Installation Manual
10 | PSH  Plus  www.stiebel-eltron-usa.com
INSTALLATION  
Maintenance
Fault Cause Remedy
The water does not heat 
up and the ON/OFF indi-
cator does not illuminate. 
The high limit safety 
cut-out has responded 
because the controller is 
faulty.
Remedy the cause of the 
fault. Replace the con-
troller. 
The high limit safety 
cut-out has responded 
because the temperature 
has fallen below 5 °F 
(-15 °C).
Press the reset button 
(see diagram). 
The water does not heat 
up and the ON/OFF indi-
cator illuminates.
The heating element is 
faulty. 
Replace the heating el-
ement. 
The water does not heat 
up sufficiently and the 
ON/OFF indicator illumi-
nates.
The temperature control-
ler is faulty. 
Replace the temperature 
controller. 
The heat-up time is very 
long and the ON/OFF in-
dicator illuminates.
The heating element is 
scaled up. 
Descale the heating el-
ement. 
The T&P relief valve drips 
when heating is switched 
off.
The valve seat is contam-
inated.
Clean the valve seat. 
Water pressure is too 
high.
Install a pressure reduc-
ing valve.
An expansion vessel was 
not installed. 
Install an expansion 
vessel in line with the 
appliance (see plumbing 
schematic).
Reset key, high limit safety cut-out
If the high limit safety cut-out has activated, it should be reset. 
Shut off the circuit breaker connected to the appliance before 
removing the bottom cover and resetting the switch.
15. Maintenance
WARNING Electrocution
Carry out all electrical connection and installation work 
in accordance with relevant regulations.
Before any work on the appliance, disconnect all poles 
of the appliance from the power supply.
If you need to drain the appliance, observe chapter 15.1, “Draining 
the appliance”, pg. 10.
15.1  Draining the appliance
WARNING Burns
Hot water may escape during the draining process.
If is necessary to drain the cylinder for maintenance or to protect 
the whole installation from freezing, proceed as follows:
f Close the shut-off valve in the cold water feed line.
f Open the DHW valves of all draw-off points until the appli-
ance is fully drained.
f Drain any residual water from the T&P relief valve.
15.2  Checking / replacing the sacrificial anode
f Check the sacrificial anode after the first year of use and re-
place if necessary.
f Next, decide the time intervals at which further checks 
should be carried out.
15.3 Descaling
f Remove loose scale deposits from the water heater.
f If necessary, descale the inner cylinder with commercially 
available descaling agents.
f Only descale the flange after disassembly and never treat the 
cylinder surface and sacrificial anode with descaling agents.
15.4 Anti-corrosion protection
Ensure that while carrying out maintenance work the anti-cor-
rosion protection resistor (560 Ω) is not damaged or removed. 
Reinsert the anti-corrosion protection correctly after replacement.
15.5  Replacing the power cable
DANGER Electrocution
The power cable must only be replaced (for example if 
damaged) by a qualified technician.










