Unvented hot water cylinder – SCxn…d/i, SCxn…sd/si
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ST0109 – C 05/09
WATER
9 Troubleshooting
Fault
Cause
Solution
A No water
from hot
water
taps
A.1 Stop valve closed
A.2 Strainer blocked
A.3 Pressure reducing valve fitted
against flow
A.1 Open stop valve
A.2 Turn water supply off,
clean strainer and re-
commission
A.3 Re-fit with arrow showing
in direction of flow
B No hot water
B.1 Timer/Programmer not set
correctly
B.2 Auxiliary heating mal function
B.3 Direct heating mal function
B.4 Auxiliary/direct heating high
limit thermostat has tripped
B.1 Set timer/programmer
correctly
B.2 Consult auxiliary heating
system instructions
B.3 Call for qualified person
to check immersion
heater
B.4 Reset limit thermostat(s)
C Intermittent
water dis-
charge
through tun-
dish on
warm-up
C.1 Bubble depleted
C.2 Expansion vessel lost charge
C.1 See commissioning for
creation of bubble
C.2 Check expansion vessel
(see commission-
ing/maintenance), top up
or replace
D Continuous
discharge
D.1 Pressure reducing valve not
working
D.2 Pressure relief or T&P valve
not seating correctly
D.3 Mal function of high limit
thermostat or appliance
D.1 Check pressure after
valve and replace if
faulty
D.2 Manually lift valve once
or twice to clear debris,
otherwise replace
D.3 Check function of ther-
mostats and appliances
E Leakage from
casing
E.1 Compression/threaded joints
not formed correctly
E.1 Re-seal joints with care
F Hot water
from cold tap
F.1 Hot pipe work being routed
adjacent to cold pipe work
F.2 Leaking seal in mixer tap
F.1 Insulate hot pipe work or
re-route
F.2 Replace seals in mixer
tap
G Metallic noise
from system
G.1 Pipe work not sufficiently
supported
G.1 Add extra pipe work fix-
ings