Replacing The Primary Heat Exchanger - Vaillant ecoTEC plus 937 Instructions For Installation And Servicing

9 Replacing components
9.5

Replacing the primary heat exchanger

d Danger!
Before replacing components ensure that the
safety instructions from Section 9.1 are
observed.
• Disconnect the appliance from the mains as described
in Chapter 9.1, and close the gas isolation valve in the
gas supply pipe.
• Close the isolation valves in the flow and return pipes
and drain the water out of the combi boiler.
• Remove the compact thermo module as described
under 7.2.1.
• Remove the expansion tank as described under 9.4.
• Pull off the condensate pipe which runs from the
primary heat-exchanger to the siphon.
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Fig. 9.5 Replacing the primary heat exchanger
• Remove the clamps (1) and (2) and pull off the flow
and return hoses from the primary heat-exchanger.
• Unscrew the four screws (3) on the holder of 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
• Unscrew the three screws (3) on the holder of the
• Turn the holder to the side around the rivet (1), pull
• Mount the new primary heat exchanger
• Fit a new burner door seal kit.
• Fit the burner module.
• Continue to replace in the reverse order.
h
a
• Filling and vent the combi boiler as required.
• After completion of the work check the system for gas
the primary heat-exchanger.
primary heat-exchanger.
the primary heat exchanger downwards to the right
and remove it from the appliance.
Note
A new burner door seal kit must be fitted every
time the burner door is removed.
Caution!
Danger of damage to the primary heat-
exchanger!
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).
leaks and carry out a function test (see Section 7.8).
ecoTEC plus 937 installation and maintenance manual
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