Hyco powerflow series - Troubleshooting

7. Troubleshooting
Symptom Cause Remedy
Unit not heating and Thermal cut-out has Reset thermal cut-out
display not working. operated. (see section 5 Maintenance).
If problem persists, contact
hyco for further advice.
Pressure relief valve Expanding hot water. Check and alter expansion
discharging on heating vessel charge (see section 5
cycle. maintenance)
Water too hot. Thermostat setting Adjust thermostat down
too high. (see section 4 Operation)
Pressure relief valve Pressure too high or Change pressure reducing
discharges constantly. relief valve faulty. valve/change pressure relief
valve.
Water not heating but Faulty component(s) Check heating element with
display working. multi meter, if faulty replace
element (see section 5
maintenance). If element ok
then change PCB and thermisto r
contact hyco for further advice.
No/limited water flow. Obstruction in Check flow from pressure
pipework or the relief valve, if limited flow then
heater inlet/outlet. problem could be pressure
reducing valve. Inspect and
clean pressure reducing valve
(see section 5 maintenance).
If pressure relief valve flows
well then check the heater
for limescale issue (see
section 5 maintenance).
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