13
7.0 FAULT FINDING
Disconnect the electrical supply before removing the terminal cover. It is
recommended that any service operations on the heater are carried out by
a competent person.
FAULT
POSSIBLE CAUSES
ACTION
Water not heating 1. Electrical supply fault Check electrical supply
2. Thermal cut-out tripped Check cut-out, if operated,
reset and check thermostat
operation. If necessary replace
thermostat/thermal cut-out
(see Wiring Diagram Fig. 05, page 8)
3. Thermostat fault
Check thermostat operation.
Replace if necessary.
Discharge of water from Excessive mains water
Fit Expansion vessel, check valve
pressure relief valve pressure
and pressure reducing valve.
Discharge of water from 1. Expansion in mains not Fit Expansion vessel and check
pressure relief valve possible. valve (see IMPORTANT
(intermittently).
INSTALLATION POINTS SECTION 3)
2. Mains pressure exceeds Fit Expansion vessel, check valve
0.41 Mpa (4.1 bar) and pressure reducing valve.
3. Pressure Relief Valve Fault Replace Pressure Relief Valve
4. Loss of pressure from Check and, if necessary,
Expansion Vessel
re-charge Expansion Vessel
pre-charge pressure
(see section 6.1.12)
Discharge of water from Thermostat and
Replace thermostats and
Temperature/Pressure thermal cut out fault
thermal cut outs
relief valve and/or
water/steam from
pressure relief valve
No water flow
1. Inlet valves incorrectly
Check all valves are correctly
fitted
installed in accordance with
flow direction arrows
2. Mains water supply not Check mains water supply
turned on
is on
3. Blockage in main water
Check for obstructions. If
supply
pressure reducing valve with
strainer is fitted, check strainer is
not blocked
"Milky water"
Oxygenated water
Water from a pressurised
system releases oxygen
bubbles when flowing. The
milkiness will disapear
after a short while
