Checking The Condensate Drain And The Neutralising System (If Installed); Closing The Boiler Casing; Checking The Expansion Vessel; Checking The Water Quality - Viessmann Vitocrossal CRU 800 Service Instructions For Contractors

Commissioning, inspection, maintenance

Checking the condensate drain and the neutralising system (if installed)

1. Fill the combustion chamber with water.
Note
The water must flow from the condensate drain
pipe without backing up.
If necessary, clean the condensate drain pipe
again.
2. Check the function of the neutralising system.
Neutralising system operating instructions

Closing the boiler casing

Close the boiler again in reverse order to Fig. 10 on
page 19.

Checking the expansion vessel

Note
Observe the manufacturer's instructions for the expan-
sion vessel.
Carry out this test on a cold system.
1. Drain the system until the pressure gauge indi-
cates "0" or close the cap valve on the expansion
vessel and reduce the pressure in the expansion
vessel.
2. If the expansion vessel pre-charge pressure is
lower than the static system pressure, top up with
nitrogen. Top up with nitrogen until the pre-charge
pressure is 0.1 to 0.2 bar (10 to 20 kPa) higher.

Checking the water quality

Enter the amount of top-up water, the total hardness
and the pH value in the tables on page 61.
For water quality requirements: See page 59.

Checking the gaskets on the flue gas side

Danger
Leaking or blocked flue systems, or an inade-
quate supply of combustion air, can cause life
threatening poisoning from carbon monoxide in
the flue gas.
Ensure the flue system is in good working order.
Vents for supplying combustion air must be non-
sealable.
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3. If necessary, clean the neutralising system in
accordance with the manufacturer's instructions.
Neutralising system operating instructions
Note
Neutralising medium from Viessmann Werke
GmbH & Co. KG, part no. 9521702.
4. Check entire condensate drain pipe for leaks.
3. Top up with water. The charge pressure of the
cooled system must be 0.1 to 0.2 bar (10 to
20 kPa) higher than the pre-charge pressure of the
expansion vessel.
Permiss. operating pressure: 6 bar/0.6 MPa