Saunier Duval Thema CONDENS F 18 E SB Instructions For Use Installation And Servicing page 42

14.5.1 Dismantling the burner unit
• Remove the silencer (see chapter on
"Maintenance").
• Disconnect the ignition and control
electrode connector (7) from the ignition
module.
• Remove the gas pipe (10).
• Remove the connectors from the gas
valve (9) and the fan.
• Loosen the 4 nuts (5).
• Remove the burner unit (4) from the
heat exchanger (13).
The screws (1) welded to the heat
exchanger must not be damaged.
Otherwise, replace the heat exchanger.
The sealing on the burner door on the
burner unit must not be damaged. If it is,
replace it.
14.5.2 Cleaning the heat exchanger
• Clean the resistance (14) in the heat
exchanger (13) using ordinary vinegar.
• Rinse with a high-powered jet of water.
14.5.3 Burner verification
The burner (3) needs no maintenance or
cleaning.
• Check that its surface is not damaged.
If necessary, replace the burner.
• After checking or replacing the burner,
assemble the burner unit (4) as
described in the following chapter.
14.5.4 Assembling the burner unit
• Replace the gasket (2).
• Place the burner unit (4) on the heat
exchanger (13).
• Progressively tighten the 4 nuts (5)
diagonally.
• Replace the silencer.
• Connect the gas pipe (10) with a new
gasket to the burner unit (4).
• Connect the ignition and control
electrode connector (7) to the ignition
module.
• Connect the gas valve (9) and the fan
(11) connectors.
• Open the appliance's gas inlet.
• Check for gas soundness.