32
Issue 1 06/02/20
9
Troubleshooting
Fault
No hot water flow
Water from hot tap is cold
Water discharges from
expansion valve
Water discharges from
T&P relief valve
Milky water
Possible Cause
Mains supply off
Strainer blocked
Cold water combination valve incorrectly
fitted
Indirect motorised valve fault
Pump failure
Indirect programmer set to central heating
only
Indirect heat source not working
Indirect thermal cut-out has operated
Indirect motorised valve not connected
correctly
Intermittently Expansion vessel charge
pressure has reduced, or set too high
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
Remedy
Check and open stop cock
Turn off water supply. Remove strainer and
clean
Check and refit as required
Check, operation of valve
Check, pump operation
Check, set to domestic hot water programme
Check heat source operation. If fault is
suspected consult heat source 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 Maintenance section (p.29) for re-
charging of expansion vessel procedure
Check pressure from cold water combination
valve. If greater than 6 bar replace pressure
reducing valve.
Remove expansion valve, check condition of
seat. If necessary fit new expansion valve
Switch off power to heater(s) and shut down
heat source.
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