FAQ & Troubleshooting

FAQ

This process varies between different OSO product series, see user manual for instructions.
If the manual is missing, contact OSO Hotwater.

The temperature inside the water heater can be adjusted by turning the internal thermostat up or down:
1. Turn off power supply to the water heater
2. Remove electrical junction box cover
3. Adjust the temperature on the thermostat – see user manual
4. Refit the junction box cover before turning power supply back on.

NOTE: It is not recommended to set the temperature below 55°C due to danger of bacterial growth inside the water heater.

Thermostats in OSO products have an emergency cut-off which will activate if the temperature in the water heater gets too high or the water heater is exposed to high power input caused by lightning strikes, power supply surges etc. To reset the thermostat (see manual):
1. Turn off power supply to the water heater
2. Remove electrical junction box cover
3. Press the  ‘RESET’ button on the upper part of the thermostat. A distinct ‘click’ should be heard if the cut-off has been activated.
4. Refit the junction box cover before turning power supply back on.
If the emergency cut-off activates repeatedly without any of the power input problems mentioned above occurring the thermostat might need replacing. Contact authorised installer.

For information for sizing please see PDF below.

Dimensioning

Troubleshooting

Possible cause 1: Excess pressure coming into the property causing pressure reducing valve to fail.

Solution: Add additional pressure reduction valve on cold feed see installation manual. Contact authorised installer.

Possible cause 2: The heaters safety valve is worn or there are particles between the membrane and valve seat due to unclean water.

Solution: try to flush through the  valve with water. Open the valve for about 1 minute. If the valve is still dripping after closing the valve must be replaced. Contact authorised installer.

Possible cause 3: Water leaking from immersion boss

Verify by:
1. Switch off  electrical supply to immersion
2. Unscrew the lid in front of the electrical box
3. Visually check if the leak comes from the heating element.

Solution if YES: change “O” ring seal/ heater. Contact authorised installer.

Possible cause 1: No  power supply to the water heater.
Solution: Verify by:
1. Check the consumer unit for tripped MCB
2. Check double pole switch has no failed

Possible cause 2: The safety thermostat has tripped.
Solution: Press the “RESET” button on the safety thermostat.
1. Disconnect power
2. Disassemble the electric lid with a screwdriver.
3. Press the  “RESET” button.

Possible cause 3: The heating element has failed.
Solution: Replace heating element. Contact authorised installer.

Probable cause is that there is a lot of consumption of hot water in the home.

Solution 1: Change to a larger volume OSO Hotwater heater. Contact authorised installer.

Possible cause 1: The electrical thermostat is set too low.

Solution: adjust the temperature on the thermostat up to 60 or 70°C (see user manual).
1. Disconnect the power supply
2. Remove the electrical junction box cover using a screwdriver.
3. Adjust the temperature on the thermostat.
4. Refit the electrical junction box cover before connecting the power supply.

Probable cause is incorrect wiring or fault in the water heater electrical system.

Solution: Verify by:
1. Turn off power supply to water heater
2. Remove electrical junction box cover
3. Inspect junction box for any visually detectable faults (loose, crossed or overheated wires etc.) if no visible wiring errors replace immersion heater
If any faults are visible or the problem persists, contact authorised electrician. Refit junction box cover.

This is normal if the distance from the water heater to the tap is significant due to water cooling in pipes between use.

Possible solution:
1. Install hot water circulation pipe (pump and extra pipe required – contact installer)

Please contact us with your inquiries, we’re happy to help!

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Switchboard: (+44) 0191 482 0800
Technical support: (+44) 0191 482 7049

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