Hive & Baxi DuoTec 33 Combi Wiring Headache (Doesnt turn heating on)

[boothy01]

I'm having a nightmare trying to get the Hive unit I've got hold of working with the Baxi DuoTec 33 Combi Boiler I have at work.
The Hive I have got has both the heating and water control buttons (so I believe it's the 2 channel one), but I believe despite this Hive unit being designed for non-combi boilers, it does work with them. I say this because I've had a new boiler fitted at home (a Potterton Titanium 33 Combi) and that has the same 2 channel Hive fitted to it and works fine.

Given that the Baxi and Potterton boilers are both pretty much the same, I've tried wiring up the Hive to the Baxi in the same way it successfully work with the Potterton - no joy.

The boiler powers on (so Live/Neutral/Earth are all hooked up correctly), but can I hell get it to switch on the heating. The hot water still works when a tap is turned on (the boiler fires up as it should), but pushing the button on the Hive receiver doesn't make anything happen.

I've put some images of how I've currently got the wiring below so you can check its correct;



Just to give a bit more information;

There wasn't already a wired room stat in place - it was a wireless one which basically communicates with the boiler using a built-in wireless module. I've tried disconnecting that from the boiler PCB (just unplugs) since connecting up the Hive, but that still makes no difference.
When I first started looking at this, there was a link cable between points 1 to 2 (in the boiler terminal), so that's been removed as it said it needed to be.


I guess what I'm wondering is whether there's some form of link cable I need to use in the Hive wiring to perhaps connect a couple of points together, but if so, I'm unsure what and don't want to just start putting random cables in for fear of blowing stuff up!

Is anyone able to offer any help with this headache?

Thanks guys!
Steven

 

[stem]

I'm assuming that the black and grey wires were originally the switching wires. If so, you have connected them to heating 'on' and heating 'off' (2 & 4) so they will never be connected together. Hence no heating.

You really have the wrong Hive. The single channel that is designed for combi's and has a 'common' terminal and 'heating on' terminal which you would use for the two switching wires. There is no common terminal with the dual channel version, the live is switched directly to terminal 4 'heating on'

However, if you can tell us what terminals on the boiler the grey and black wires go to you still may be able to use it. You are fortunate that your combi doesn't use 24v for its control circuits as some do, otherwise, you would have just blown it up connecting it to 230v

 

[boothy01]

Hi Stem - thanks for your reply.
Looks like I'm lucky then not blowing it up!
I know it's technically not the right unit, but I already had it from a previous premises, so wanted to ideally use it rather than having to pay for a new unit...guess in hindsight it would have been very expensive if it meant a new boiler for the sakes of saving £180! Oooops.

Anyway, hopefully the answer to your question is;

Grey - Terminal 1 (Switched Live in)
Black - Terminal 2 (230V Live Out)

I did notice that there's no "Common" on this dual channel one, which as you say is clearly where my problem lies as you suggested.

Thanks for your help with this

 

[stem]

OK then, the boiler terminals should look similar to the attached diagram.

So, back at the Hive blackplate, remove and insulate the black wire, and put the grey wire in terminal 4 (heating on)

 

[stem]

First of all, I have only just spotted your photo of the boiler terminals, so sorry for asking you about them as well.

Looking more carefully at your photos, I actually I think it should have worked as you had it originally. The black wire from the boiler is only a permanent live and so would have just been connected to the Hives live internally anyway.

The idea is, that you need a switched live in on Boiler terminal 1 when heating is required. That would come from Hive terminal 4 (Heating on)which is taken from the Hive L terminal and internally switched to provide 230v at terminal 4.

If it still doesn't work, I suggest that you check the connection to the boiler 230v in is well made and that you haven't made the connection to the insulation instead of the conductor.

