OSO 20 RD User Manual

-14-
OSO FAULT FINDING GUIDE
Excessive Hot water from taps
If in doubt at any stage you must consult a qualified electrician
Hot water from taps is cold
If problem still persists
contact a competent
engineer / plumber
Are immersion
heaters switched
on
Switch on
immersion
heaters
Has immersion
heater thermal
cut-out operated?
Check and
reset
button
Is the
programmer set to
central heating or
not switched on
Check and
set to hot
water
programme.
Is the
motorised
valve
operating
correctly?
Check wiring
or plumbing
connections
Check and
reset
button
Has
cylinder
thermal
cut-out
operated?
Is the boiler
working?
YES NO
NO
YES
NO
YES
YES
YES YES
NO
DDIIRREECCTT IINNDDIIRREECCTT
Cylinder Thermostat
set to high
Connect wiring as
per instructions
Faulty
thermostat
replace
Check wiring
on cylinder
thermostat
Wiring Fault
Seek advice
from
electrician
Is Thermostat wired
as per layouts for
“S” or “Y” plan
installation
Is 2-port motorised
valve closing when
cylinder reaches
temperature?
Check cylinder
thermostat is switching
on & off with
programmer & hot water
on
Reduce
Temperature setting
YES
NO
NO
YES
NO
NO
YES
YES

OSO 20 RD Specifications

General

Brand	OSO
Model	20 RD
Category	Water Heater
Language	English