Low
S.74 on Viessmann Vitodens 200-W B2KF Combi

Your boiler is currently focused on heating your hot water, so it has temporarily paused the central heating for your radiators.

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

Check if a hot water tap has been left running slightlyWait up to 20 minutes for the hot water tank or heat exchanger to reach temperatureCheck your hot water timings on the control panel

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

Monthly cover means no unexpected bills when your boiler breaks down.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

Affiliate links. We may earn a commission at no extra cost to you.

Related fault codes

S.73View →S.14View →

All 140 fault codes on the Vitodens 200-W B2KF Combi

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

A.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

Related guides you might find useful

Radiator not heating up

One cold radiator is usually a stuck valve pin or trapped air.

Read →

Hot water works but heating does not

On a combi it is usually the diverter valve. On a system boiler, the motorised valve.

Read →

No hot water but heating works

Almost always a stuck diverter valve on a combi.

Read →