Troubleshooting; Fault Finding - Heatrae Sadia Megaflo Eco SystemFit 145sf Instructions Manual

10. Troubleshooting

WARNING
Do not tamper with any of the safety valves
or controls supplied with the cylinder as this
will invalidate any guarantee.

10.1 Fault finding

Important
`
After servicing, complete the relevant Service Interval
Record section of the Benchmark Checklist located
on pages 32 and 33 of this document.
` Servicing should only be carried out by competent
persons in the installation and maintenance of
unvented water heating systems.
` Any spare parts used MUST be authorised parts.
` Disconnect the electrical supply before removing any
electrical equipment covers.
`
NEVER bypass any thermal controls or operate system
without the necessary safety valves.
Fault
No hot water flow
Cold water combination valve incorrectly
Direct immersion heater not switched on
Water from hot tap
is cold
Water discharges
from expansion
valve
Water discharges
from T&P relief valve
Milky water
Table 5: Fault finding chart
26
Possible Cause
Mains water supply off
Strainer blocked
fitted
Direct immersion heater thermal cut-out
has operated
Indirect programmer set to central
heating only
Indirect boiler not working
Indirect thermal cut-out has operated
Indirect motorised valve not connected
correctly
Intermittently
Air volume in product has reduced
Continually
Cold water combination valve pressure
reducer not working correctly.
Expansion valve seat damaged
Thermal control failure
CAUTION: Water will be very hot!
Oxygenated water
` Water contained in the cylinder may be very hot,
especially following a thermal control failure. Caution
must be taken when drawing water from the unit.
The fault finding chart (table 5, below) will enable
operational faults to be identified and their possible
causes rectified. Any work carried out on the unvented
water heater and its associated controls MUST be carried
out by a competent installer for unvented water heating
systems. In case of doubt contact
Spare Parts
A full range of spare parts are available for the
cylinder range (table 6, page 27). Refer to the technical
data label on the unit to identify the model installed and
ensure the correct part is ordered. You will need to quote
the serial number, which is printed on the data label.
Remedy
Check and open stop cock
Turn off water supply. Remove strainer and clean
Check and refit as required
Check and switch on
Check, reset by pushing button on thermostat
Check, set to domestic hot water programme
Check boiler operation. If fault is suspected
consult boiler manufacturer's instructions
Check, reset by pushing button on thermostat.
Check operation of indirect thermostat
Check wiring and/or plumbing connections to
motorised valve
See Page 24 for re-charging of the air volume
Check pressure from cold water combination
valve. If greater than 3bar replace pressure
reducing valve cartridge.
Remove expansion valve cartridge, check
condition of seat. If necessary fit new expansion
valve
Switch off power to immersion heater(s) and shut
down boiler.
DO NOT turn off water supply. When discharge
stops check all thermal controls, replace if faulty
Water from a pressurised system releases oxygen
bubbles when flowing. The milkiness will
disappear after a short while
service support.