Vitowell comfort Classic (Slim)

A power trip at home caused by the turning on of the electric water heater is usually related to electrical wiring/ electrical supply problems that fall under these common causes:

• Wrong wiring connection, or worn/damaged cables that has fused or come into contact with each other, leading to a short circuit
• Failure to wire to a dedicated water heater power point/ front flex outlet. A 3-pin socket outlet should not be used because its power rating is insufficient to support water heater.
• Sharing of the power point/socket with other electrical appliance(s) resulting in electrical overload. The power point for water heater should never be shared.
• Faulty heater switch / power point.

Please consult a Licensed Electrician to check and rectify any electrical problem. If the power trip persists even after an electrical inspection, kindly contact Viessmann Service Support to check and service your water heater unit.

There are 2 common reasons why the water from your storage heater is not hot enough:

• Water not fully heated up yet: give some time for the water to be heated up before use.
• Water flow rate at water fixture is too high: hot water stored at the heater is being consumed faster than the rate at which the cold water refilled into the tank can be fully heated up. In such a situation, turn on the water fixture tap partially instead, or install a flow restrictor to reduce the water flow.

Use the light indicators on Viessmann storage water heaters to easily recognise whether the heating process is completed.

Under Singapore regulation SS636:2018, pressure relief valve is necessary to be installed at the cold water inlet of the storage water heater to prevent tank overpressure, leakage, or explosion in worst case. You can find a pressure relief valve included in the accessory pack of every Viessmann storage water heater unit supplied.

Whenever the water pressure at the water heater is too high, the pressure relief valve will release excess pressure through releasing/dripping of water. This releasing/dripping of water will stop when the water pressure is reduced and stabilized.

To check if releasing/dripping of water arise from the normal operation of the pressure relief valve, you can simply turn on water at the shower for 20-30 sec, and observe if the drip at the pressure relief valve stops.

If water dripping occurs permanently, kindly contact Viessmann Service Support to check and rectify on the possible faulty pressure relief valve.

To ensure the best performance from this appliance, it is recommended to replace the magnesium anode, flush out any deposit of salts in the heater tank and descale the heating element once every two years. The maintenance cycle may vary depending on the water quality. It is best to engage a Licensed Plumber or service technician to perform the maintenance operation.