Low
S.96 on Vaillant ecoTEC exclusive 627 VU 256/5-7

Your boiler is performing a self-diagnostic check on its internal temperature sensors and has temporarily paused heating until it confirms everything is working correctly.

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

Return temperature sensor self-test / Return sensor test running, heating demands are blocked.

From this model's manual
Verified against the Vaillant/Vaillant Vaillantpro 0020193966 04 Ecotec Exclusive System Installation I 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 up to 15 minutes for the automated test to completeSwitch the boiler off and back on at the fused spur switch to trigger a restartEnsure all radiator valves are open to allow for proper water circulation

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Related fault codes

S.97View →S.98View →F.23View →

All 72 fault codes on the ecoTEC exclusive 627 VU 256/5-7

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

F.00F.01F.02F.03F.10F.11F.12F.13F.20F.22F.23F.24F.25F.26F.27F.28F.29F.32F.33F.35F.42F.49F.55F.56F.57F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.80F.81F.82F.83F.84F.85F.90F.94S.34S.36S.37S.39S.40S.41S.42S.46S.53S.54S.55S.56S.57S.58S.59S.76S.86S.88S.92S.93S.97S.98S.99

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