 

[AGAS]

it should have worked anyway

edit , sorry stem i only just seen your post

 

[boothy01]

Thanks stem.
I've checked all of the wiring again and everything's definitely connected conductor to conductor, but still doesn't work.
Just reading through what you've said above got me thinking; what if instead of connecting the Black cable to point 2 on the Hive, connect it to the L terminal on the Hive, leaving the Grey cable going to point 4 on the Hive.
The only reason I've suggested that is with you saying that point 2 would be only be a permanent live anyway, its just in case the Hive isn't doing its job for whatever reason?
Just wanted to check before I try it....just clutching at straws, as like you said, it should work as I've got it!

 

[stem]

The Hives central heating switch will be already connected to the Live terminal of the Hive internally, and the other side of the switch goes to Hive terminal 4, which will provide the switched live the boiler requires. (The black wire is only there to provide a Live for a programmer that isn't linked internally IE Hive single channel with the common terminal)

So what you need to do now, is check with a multimeter and see if you are getting a 230V live on the boiler terminal 1 when the heating should be on. If you are, the Hive is working.

Are we missing anything obvious? Is the boiler thermostat up? are you sure you have a dual channel version?

 

[boothy01]

Stem, I've got some good news - and an embarrassing confession - it's all working now!
Turns out it is a single channel Hive, rather than 2 channel. I had presumed it was 2 channel because the thermostat had the water button on it, but I noticed the boiler control didn't have that. So my bad for getting that wrong!
That said, once I wired it up correctly - image below - (which I did using a combination of your instructions and the Hive manual, so thanks!), it still didn't worked. Checked it with a voltmeter and it wasn't outputting the switch voltage. That got me thinking...


Remember me mentioning that the boiler had a built-in wireless receiver fitted which communicated with a wireless room stat/timer? Well everything else I read online said that once the Hive was fitted, that wouldn't be needed any more so take the batteries out of the room stat and can even disconnect the wireless receiver from the boiler (all of which I did). It appears the Hive needs the Baxi receiver and wireless room stat to be fitted and functional in order for the Hive to work. Crazy I know, but it's true!
I basically had to set the Baxi room stat to "HI" and turn the HI temperature as high as it would go (30 deg) so it's basically on permanently. That doesn't actually fire the boiler up and start heating, but instead makes it so that when the heating button is pushed on the Hive the heating fires up as it should. Turn that Baxi room stat off again and the Hive ceases to function again.

So with that Baxi room stat turned up full and on 24/7, the Hive works exactly as it should for turning the heating on and off and can also do it through the App - everything works.

So after a few days of head scratching, we're there! Working Hive

Thanks very much for your help, and if nothing else, I hope this threat helps other people who are having Hive wiring issues too, as turns out it's not necessarily the wiring, but actually down to the old thermostat if it comes integrated into the Boiler from factory. Doh!

 

[Duzzer]

You should be able to disconnect and bypass the wireless stat that came with the boiler PM me if you need I'm a hive expert.

 

[AGAS]

duzzer why PM , share and share alike

 

[stem]

Well done! You got there in the end. Terminal 4 on the single channel Hive is 'unused' so would never have achieved anything.

If you aren't able to bypass it, then as you have figured, you will have to leave the Boilers internal controls permanently on 24 /7 and max temp.

I would suggest that now it's working that you tidy up the connections a bit, so you don't have problems in the future, all of the wire strands should be securely under the terminal without any whiskers poking out and the insulation should be closer to the terminals. Here's an example.

 

[boothy01]

Yes, shall tidy up on Monday when I'm next back in work - just wanted to get it up and running today as the previous timer was only a 24hr one so would have the heating coming on during a Sunday when we're closed, which was a waste of money/energy, so Hive will stop that and to also allow me to control the heating so I can make sure it's on early morning if I go in early to get a head start on things!

It's am however intrigued as to what duzzer has to say about removing the wireless receiver and cutting that out altogether, so fingers crossed he'll share that with us all

Thanks again for the help Stem - really appreciate it!

 

[Duzzer]

You slate BG engineers on here so being discreet

 

[AGAS]

Buzzer come on don't be shy , will help others out as well