Check All Connections And Sensor Well For Leaks; Check Proper Operation Of Low Water Cut-Off; Check Proper Expansion Tank And System Pressures - Viessmann VITOCROSSAL 300 Service Instructions Manual

Inspection and Maintenance

Check all Connections and Sensor Well for Leaks

A

Check Proper Operation of Low Water Cut-off

Check Proper Expansion Tank and System Pressures

CAUTION
Carry out all check in accordance with the expansion tank
manufacturer's instructions. Limit pressure fluctuations
to the lowest possible differential. Cyclical pressure
fluctuations and greater pressure differentials indicate a
system fault. Immediately remedy such faults, otherwise
other heating system components may become faulty.
CAUTION
Damage on boiler or other system components may
result if these recommendations are not followed.
16
Only open the heating water connections after the boiler
B
has been depressurized. Only drain the boiler with a
vacuum pump when the boiler air vent valve is open.
1. Remove cap A from the back of the boiler.
2. Check sensor well B for leaks.
3. Reinstall cap.
The diaphragm expansion tank must be able to hold the
heating water expansion volume inside the boiler, and
must be properly sized for the system.
This diaphragm expansion vessel reduces the frequency
and severity of pressure fluctuations; the service life
of the circulating pump is improved and therefore
the operational reliability and service life of system
components increased.
Carry out this test on a cold system.
1. Drain system or close cap valve on the diaphragm
2. Cold static 60°F (15.5°C) water fill pressure must
Vitocrossal 300, CT3 Series Service
CAUTION
Observe the detailed test instructions by the
manufacturer.
Reference expansion tank manufacturer's
instructions.
IMPORTANT
IMPORTANT
expansion tank and reduce the pressure until the
pressure gage indicates "0".
equal diaphragm expansion tank pressure.