Fault Finding - Heatrae Sadia MULTIPOINT 75 Fitting Instructions And User Manual

8.8 Remove any loose scale from the container. Carefully clean off any
scale from the element and thermostat pocket. DO NOT clean scale
from interior container walls.
8.9 Re-assemble the element plate assembly fitting a new sealing gasket.
Rewire the unit with reference to Figure 4 (wiring diagram).
8.10 Repeat this for both element plate assemblies.
8.11 Re-commission the unit following the INSTALLATION and
COMMISSIONING instructions.
Figure 6. Removal of expansion vessel for maintenance puproses.
The Temperature/Pressure Relief Valves and the Pressure (Expansion
Relief Valve should be regularly operated to remove lime deposits and
varify that it is not blocked.
8.12 Manually operate the valves by twisting the cap. Ensure water flows
freely from the valves and through the discharge pipes (NOTE: the
water discharged may be very hot). Ensure the valves reseat correctly
when released.
8.13 Clean the strainer incorporated in the Pressure Reducing Valve.
To inspect and clean the strainer turn off the mains water supply to the
heater and open a hot tap to relieve the system pressure. Unscrew the
black cap from the Pressure Reducing Valve and remove. The strainer
will be removed with the cap. Wash any particulate matter from
the strainer under clean running water. Replace the cap assembly
ensuring the sealing ring is correctly fitted. Do not use any other type
of sealant. Close hot tap, open mains stop cock and check for leaks.
The Expansion Vessel should have a precharge pressure of 3.5 bar
(51p.s.i.).
This can reduce over time and eventually require re-charging. To do
this:
8.14 Turn off water supply to the unit; open a hot tap to relieve system
pressure.
8.15 Switch off and disconnect electrical supply to water heater.
8.16 Remove the terminal cover by removing the five supporting screws
holding it in place.
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8.17 Remove dust cap from top of Expansion Vessel.
8.18 Check pre-charge pressure using a tyre pressure gauge. If the
pressure
is lower than 3.5 bar (51 p.s.i.) it should be recharged using a tyre
pump (Schraeder Valve type). DO NOT OVER CHARGE.
8.19 Re-check pressure and when correct replace dust cap.
8.20 Turn on mains water supply and close hot tap.

9.0 FAULT FINDING

The Multipoint unit should give trouble free operation, however should a
problem occur, the tables below should enable most faults to be identified
with ease.
Fault Finding should be carried out by a competent person and any re-
placement parts used should be authorised Heatrae spare parts.
FAULT POSSIBLE CAUSES
Water not heating Electrical supply fault
Thermal cut out tripped
Thermostat setting too
low or faulty.
Discharge of water from Excessive mains water
pressure relief valve pressure
(continuously).
Expansion relief valve
fault
Discharge of water from Loss of pressure from
pressure relief valve Expansion vessel
(intermittently).
Discharge of water from Thermostat and
Temperature/Pressure thermal cut out fault
relief valve and/or
water/steam from
pressure relief valve
No water flow Product incorrectly
Installed
Mains water supply
not turned on.
Blockage in main water
supply
"Milky water" Oxygenated water
ACTION
Check electrical supply
Check cut outs. If they have
operated then reset them.
If necessary replace them.
Check thermostats and if
necessary replace them.
Check thermostat setting.
Replace if necessary.
Check pressure from
Pressure reducing valve.
Replace if greater than
3.5 bar (51psi)
Replace expansion relief
valve.
Check and if necessary
re charge expansion vessel
pre charge pressure.
Replace thermostats and
thermal cut outs
Check inlet and outlet
connections are correct.
Check valves are installed
in accordance with flow
direction arrows.
Check mains water supply
is turned on.
Check mains water supply
for obstructions.
Check Expansion relief valve.
Water from a pressurised
system releases oxygen
bubbles when flowing. The
milkiness will disapear
after a short while.
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