# TRVZB VALVE CLOSE % IN OFF (Frost Protection)

**URL:** <https://forum.ewelink.cc/t/trvzb-valve-close-in-off-frost-protection/206367>\
**Category:** Free discussion\
**Created:** [November 2, 2025, 1:11pm UTC](https://forum.ewelink.cc/t/trvzb-valve-close-in-off-frost-protection/206367 "2025-11-02T13:11:45Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Alan-Racheter-DipEng](https://avatars.discourse-cdn.com/v4/letter/a/bcef8e/32.png) [@Alan-Racheter-DipEng](https://forum.ewelink.cc/u/Alan-Racheter-DipEng)\
**Post date:** [November 2, 2025, 1:11pm UTC](https://forum.ewelink.cc/t/trvzb-valve-close-in-off-frost-protection/206367/1 "2025-11-02T13:11:45Z")

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Please note that regardless of TRVZB Close % setting if the valve is in 'OFF (Frost-protection) Thermostat mode it will close fully to 100% if the ambient temperature is above the target temperature (Valve ‘Keeping’).  
Why would this cause problems ? Only relevant to situations that use a valve or valves that are set slightly open while ‘Keeping’ to allow a circulation path between flow and return in case the boiler’s frost protection thermostat causes it to fire up.