Checking The Diaphragm Expansion Vessel And System Pressure - Viessmann VITODENS 111-W Installation And Service Instructions Manual

Further details regarding the individual steps
4. Fit electrical cables to fan motor D,
gas train E and ignition unit F.
5. Reopen gas supply and switch on
power supply.
6. Check the gas connections for tight-
ness.
Danger
Escaping gas leads to a risk of
explosion.
Check the fitting for gas tight-
ness.
!
Please note
The use of leak detection
spray can result in faulty oper-
ation.
Leak detection spray must not
come into contact with electri-
cal contacts or seal the dia-
phragm opening on the gas
valve.

Checking the diaphragm expansion vessel and system pressure

Note
The diaphragm expansion vessel can
lose some charge pressure over time.
When the boiler heats up, the pressure
gauge will indicate a higher pressure of
2 or 3 bar. The safety valve too can
respond and discharge excess pres-
sure.
Check whether the installed diaphragm
expansion vessel on the heating water
side is adequate for the system water
volume.
Carry out this check on a cold system.
Commissioning, inspection, maintenance
(cont.)
7. Push grommet C up again.
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