BoilerFaultCodesViessmann 80:2 to 80:199 Fault Code
Also written as 802TO80199 — same fault.
The Viessmann 80:2 to 80:199 fault code means: your boiler is waiting for a pre-set delay period to pass before restarting, often caused by a temporary communication gap or a signal issue between internal components.. It appears on 5 Viessmann models in our database.
Technical description: Time delay adjustable from 10s to 995s; 1 step = 5s
What causes the Viessmann 80:2 to 80:199 fault?
This code appears when the boiler detects that the water in the system is reaching the desired temperature too quickly, which usually happens if the radiators cannot dissipate heat fast enough. To protect the burner from wearing out due to constant starting and stopping, the system imposes a calculated waiting period. It is often caused by several radiators being turned off or the pump speed not being synchronised with the boiler's high power output.
This is more common in spring and autumn when the weather is mild and the house doesn't require the boiler's full heating capacity.
DIY fix possible
Wait for 15-20 minutes to see if the delay timer expires and the boiler restarts automatically.Perform a standard reset by pressing the 'Reset' button or turning the power off and on once.Check if the room thermostat or external controls are calling for heat.
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Gas Safe Register →Viessmann models that show the 80:2 to 80:199 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Viessmann 80:2 to 80:199 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026