Fault Finding - Vent-Axia HR400 Installation And Servicing Instructions

Fault Cause
1. Unit will not Electrical Fault
operate when
switched on.
2. Unit will only Transformer
operate on boost damaged
or
wiring fault
3. Unit trips out Water build up in
unit
Remedy Fault
Switch off the mains 4. Low airflows at
electrical supply to terminal devices
the unit and;
a) check power
supply to switched
fused spur.
or
b) check fuse
or
c) check electrical
connector at unit
or
d) check wiring to
VCON77 controller
5. Air flow failure
or
e) check wiring to
control switch
(NBSW, PCSW or
HS6)
Switch off the mains
electrical supply to
the unit and;
a) check wiring to
6. Noise at air
control switch
terminal devices
(NBSW, PCSW or
HS6)
or
b) disconnect wiring
to control switch and
test operation of
switch with
Multitester. Replace
switch if faulty
or
c) test output of
VCON77 controller
and replace if faulty.
a) check that unit is
inclined to drain
connection
or
b) check condensate
pipework for
7. Unit noisy
blockage
or
c) check for earth
fault on wiring to
controller / control
switch / unit
or
d) check for motor
thermal fuse trip by
switching off unit,
allowing to stand for
approx. 45 minutes
then restarting unit

7.0 Fault Finding

Cause
1) VCON77
controller set at
incorrect voltage
2) Flexible silencer
crushed or collapsed
internally
3) Excess fouling of
heat exchanger
4) Fresh air /
exhaust air devices
blocked
5) Filter (if fitted)
blocked
Fan / fans stopped
1) excessive airflow
2) ducting
components (QTET)
connected directly
over air valve
3) Fan / fans bearing
failure
1) unit not located
on acoustic mat
2) VCON77
controller set at
incorrect voltage
3) Fan / fans bearing
failure
Remedy
1) Increase voltage
setting at VCON77
controller
2) Replace flexible
silencer.
3) Service the unit
4) Disconnect
ducting and remove
debris
5) Replace filter
media
Switch off the mains
electrical supply to
the unit and
a) remove access
panel and heat
exchanger
b) check fans for
free operation
c) replace if seized
1) check airflow rate
complies with
commissioning data
2) modify ducting
arrangement to
relocate QTET a
minimum of 2.5
diameters from air
valve.
3) switch off the
mains electrical
supply and remove
access panel and
heat exchanger.
Check fans
individually for
evidence of bearing
noise, replace if
considered
excessive.
1) Lift unit and fit
acoustic mat
2) reduce voltage
setting at VCON77
controller, ensuring
compliance with
commissioning data
3) repeat as 3 of
previous remedy
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