Honeywell t40 to hive

[includin2]

First post. I'm hoping to switch from my old Honeywell t40 to a single channel hive for my combi boiler, Worcester green Star 24i.
I've read many threads but I just wanted to double-check that it's a straight swap and I don't need a linking cable.
The cables go earth, black, light grey and brown.
Yellow and Green -> Hive earth

Black (Honeywell position 2) -> Hive N

Brown (Honeywell position 1) -> Hive L

Grey (Honeywell position 3) -> Hive ?3

also connect Hive 1 and L?

 

[ianmcd]

Nope the Hive needs a permanent live you dont have one, at your thermostat, do you also have a timer/programmer ?

 

[includin2]

Just the timer on the boiler.

 

[Mister Banks]

Nope the Hive needs a permanent live you dont have one, at your thermostat, do you also have a timer/programmer ?

Not for me to contradict but isnt the brown on terminal 1 on the old stat a permanent live?

If so then the OP can connect on Hive.......

Brown to L
Black to N
Grey to 3
and loop L to 1

 

[ian1182]

The Hive receiver would normally replace the existing timer/programmer rather than the thermostat. As ianmcd says it requires a permanent live connection. In theory when an on period is selected on your timer there may be power at the thermostat on terminal-1 but that depends on your Combi having voltage free switching or not. If it's the former there will never be 240V presented to the thermostat. Before you start it's best to determine which mode your combi has been wired. If you have a multi meter it can be checked, with great care of course, by verifying if there is 240V on terminal 1 when the timer is on. You would then have a "permanent" 240V supply when (and only when) the timer is on. It's a real bodge and far from ideal. Not something I would be happy with.

 

[CBW]

The Hive receiver would normally replace the existing timer/programmer rather than the thermostat. As ianmcd says it requires a permanent live connection. In theory when an on period is selected on your timer there may be power at the thermostat on terminal-1 but that depends on your Combi having voltage free switching or not. If it's the former there will never be 240V presented to the thermostat. Before you start it's best to determine which mode your combi has been wired. If you have a multi meter it can be checked, with great care of course, by verifying if there is 240V on terminal 1 when the timer is on. You would then have a "permanent" 240V supply when (and only when) the timer is on. It's a real bodge and far from ideal. Not something I would be happy with.

Just review

Hive receiver keeps going offline, no lights

Hi, I’ve had hive installed by British Gas about 4 years ago, trouble free. I started up my central heating in October, and found it was offline, never happened before. As there were no lights at all on receiver, I phoned Hive, and they got me back up and running. Since then it has...

www.diynot.com

This makes me suspect it's a case of the Hive receiver being wired behind the timer. The timer is going on & off which is why the Hive has no lights.

Greenstar 24i is 230vac mains voltage.

 

[ianmcd]

if you want to use the wiring at the existing thermostat you will have to set the timer on the boiler to constantly on

 

[ianmcd]

Not for me to contradict but isnt the brown on terminal 1 on the old stat a permanent live?

no it is not a permanent live, it is only live when the timer is calling for heat, can be used with the timer set to constantly on , but not ideal, if someone turns the timer off or it fails the hive wont have power