Viessmann WB2-44 - Page 17

Initial Start-up and Service
17
Steps (continued)
9. Clock natural gas meter
Initial start-up Service
Clock natural gas meter to verify input
1. Ensure all other gas equipment
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.
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
t=TIME (sec.) for 1 ft.
3
INPUT=(3600 x .01 x 1000 x 35.31)÷T
where
T = TIME (sec.) for .01 m
3
natural gas
A boiler underfired by 5% is
acceptable. Do not overfire the boiler.
10. Check orifice size
Service
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.
See section entitled “Technical Data”
on page 46 of this manual for
information on gas orifices.
Place O-ring E in groove on new gas
orifice B.
5. Tighten screws A. Tighten to a torque of 1.1 lb.ft./
1.5 Nm.
6. Check all gas connections for leaks
with an approved leak test solution.
Overview of orifices
Boiler model
WB2 11-44 WB2 15-60
Natural gas E44 E60
Liquid propane P44 P60
5285 961 v1.3
IMPORTANT
Always contact your gas utility to
obtain the correct heating value before
clocking the meter.
CAUTION
ACB
E
IMPORTANT
Stamped identification code