Maintenance and Repair Guidelines for Water Heater Tanks

Conduct hydraulic strength and tightness tests annually, following the specified pressure guidelines in the operating instructions.
For water heaters with built-in heat exchangers, perform annual descaling to remove scale accumulation in the lower part of the tank. Some designs have a revision flange, while others are equipped with drainage valves for this purpose.
Clean the water heater body with the heat source turned off and the tank emptied, using non-abrasive, non-aggressive, and non-flammable substances.
Check the integrity of the protective magnesium anode annually and replace it if damaged.
Periodically check the operation of the automatic air release valve.
Drain water from the water heater during extended shutdowns.

Fault	Cause	Remedy
Safety valve frequently activates or threaded connections periodically leak	Incorrect setting of the safety valve	Ensure the full opening pressure of the valve is less than the allowable pressure for the tank.
-//-	High water supply pressure	Reduce water supply pressure using a pressure regulator downstream or adjust pump cutoff pressure if supplied from an individual well.
-//-	Missing, incorrectly sized, or improperly adjusted expansion tank	Calculate the volume and pressure setting of the expansion tank using the methodology for calculating expansion tanks, with the heating system referring to the hot water supply system and the temperature graph set to 60 and 59°C.
Water takes a long time to heat to the desired temperature	Heat exchanger surface has become scaled	Clean the heat exchanger to remove scale deposits.
-//-	Low temperature or flow rate of the heating water	Increase the temperature and flow rate of the heating water (in the heat source circuit).
-//-	Insufficient heat exchanger area	Add an external heat exchanger.
Leak in the upper part of the tank	Automatic air vent is not working or missing	Replace the tank.
Technical water from the heating circuit entered the tank, and the pressure in the heating system became equal to the pressure in the water supply system	Leak in the heat exchanger	Disconnect the built-in heat exchanger and add an external circuit with a heat exchanger and circulating pump.