Replacing The Storage Tank Pump Of The Shift Load Storage Tank; Replacing The Aqua Sensor - Vaillant ecoTEC plus 937 Instructions And Maintenance Instructions

• Remove the screw on the cover of the shift load stor-
age tank.
• Remove the cover.
• The expansion vessel (1) is freely accessible
• Release the nuts (2) on the expansion tank.
• Pull the expansion tank (1) off the pipe fitting and re-
move it from the EPS trough.
• Insert the new expansion tank in the EPS trough.
• Re-connect the new expansion tank. Use a new gasket:
• Check the pressure of the expansion tank (minimum
pressure 4 bar).
• 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).
9.7 Replacing the storage tank pump of the shift
load storage tank
1
6
5
4
Fig. 9.8 Replacing storage tank pump
Danger!
d
Before replacing components ensure that the
safety instructions from Section 9.1 are ob-
served.
• Isolate the unit from the mains as described in Sec-
tion 9.1.
• Close the gas isolator valve in the gas supply pipe.
• Close the stop valves in the hot water system and
drain the water out of the combi boiler and the shift
load storage tank.
Installation and maintenance instructions ecoTEC plus 0020031552_03
• Remove the discharge pipe (1) of the heating pressure
relief.
• Lower the electronics box as described in Sec-
tion 4.19.2.
• Unclip the back cover of the electronics box and swing
the cover upwards to reveal the connections.
• Pull the plug X12 off the electronic printed circuit
board.
• Pull the free end of the line carefully through the
entry grommets on the combi boiler and on the shift
load storage tank.
• Release the sensor wire of the pump from the wiring
harness by pulling the plug off the wiring harness.
• Unscrew the sheet metal bracket (6) from the chassis.
• Release the fitting (2) on the connector pipe (3).
• 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 chas-
sis 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
1
2
3
5
4
3
Fig. 9.9 Replacing the aqua sensor
Replacing components 9

Replacing the aqua sensor

2
55