56
Henrad CC FF
- Installation
FAULT FINDING
86 Low system pressure indicated on pressure gauge.
Check the pressure on the gauge on the boiler
control panel.
Is it reading below 0.5 bar ?
Is this a new
installation ?
NO
Fill and repressurise the system but leave
the boiler OFF.
Check boiler heat exchanger, all CH
pipework and radiators for leaks, including
loft or underfloor pipes where used.
Was a leak found ?
YES
Increase the system pressure, if necessary,
to 1 bar.
Does the boiler now operate ?
Has it
recently
been
extended ?
Fill and
pressurise the
system
Add extra
expansion
volume
YES
YES
NO
Are there any obvious leaks ?
Fill and
repressurise the
system
Has it been partly
drained to move a
radiator ?
NO
NO
YES
YES
Is volume of the system
consistent with volume of
the expansion vessel(s)
fitted ?
NO
NO
NO
YES
NO
Check discharge pipe from the
safety valve (this may well be
outside the building).
Has it been discharging water ?
NO
NO
YES
Is the safety valve free
from foreign matter,
correctly set and in the
closed position ?
NO
YES
Replace safety valve and
refill / repressurise
Fire the boiler up on CH.
Observe pressure gauge as
system reaches
temperature.
Does pressure reach (or
exceed) 2.5 bars ?
YES
Recheck for leaks on
pipes and radiators
Unscrew the Schrader valve from expansion vessel
and fit new valve (e.g. from car tyre sales outlet).
Repressurise expansion vessel to 1 bar (15 lb/in
2
).
Does vessel pressure hold up ?
Fill and
repressurise
system
YES
Replace
expansion
vessel
Check that the wiring to the low water
pressure switch terminals 1, 2 and 3
corresponds with that shown in the wiring
diagrams.
Was an error found ?
Is there continuity between terminals 1
and 3 on the low water pressure switch ?
NO
NO
NO
Change
pressure
switch
NO
Use a drain cock (
not the safety valve) to release all
pressure on the boiler pressure gauge. Remove cap
from the air valve on the expansion vessel.
Measure air pressure with a car tyre pressure gauge.
Is it at least 0.8 bar (12 lb/in
2
) ?
Check for
obstruction
in the pipe
feeding the
expansion
vessel
Clear and re-adjust the valve.
Repressurise the system
F
AUL
T FINDING
Summary of Contents for CC 100 FF
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