Viessmann VITODENS 200 Start-Up And Service Instructions page 17

Steps
(continued)
I S
nitial start-up ervice
Clock natural gas meter to verify input
Ensure all other gas equipment
1.
served by the meter is turned off
during timing of gas input to the
Vitodens 200 boiler.
2.Measure the time in seconds it takes
for the boiler to use 10 cu. ft. of
gas. Divide 3600 x 10 by the
number of seconds and you get the
number of cu. ft. of gas used per
hour. Multiply this number by the
heating value of the gas to obtain
Btu per hour input.
S
ervice
E
B A C
Stamped identification code
9. Clock natural gas meter
For example:
A Vitodens 200, WB2 11-44 boiler
(172 000 Btu/h input) requires 209
seconds to use 10 cu. ft. of natural
gas. After contacting the local utility,
you will find the heating value is
1000 Btu per cu. ft.
Therefore,
3600 x 10/209 x 1000 ≅ 172 000
Btu/h input.
Therefore, the boiler input is correct.
Burner input formulas
(for low altitude only):
INPUT=(3600 t) x 1000 where
÷
3
t=TIME (sec.) for 1 ft.
INPUT=(
3600 x .01 x 1000 x 35.31)
where
3
T = TIME (sec.) for .01 m
10. Check orifice size
1. Remove burner cover panel (if still
installed) as per the removal and
reinstallation instructions on page 7
in this manual, and reinstall panel
upon completion of service work.
2. Loosen screws A and take the gas
orifice holder C out of the fitting.
3. Read orifice size stamped on the
orifice body and cross-reference to
table below. If wrong orifice is
installed, proceed to next step.
4. Push the gas orifice B sideways out
of the gas orifice holder C. Snap
new and correct gas orifice into gas
orifice holder and push into the gas
train.
5. Tighten screws A.
6. Check all gas connections for leaks
with an approved leak test solution.
Overview of orifices
Boiler model WB2 11-44
Natural gas E44
Liquid propane P44
Initial Start-up and Service
IMPORTANT
A boiler underfired by 5% is
acceptable. Do not overfire the boiler.
CAUTION
Always contact your gas utility to
obtain the correct heating value before
clocking the meter.
÷
T
natural gas
See section entitled "Technical Data"
on page 46 of this manual for
information on gas orifices.
IMPORTANT
Place O-ring E in groove on new gas
orifice B.
Tighten to a torque of 1.1 lb.ft./
1.5 Nm.
WB2 15-60
E60
P60
17