Start-Up; Filling The Heating System - Viessmann Vitocrossal 300 Series Service Instructions Manual

Start-up

Filling the Heating System

10
Vitocrossal 300 CU3A 26 to 199 Service
CAUTION
Unsuitable fill water increases the level of deposits and
corrosion, and may lead to damage to the equipment.
H Thoroughly flush the entire heating system prior to
filling with water.
H Only use water of potable quality.
H The water will have to be softened if it is harder than
8.77 grains / 150 ppm total dissolved solids.
H Inhibitors or antifreeze additives suitable for heating
systems may be added manually.
1. Check the pre-charge pressure of the diaphragm
expansion vessel when the system is still cold.
Note: If the pre-charge pressure of the diaphragm
expansion vessel is lower than the static pressure
of the system, top up with nitrogen until the
precharge pressure 1.5 to 3 psi (0.1 to 0.2 bar)
is higher than the static system pressure.
The static pressure corresponds to the static head.
2. Close the gas shutoff valve.
3. Open any installed shutoff valves.
4. Fill the heating system with water and vent it, until
the fill pressure 1.5 to 3 psi (0.1 to 0.2 bar) is higher
than the pre-charge pressure of the diaphragm
expansion vessel using the boiler drain/fill valve A.
Max. operating pressure: ........................... 30 psi (2 bar)
Min. operating pressure: ........................... 14 psi (1 bar)
Pressure relief valve: ................................ 30 psi (2 bar)
5. Mark the set pressure at temperature and pressure
gauge B.
6. Return the shutoff valves to their operating position.
7. Close boiler drain/fill valve A.