# ATAG ONE plus BCU module

**URL:** <https://community.homey.app/t/atag-one-plus-bcu-module/106440>\
**Category:** Questions & Help\
**Created:** [March 16, 2024, 8:30pm UTC](https://community.homey.app/t/atag-one-plus-bcu-module/106440 "2024-03-16T20:30:05Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Kasia\_Dziekciowska](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/kasia_dziekciowska/32/79206_2.png) [@Kasia\_Dziekciowska](https://community.homey.app/u/Kasia_Dziekciowska)\
**Post date:** [March 16, 2024, 8:30pm UTC](https://community.homey.app/t/atag-one-plus-bcu-module/106440/1 "2024-03-16T20:30:05Z")

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I have an Atag QR serie boiler, I have two heating zones in the house (top/bottom) and two ATAG ONE thermostats, or I need two BCU modules for this or is one enough? in the module manual, in position C there is a connection for 1 thermostat, what are the D,E,F connections for? If I connect two thermostats for C, D and E, F to terminal 19, 20, 21, 22 in the boiler, will I control two circuits with one BCU? , or I must have two BCUs (one for each circuit)?

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**Author:** ![OH2TH](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/oh2th/32/111414_2.png) [@OH2TH](https://community.homey.app/u/OH2TH)\
**Post date:** [March 17, 2024, 6:35am UTC](https://community.homey.app/t/atag-one-plus-bcu-module/106440/2 "2024-03-17T06:35:14Z")

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