Hive install... Yet again

[ph123uk]

Hi all,

Posted earlier in the week about fitting a hive dual channel to my combo boiler and was told it would be fine as detailed here:

https://www.diynot.com/diy/threads/...-and-they-wont-cancel-it.513499/#post-4266847

I don't mean to be "that guy" but I'm concerned that the dual channel version fires 240v from terminal 4 to the timer volt free switches.

Attached is a screenshot of the boiler install page saying not to connect anything to the "volt free" terminals.

Last thing I want is to pop my boiler this time of year, any advice welcome

Boiler is a vokera unica 28 he.

Am I just being too namby pamby?

 

[stem]

I can't see where it says:

not to connect anything to the "volt free" terminals.

If you are meaning the 'low voltage terminal strip' that is a different terminal strip altogether provided solely for Vokera controls and is labelled M4 and not M5.

But I can see that the instructions you posted specifically say that the boiler is designed to work with voltage free controls. More specifically "Single Channel" [Just like the Hive version you should really have]

However, you are wise to check before proceeding. The diagrams don't actually show where the two switching wires on the left of the diagram below go, so they could be connected to 24v or 230V at the other end depending upon your boilers internal circuity, unfortunately I don't know what that is. [In your previous post jackthom and ianmcd say it's OK to use the Dual Channel version] If you want further confirmation, you could call the manufacturer and ask them what the voltage is.

In addition, the diagrams in the manual do show it wired to voltage free contacts. (ie. the switching contacts are isolated from the 230V shown on the right) The Dual Channel Hive does not have voltage free contacts because they are connected to 230V internally.

In your previous post someone suggested that you check to see if the switching voltage is 230V. If it's not, as you have figured, putting 230V onto a 24v circuit won't end well. Having said that, the instructions do say that the thermostat wires to to the "high-voltage terminal strip" suggesting that they may possibly be 230V.

I have only fitted Hive to this type of boiler once, and I used the single channel version wired as the diagram above. As the contacts are voltage free they don't care if it's 24v or 230V passing through them.

 

[ph123uk]

Hi Stem,

Many thanks for the reply, it is massively appreciated.

I neglected to mention in this thread but I have the dual channel version due to my own stupid fault, Currys refused to cancel the order (tried to cancel 5 mins after order, before it was processed or even dispatched) SO as opposed to messing around, waiting 14 days for a refund (after they receive the item back) I thought I could spare myself some pain and somehow get this working - so this is entirely a "tail between the legs and beg" moment given its all my fault.

After reading the above, I believe I now have my head around this:

Seems from the boiler manual, that the switch does indeed go to a high volt "connector" (I hope i'm reading it right) (Says CN1 is the "Connection to PCB high voltage"

Might be some good news here?

 

[stem]

Looks possible. As the 230V from the mains supply goes there, it would be highly unusual for 24v to go to the same connector. If you know how to use a multimeter you could measure the voltage of the two thermostat switching wires (red and black) then you would know for certain. You can get one from most DIY stores or Screwfix etc for about £10. Then, at the same time that will allow you to identify which wire is the 'live' wire and which is the 'switched live' wire that would connect to Hive (4) 'Heating on'.

 

[ph123uk]

All done,

Popped the multimeter on it, found the switched live (230v which was nice) removed the mechanical clock wire, put the "spare" wire from the 4 core cable, to outlet 4 on the hive. The rest self explanatory obviously.

Took around 20 minutes all in. Thanks very much guys.