Restarting The System; Adjusting The Burner - Viessmann Vitoradial 300-T Service Instructions Manual

Commissioning, inspection, maintenance

Restarting the system

Adjusting the burner

Burner service instructions or separate docu-
mentation by the burner manufacturer
Adjust the maximum oil throughput of the burner to the
rated boiler heating output.
Determining the pressure drop on the hot gas side
Determine the pressure drop on the hot gas side
before and after cleaning. See chapter "Cleaning the
flue outlet and heat exchanger".
At full load, measure the pressure difference between
the test connector on the inspection nipple and the flue
draught. After correct cleaning, the pressure drop on
the hot gas side should approximately correspond to
the specified values.
Rated combus- Pressure drop on the hot gas
tion heating out- side
put Q
n
kW
97
124
Partial load operation
Set the minimum heating output for the base load
stage according to the conditions of the flue system.
Note that the flue system must be suitable for the low
flue gas temperatures that may occur.
In the case of frequent cycling in standby mode and for
partial loads below 40 % we recommend the following:
■ Insulate the flue gas collector.
■ Install a motorised flue gas damper.
■ Set the minimum runtime for the boiler to 10 minutes.
Operation with burner load
The minimum boiler water temperature for oil operation
is 40°C.
To protect the boiler, the minimum heating output at
the base load stage is set to 60 % of rated heating out-
put.
20
Pa mbar
55 0.55
80 0.80
60 %
≥
Rated combus- Pressure drop on the hot gas
tion heating out- side
put Q
n
kW
151
194
254
323
To protect the system against dew point corrosion,
burner stage 2 (full heating output) must be set to the
rated boiler heating output. It must remain switched on,
even during the summer months (burner stage 2 on
constant standby).
This extends the service life and reduces running
costs.
Rated combustion
heating output Q
n
kW
97
124
151
194
254
323
The base load stage requires a minimum flue gas tem-
perature, the value of which is subject to the design of
the flue system.
Pa mbar
120 1.20
180 1.80
240 2.40
275 2.75
Minimum heating output to
be set (burner stage 1)
kW
58
74
91
116
152
194