if required. |