Installing hive from h27xl

[Elnew]

Hi all,

trying to install a hive, my current system is combi with a hot water tank, drayton room stat and horstman h27xl programmable unit.

it was wired as below however i had removed the earth and neutral when i took the pic

https://ibb.co/qrvTdMd

The room stat is below

https://ibb.co/7N9F987

And original details on the h27

https://ibb.co/MC20wrM

All help very much appreciated

 

[stem]

The Horstmann connections are:

All of the existing wires to the Horstmann terminals relocate to the Hive receiver terminals (you will require the dual channel version) that have exactly the same function.

The exception is the live link wires shown dotted between L / 2 / 5. The Hive Dual Channel has these made for you internally already, so they can be discarded.

So:
N to N
L to L
Earth to Earth
The black wire in Horstmann terminal (1) called 'HW on' would go to the Hive terminal (3) 'Hot water on'
The brown wire in Horstmann terminal (4) called 'CH on' would go to the Hive terminal (4) 'Heating on'

Because the Hive carries out the functions of the room thermostat, the old wired thermostat needs to be decommissioned to prevent it overriding the Hive. It can't simply be disconnected as this would leave the heating wiring 'open circuit' and it will not operate. The thermostat can be decommissioned in several ways.

1. Find the origin of the thermostat cable. Note where the Brown and Black wires are connected and disconnect the entire cable. Then link the terminals where the Brown and Black wires have just been removed from together so that they are electrically connected. The old thermostat and its cable can now be removed.

2. Remove the existing thermostat and replace it with a junction box, connect the Brown and Black wires together and isolate the Grey neutral and earth

3. If you are happy to leave the current room thermostat in place and simply disable it, leave it where it is, and put the black wire in the L terminal along with the Brown wire that is already there.

You don't give much detail of the heating system the controls are connected to and it's a bit unusual (but not unknown) to have a combi boiler connected to a hot water tank (cylinder?) But if your system is fully pumped that is the default setting for the Hive, if it has pumped heating with gravity hot water circulation, then the Hive should be set to 'Gravity Mode'

 

[ianmcd]

if it has pumped heating with gravity hot water circulation

@stem you can not have gravity HW with a Combi, will have to be fully pumped

 

[stem]

I'm not convinced the OP has a Combi, frequently on here folks assume that white box in the corner is a 'combi' hence why I asked as a combi with a water cylinder would only make up a very small percentage of installations. however it is possible and If they do have a fully pumped system, then as I explained then nothing needs to be changed.

 

[Elnew]

hi, boiler i have is https://www.plumbnation.co.uk/site/...tPw4_ZfXlETF1rLlldj6WhtMcsL6_Da8aAgYfEALw_wcB

with a hot water storage tank

 

[stem]

Thanks for the clarification. It is a 'system boiler' as I suspected and not a 'combi boiler' as you originally said. Doesn't alter the wiring though you are just swapping the controls like for like.

 

[Elnew]

Thanks for the clarification. It is a 'system boiler' as I suspected and not a 'combi boiler' as you originally said. Doesn't alter the wiring though you are just swapping the controls like for like.

Thanks for the reply, so i had bought the single channel receiver, just ordered the double and will try wiring as above once it arrives with the current room thermostat set to 30 to be in constant over-ride if thats correct

 

[stem]

You aren't the first, or I'm sure the last, to buy the wrong version, although it usually seems to be people who do have combi's that buy the dual channel version.

You can leave the old thermostat on 30 degrees if you like and it will stop it overriding the the Hive, but to avoid the chance of it being disturbed and as it's so simple in your case to move the back wire to the L terminal, I can't imagine why you wouldn't. But it's your choice.