“Regumaq X-25” Troubleshooting
39
138112581-V01.10.2019
9.3
Decalcifi cation of the heat
exchanger
If, during operation, you notice that the potable water is
no longer heated to the required temperature although
the controller does not display a fault and you did not
change the temperature settings, it may be the case
that limescale deposits have formed in the heat ex-
changer.
Due to the high temperatures in fresh water
stations, calcifi cation of the installed heat
exchangers cannot be ruled out in general.
This applies in particular when installing a
circulation pipe.
NOTICE
Risk of environmental pollution
Decalcifi cation chemicals can cause environ-
mental damage if not disposed of properly.
f
Please observe the disposal instructions
provided by the manufacturer of the an-
ti-liming agent.
You can decalcify the heat exchanger once it has been
removed or even while it is installed.
9.3.1
Decalcifi cation of the potable water side
after installation
CAUTION
Risk of scalding due to hot fl uids!
If the station has been in operation, there is a
risk of scalding due to the unintentional dis-
charge of hot water or steam.
f
Allow the system to cool down.
f
Wear safety goggles.
CAUTION
Risk of burns due to hot components!
Any unprotected contact with hot components
may lead to burns.
f
Wear safety gloves.
NOTICE
Risk of damage due to pressure surge!
Sudden fi lling of the station with water may
lead to damage, for instance to the sensors or
sealing points.
f
Always open and close ball valves slowly.
1. Completely disconnect the controller (all poles) from
the power supply.
2. Close the isolating ball valve for potable hot water
(position 7 in Illust. 1 on page 10).
3. Close the isolating ball valve for potable cold water
(position 9 in Illust. 1 on page 10).
4. Close the isolating ball valve for the storage cylinder
circuit return (position 16 in Illust. 1 on page 10).
5. Close the isolating ball valve for the storage cylinder
circuit supply (see position 18 in Illust. 1 on page
10).
6. Unscrew the caps of the fi ll and drain ball valves for
the potable water circuit (positions 4 and 17 in Illust.
1 on page 10).
7. Connect a fl ushing hose to each of the fi ll and drain
ball valves (positions 4 and 17 in Illust. 1 on page
10).
Please observe the fl ow direction of the
anti-liming agent. It must run in the opposite
direction to the intended fl ow of potable water
in the potable water circuit.
Only use anti-liming agents that have been ap-
proved by the DVGW for decalcifi cation of the
heat exchanger, such as those with a citric acid
base. Please observe the DVGW worksheets
W 291 and 319!
8. Open the ball valves slowly (positions 4 and 17 in Il-
lust. 1 on page 10) to initiate the fl ushing process
with the anti-liming agent.
9. End the fl ushing process once the prescribed expo-
sure time has elapsed.
The exposure times are dependent on the
anti-liming agent in use. Anti-liming agents
may need to be heated up. Please observe the
instructions provided by the manufacturer of
the anti-liming agent!
10. Drain the fl uid and the fl ushed limescale from the
fl ushing circuit.
