Troubleshooting; Fault Finding - Heatrae Sadia Megaflo Eco 70i 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 35 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 1. Mains water supply off.
2. Strainer blocked.
3. Cold water combination valve
incorrectly fitted.
Water from hot taps 1. Back up immersion heater not
is cold switched on.
2. Back up immersion heater
thermal cut-out has tripped.
3. Indirect programmer set to
central heating only.
4. Indirect boiler not working.
5. Indirect thermal cut-out has
tripped.
6. Indirect motorised valve not
connected correctly.
Water discharges from 1. Intermittently. Air volume in the
expansion relief valve cylinder has reduced
2. Continually. 3 bar pressure
reducing valve is not working
correctly.
3. Continually. Expansion valve seat
damaged.
Water discharges 1. Air volume in the cylinder has
from the T&P valve reduced
intermittently
2. 8 bar expansion relief valve
faulty.
Water discharges 1. Thermal control failure. Note
from the T&P valve water will be very hot.
continually
Milky water 1 Oxygenated water.
Table 7: Fault finding chart
Possible cause
1. Check and open stop cock.
2. Turn off water supply. Remove strainer and clean ( see page
31).
3. Check and refit as required.
1. Check and switch on.
2. Check. Reset by pushing button (Figure 14, page 20).
3. Check. Set domestic to a hot water programme.
4. Check boiler operation. If fault is suspected consult boiler
manufacturers instructions.
5. Check. Reset by pushing button. Check operation of indirect
thermostat (Figure 14, page 20).
6. Check wiring and/or plumbing connections to motorised
valve (see Figures 16&17, page 21).
1. See page 26 for details on how to test and recharge.
2. Check pressure from 3 bar pressure reducing valve. If greater
than 3 bar replace pressure reducing cartridge.
3. Remove expansion relief cartridge from 8 bar pressure relief
valve and check seating, if necessary fit new cartridge.
1. See page 26 for details on how to test and recharge.
2. Check valve and replace if necessary
1. Switch off power supply to immersion heater(s) and shut
down the boiler. DO NOT turn off the water supply. When
discharge stops check all thermal controls, replace if faulty.
1. Water from a pressurised system releases oxygen bubbles
when flowing. The milkiness will disappear after a short while.
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 7, 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
support.
Spare Parts
A full range of spare parts are available for the
cylinder range (Table 8, page 29). 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
service
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