Adjusting The Burner - Viessmann Vitoradial 300-T VR3 Service Instructions For Contractors

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.
Rated combus- Pressure drop on the hot gas
tion heating out- side
put Q
n
kW
97
124
151
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.
Rated combustion
heating output Q
n
kW
97
124
151
194
254
323
Operation with burner load
The minimum system temperatures (flow/return) are
50/35 °C for oil operation and 60/45 °C for gas opera-
tion.
Pa mbar
55 0.55
80 0.80
120 1.20
60 %
≥
Minimum heating output to
be set (burner stage 1)
40 % and < 60 %
≥
Commissioning, inspection, maintenance
Rated combus-
tion heating out-
put Q
n
kW
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.
The base load stage requires a minimum flue gas tem-
perature, the value of which is subject to the design of
the flue system.
kW
58
74
91
116
152
194
Pressure drop on the hot gas
side
Pa
180
240
275
mbar
1.80
2.40
2.75
19