E93.1001EN.C Manual CD
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Gas/air ratio
With every service check and/or maintenance of the water heater always check the gas/air ratio by measuring the
CO
2
percentage (flue gas) at the maximum and minimum load of the water heater. If necessary adjust these
values, see for information chapter 14 “Adjusting and setting the burner”.
Pump
Check the electrical parts and the motor of the pump for a correct functioning. The pump must generate a sufficient
water flow over the (heat exchanger of the) water heater. When the pump produces noise, is operational for more
than five years or has signs of water leakage it is recommended to replace the pump as a precaution.
When defects and abnormalities are found by the service engineer during service and maintenance
and these are not repairable, this information should be reported to the owner/end-user of the installa-
tion. Also the owner/end-user should be advised how to fix these defects and these defects should be
reported in the service report / log file of the water heater.
During service and maintenance the gas, supply air, flue gas and condensate connections are discon-
nected, checked and replaced. Make sure that all these components are mounted correctly before
commissioning the water heater again.
Mounting the burner door correctly back onto the heat
exchanger:
IMPORTANT:
Before mounting the burner door, make sure that its gas-
kets and insulation are in excellent shape.
If any signs of damage or ageing are present, these parts
must be replaced.
The burner door must be mounted back on the heat ex-
changer as follows:
- Place the burner door with its holes over the six threaded
studs.
Careful! When handling too rough or misplacing the holes
over the threaded studs, the burner door insulation and/or
gaskets can be damaged.
Assure yourself that the door is well positioned with re-
spect to the threaded studs, before pushing it onto the
exchanger.
- Now keep the burner door firmly in place by pushing the
gas/air nose with one hand at the middle at point
A
.
- Then turn-tighten the flange nuts with the other hand as
far as possible onto the threaded studs.
Now the burner door is in place and the nuts can be tight-
ened with a torque key.
-
Tighten the nuts in the order given in the picture
below.
-
The specified torque value for tightening the burner
door flange nuts is
8 Nm.
tighten in given order
torque value = 8 Nm
USER INSTRUCTIONS
After installing and commissioning of the water heater demonstrate the operation of the entire DHW system to the
end-user. The user should be made familiar with all safety precautions of the water heater and the installation. The
user should be instructed that service and maintenance of the water heater is required every twelve months.
Regular service and maintenance is essential for a safe and proper operation of the water heater. Hand over the
documents that are supplied with the water heater.
