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THM0421 026512 Rev. C Apr 13
Thermann Owner’s Manual
250L to 400L Electric Storage Water Heaters
Safety Information
Warning
For safe performance, this water
heater is fitted with:
1. Combination Thermostat and over-
temperature energy cut-out.
2. Combination Pressure &
Temperature Relief Valve.
These devices must not be tampered
with or removed.
The water heater must not be
operated unless each of these devices
is fitted and in working order. Element
covers should be removed only by an
electrician.
The electrical power supply switch
must be turned off and the fuse
removed or the circuit breaker
isolated at the main electrical supply
switchboard before the water heater
electrical cover is removed.
Open the PTR Valve for approximately
10 seconds by lifting the lever on the
valve to ensure water is relieved to
waste through the relief drain pipe.
Lower lever gently and check that it
closes correctly.
The PTR Valve must not be tampered
with or removed. The water heater
must not be operated unless this valve
is fitted and in working order.
The PTR Valve should be checked for
adequate performance or replaced at
intervals not exceeding 5 years, or less
in areas where local regulations apply.
Important
The PTR Valve and its drain outlet
pipe must not be sealed or blocked. It
is normal for the PTR valve to leak a
small amount of water during heating
cycles.
Danger
Failure to operate the relief valve
easing lever at least once every six (6)
months may result in a problem with
the water heater and in some cases
the tank may explode.
