15.1.5Block 67
a temperature difference has been detected between the supply and return sensor whilst the burner is not in operation. After the average DT has disappeared, the block will disappear.
check the sensors NTC 1 and NTC 2
check the supply and return sensor for the resistance value and replace the defective sensor
check the installation for any external heat source and rectify this
Installation & Servicing Instructions Rinnai
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