53
2.
Open drain screw A on the circu-
lation pump. Catch the water in a
suitable container.
Checking and cleaning the burner
Turn off the ON/OFF switch on the con-
trol unit and the power supply.
Close the gas shut-off valve and safe-
guard against reopening.
If required, clean the burner with com-
pressed air or a soapy solution.
Flush with clean water.
Checking the diaphragm expansion vessel and system pres-
sure
Carry out this test on a cold system.
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
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Service