Low Warning
98:1 on Viessmann Vitodens 300-W

Your boiler is having difficulty communicating with the external system that monitors several heating units at once.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Viessmann system numbers (in conjunction with monitoring of several systems via Vitocom 300)

What causes this fault?

This fault occurs when the boiler's main control board loses its digital connection with an external monitoring system like the Vitocom module. It is usually caused by a loose communication cable, a damaged internal coding plug, or a hardware failure within the remote monitoring interface itself.

DIY fix possible

Check that your internet router and hub are plugged in and switched onIdentify if any other system monitors or Vitocom devices have lost powerPress the 'Reset' button on the boiler control panel once

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