Low
S.74 on Viessmann Vitodens 200-W B2HF System

Your boiler is temporarily prioritizing the heating of your hot water over your radiators, meaning your central heating will be paused until the water tank is warm.

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.

What the manual says

Manufacturer manual

Heating suppression; heating DHW circulation pump active

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 200 W B2kf Combi installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Wait approximately 20-30 minutes for the hot water priority cycle to completeCheck your hot water temperature settings are not set excessively highEnsure your hot water timer is correctly programmed

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Related fault codes

S.75View →S.76View →

All 141 fault codes on the Vitodens 200-W B2HF System

Seeing a different code? Every code this model can display, in one place.

377A.11A.12A.18A.20A.21F.5F.7F.8F.9F.10F.11F.12F.13F.14F.15F.16F.29F.30F.49F.50F.57F.58F.59F.62F.63F.67F.68F.69F.70F.71F.72F.73F.74F.77F.89F.91F.92F.94F.100F.104F.142F.160F.161F.163F.182F.183F.184F.185F.299F.342F.345F.346F.348F.349F.350F.351F.352F.353F.354F.355F.357F.359F.361F.365F.366F.367F.369F.370F.372F.373F.377F.378F.379F.380F.381F.382F.383F.384F.385F.386F.387F.388F.395F.396F.399F.400F.401F.402F.403F.404F.405F.406F.408F.410F.416F.417F.418F.425F.430F.446F.447F.448F.449F.450F.451F.452F.453F.454F.455F.456F.457F.458F.462F.463F.464F.467F.468F.471F.473F.474F.517F.527F.528F.530F.540F.544F.545F.546F.547F.548F.549I.56I.57I.59P.1P.4P.8S.60S.75

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