Check Diaphragm Expansion Tank And System Pressure; Check Functioning Of Safety Valves - Viessmann Vitodens 100-W WB1B Series Installation And Service Instructions Manual

Vitodens 100-W, WB1B Installation & Service
Steps
(continued)
Start-up and Maintenance
Start-up and Maintenance
Start-up and Maintenance

20. Check diaphragm expansion tank and system pressure

Perform check on the system when cold.
1. Drain boiler/system and reduce pressure until the
manometer reading is "0".
2. If the nitrogen pressure of the pre-charged expansion
tank is less than the static pressure of the system,
inflate membrane pressure to slightly exceed pressure
of system.
The static pressure required at the tank is based upon
the static height of the system. The system fill
pressure value must be equal to the expansion tank
pressure value at approx. 60º F (15.6º C).
Note: Static head of 33 ft. (10 m) (distance
3. Top up with water until filling pressure is higher than
the inlet pressure of the diaphragm expansion tank.
Note: With the system cold, the filling pressure must
4. When starting up the system for the first time, mark
this value as the minimum filling pressure on the
manometer.
Note: A lower manometer reading usually indicates

21. Check functioning of safety valves

Ensure proper operation of low water cut-off(s)
(if applicable), pressure relief valve, and pump(s).
Check pressure gage, air vent and pressure relief valve.
Ensure that pressure relief valve does not leak and that it
operates in accordance with information provided by the
original manufacturer.
Flush float water type low water cut-offs (if used).
Follow local regulations with respect to backflow preventers.
If oil-lubricated pumps are used, ensure proper lubrication.
If motorized zone valves are used, refer to maintenance
instructions provided with zone valves.
Start-up, Inspection and Maintenance
between boiler and topmost heat emitter
surface) corresponds to a static pressure
of 1 bar (15 psig).
be approx. 3 psig higher than the static pressure.
Max. boiler operating pressure............45 psig
Min. boiler operating pressure....14 to 23 psig
Pressure relief valve.......................... 30 psig
loss of water due to leakage. All leaks must
be repaired.
Refer to maintenance instructions supplied
with low water cut-offs, pumps, etc.
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