The LEDs on the DuoHeat storage heater might flash for a number of reasons.
- If there has been an interruption to the mains supply or a power surge.
- If there has been work carried out to the heater (ie powering up the heater with the front cover removed).
- If there is a fault with the heater or one of the temperature sensors.
- If the peak Line & Neutral connections are accidentally cross wired (ie Live to Neutral and Neutral to Live on the wall switch to the heater) then this will make the display flash until that issue is corrected and the diagnostic feature is run again to clear the error. On existing installations, this is unlikely unless recent electrical work has been carried out.
There is an onboard diagnostic feature on the Duo-N heaters. to access it, follow this video guide:
When in diagnostic mode:
If the 1st Red LED flashes: Room temperature sensor fault. Room sensor should be clipped under the heater and connected to the Charge Controller. If the Charge Controller has failed, at this point a new heater would be needed as the Charge Controller is now NLA. The DuoHeat has been out of production for several years and some of the components are no longer made.
If the 2nd Red LED flashes: Core temperature sensor fault. Core sensor is part of the main Charge Controller and if this has failed, at this point a new heater would be needed as the Charge Controller is now NLA. The DuoHeat has been out of production for several and some of the components are no longer made.
If the 3rd Red LED flashes: Front panel temperature sensor fault. Make sure the front radiant panel is connected to the heater and re-run the diagnostic test a second time to confirm the front panel is correctly re-attached.
If the 8th or 9th LED flashes: All is OK. Press the Minus button to exit the self diagnostic test and the display should stop flashing, indicating normal operation.
In any case to exit diagnostic mode, press the minus button.
To re-run the diagnostic feature if the LEDs are not flashing follow this video guide:
More information on how to use the DuoHeat storage heaters can be found here.
Note the DuoHeat range of heater are now discontinued and there are limited spare parts.
Applicable to: DUO300N DUO400N DUO500N
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