Clock Natural Gas Meter; Check Orifice Size - Viessmann Vitodens 200 Start-Up/Service Instructions

Start-up and Service

Clock Natural Gas Meter

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.
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.

Check Orifice Size

14
For example:
A Vitodens 200-W 8-32 boiler (124 000 Btu/h input)
requires 290 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,
36 000/290 x 1000 = 124 000 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 m3 natural gas.
1. Remove burner cover panel (if still installed) as per
the removal and reinstallation instructions on page
6 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 44 of
this manual for information on gas orifices.
IMPORTANT
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 6-24C
Natural gas E24
Liquid propane P24
Vitodens 200 WB2 Service
WB2 6-24 WB2 8-32
E24 E32
P24 P32