Replacing The Aqua Sensor; Replacing The Electronics On The Shift Load Storage Tank - Vaillant ecoTEC plus 937 Instructions For Installation And Servicing

9 Replacing components
• Release the spring clamp (5) on the storage tank
charging pump casing (4). Support the storage tank
charging pump with your other hand to prevent it
from falling out of the chassis.
• Pull the storage tank charging pump out of the chassis
downwards.
• Fit the pipe bracket to the new storage tank charging
pump using new gaskets.
• Fit the new storage tank charging pump in reverse
order and use new gaskets.
• Connect the electrical wires of the pump in reverse
sequence. Check for correct routing of the lines.
• Re-fit the discharge pipe (1) and use new gaskets.
• Filling and vent the combi boiler and the shift load
storage tank.
• After completion of the work check the system for gas
leaks and carry out a function test (see Section 7.8).
9.8

Replacing the aqua sensor

1
5
4
3
Fig. 9.9 Replacing the aqua sensor
62
2
Danger!
d
Before replacing components ensure that the
safety instructions from Section 9.1 are
observed.
• Isolate the unit from the mains as described in
Section 9.1.
• Close the gas isolation valve in the gas supply pipe.
• Close the isolation valves in the hot water system and
drain the water out of the combi boiler and the shift
load storage tank.
• Remove the discharge pipe (1) of the heating pressure
relief.
• Separate the electrical wire of the aqua sensor from
the wiring harness by pulling off the plug from the
wiring harness.
• Release the fitting (2) and (3) on the elbows (4)
and (5).
• Turn the Aqua-Sensor slightly to the side and pull the
Aqua-Sensor downwards out of the chassis.
• Remove the pipe elbow from the Aqua-Sensor.
• Fit the pipe elbow onto the new Aqua-Sensor and use
new gaskets.
• Mount the new Aqua-Sensor in reverse order and
replace the seals.
• Connect the line plug of the Aqua-Sensors with the
wiring harness.
• Re-fit the discharge pipe (1) and use new gaskets.
• Filling and vent the combi boiler and the shift load
storage tank.
• After completion of the work check the system for
water leaks and carry out a function test (see
Section 7.8).
9.9 Replacing the electronics on the shift load
storage tank
Fig. 9.10 Replacing electronics
d Danger!
Before replacing components ensure that the
safety instructions from Section 9.1 are
observed.
ecoTEC plus 937 installation and maintenance manual
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