Vaillant ecoTEC plus 937, Instructions And Maintenance Instructions, Page: 54 / 64

Installation and maintenance instructions ecoTEC plus 0020031552_03 54
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Fig. 9.5 Replacing the primary heat exchanger
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Fig. 9.6 Holder for the primary heat-exchanger
• Pull the plug connection ( 2 ) of the thermal fuse off
the primary heat-exchanger.
• Unscrew the three screws ( 3 ) on the holder of the pri-
mary heat-exchanger.
• Turn the holder to the side around the rivet ( 1 ), pull
the primary heat exchanger downwards to the right
and remove it from the appliance.
• Mount the new primary heat exchanger
• Fit a new burner door seal kit.
• Fit the burner module.
• Continue to replace in the reverse order.
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Note
A new burner door seal kit must be fitted every
time the burner door is removed.
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Caution!
Danger of damage to the primary heat-ex-
changer!
Do not release or tighten the four screws
(Fig. 9.5, Item 4).
Caution!
Insert the „O“-rings for the flow and return
hoses on the primary heat-exchanger using a
suitable lubricant.
Push the flow and return connections up to the
stop in the primary heat-exchanger and make
sure that the seating of the clamps on the flow
and return hoses are correct (see Fig. 9.5).
• Filling and vent the combi boiler as required.
• After completion of the work check the system for gas
leaks and carry out a function test (see Section 7.8).
9.6 Replacing the expansion vessel of the shift
load storage tank
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Fig. 9.7 Replacing the expansion vessel of the shift load stor-
age tank
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Danger!
Before replacing components ensure that the
safety instructions from Section 9.1 are ob-
served.
• Disconnect the appliance from the mains as described
in Section 9.1, and close the gas isolator valve in the
gas supply pipe.
• Close the cold water inlet stop valve.
• Open a hot water tap in order to release the pressure
on the water circuit. Then close the tap again.
9 Replacing components