Honeywell ST9400S1001 to Hive SLRC1

17 Dec 2022
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United Kingdom
The boiler is a WB GreenStar 38CDi Classic.

We bought the Hive Thermostat Receiver and Hub for Combi boiler.

The Honeywell had cabling to its Earth, Live, Neutral 3 and 4 terminals (terminals 1 and 2 not connect/wired).
The Hive Receiver was wired the same.

All paired and Hub set up.


Hot Water is ON .. Good
Heating though is off ... Wont come on even when I set it to Boot on Heating. I see why people say it will save on bills ... the thing wont switch my heating on!

Also the Hive App and thermostat only register/show the heating settings, nothing for hot water.
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Did you make any changes to the room thermostat as that may help diagnosing your problem.

Looking a bit further I suspect you have fallen into the trap of swapping a programmer supporting HW & CH (ST9400) to a Hive Combi. The wiring requirements are different, the ST9400 had L & N (for power) and #3 for HW & #4 for CH. Given you have a Combi the connection on #3 probably did nothing.

If you look at the Hive Combi wiring needs, in addition to the L & N connections. You need to add a link wire on the back plate between L & 1, safely terminate whatever was in #3 in a terminal block or wago, then move what was previously in #4 across to #3.

The app won't show anything for HW as that's not controlled by Hive on a combi.
Last edited:

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