Descale an electric water heater.
Before any intervention, do not forget to cut off your arrival of water and electricity.
Step 1: Prepare the workspace.
With a multimeter, check that there is no power at the water heater terminals.
Disconnect the power and ground wires.
Remove the back cover of the water heater by unscrewing its fasteners.
Step 2: emptying the tank by the safety group.
To recover the scale, it is necessary to start by removing the water which is in the tank by draining it.
Provide a bucket to collect water from the tank and a mop for overflows.
Open the boiler purge valve at the safety group (the mechanism that receives the cold water supply, usually located on the side of the water heater).
Make a draft by opening a hot water faucet to speed up the drain.
Wait until there is more water flowing (depending on the size of your tank the emptying will be more or less long).
Step 3: Remove the resistors.
To access the heart of the water heater, where the tartar is located, you must remove the resistors. It is advisable to wear gloves during this stage because the water that remains at the bottom of the tank is very hot.
Remove the six attachment nuts from the resistance holder with a pair of pliers.
Then gently remove the support on which the resistances are attached to open the tank, while carefully preserving the neoprene seal that you will reuse when reassembling the group.
Step 4: empty the tank.
If your water heater is vertical, the limestone will fall by itself.
If your water heater is horizontal, it will remove the limestone using a vacuum cleaner water and dust.
Rub the sides of the tub with a cloth.
Check the condition of magnesium electrodes that are usually screwed or clipped inside the tank. If they seem damaged, do not hesitate to change them.
Rub the resistors with a wire brush and the anode (an electrode next to the resistors).
Step 5: Reassemble the water heater.
Replace the neoprene gasket.
Install the bracket and resistors over the gasket and then reattach them by tightening the nuts on the support plate (the nuts should be tightened diagonally, in stages, and moderately so as not to damage the gasket).
Reconnect all electrical connections.
Close the drain cock that you opened for draining.
Reactivate the water circuit to check for leaks.
Close the back cover of your water heater by screwing its fasteners back on and turn on the power.