MDC XT12HR 2021 - Plumbing; Water Heater Trouble Shooting; Gas Operation; Water Supply

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Plumbing
Water Heater Trouble Shoong
Gas Operaon
Symptom
Cause
Remedy
When switching on, the heater does not
operate.
No 12 V DC supply voltage.
Check the power supply (operaon
voltage min. 10.5 V). Check the
Truma UltraRapid fuse (refer to
maintenance “Fuses”).
When switching on, the heater does not
operate, and the red lamp lights up aer
approx. 30 secs.
– Cowl cover fied.
– Air in the gas supply.
– No gas supply.
– Incorrect gas pressure.
Remove cowl cover and / or clear
any obstrucon.
Check gas valves and gas cylinder.
To unlock (and purge air), switch off
the appliance, wait 5 minutes, and
switch on again.
Heater operates for a prolonged
me and then the red lamp lights up.
Excess temperature
thermostat has responded.
Check water level, refill if required
(close drain valve).
To unlock, switch off the appliance,
wait 5 minutes, and switch on again.
Water Supply
Symptom
Cause
Remedy
Water drips from the P&T safety
valve.
– Water pressure to high.
– Lime or dirt under the P&T safety
valve seat.
Check water pressure (max. 400 kPa),
use a pressure reducer
when connected to central water
supply.
Allow the appliance to cool and then
slowly raise the test lever (Fig. 2a –
4a) to flush the water system and
aempt to force dirt or foreign
maer out of the P&T safety valve
seat.
Replace P&T safety valve. This must
be performed only by a cerfied
service technician.
When opening the cold water tap,
hot water comes out.
– Hot water flows back through the
cold water supply.
-Fit a non-return valve in the cold
water supply (refer to installaon
instrucons “Water connecon”).
-Non return valve faulty