Installing hive on old system. No wiring centre?

[Mx19]

Hi all!

I’m about to install a hive stat on my old system.
It seems I don’t have a wiring centre anywhere and all the cables go to the old controller, can anyone confirm if this could be the case?

It also seems I’ve got no motorised valves anywhere, just a pump so obviously no idea if it’s an s or y plan system, or something different?

We will be getting boiler replaced down the line but not for a while as it still works etc I’d just like to learn more about the system!

I’m pretty happy just changing the cables in place but wanted to make sure that I can do that without a wiring centre?

I’ll attach another picture once if got the face plate of the controller off and if anyone is able to confirm it doing the right thing that would be great!

Thanks a lot.

 

[Swwils]

Why did you select the hive?

 

[oldbutnotdead]

Question- can you have the heating on without warming the hot water cylinder? If not then you almost certainly have a gravity system- I believe Hive can accommodate these but check first.

 

[Mx19]

It’s definitely a gravity system (I’m 99% sure) hive do accommodate these. Maybe I’m over thinking it all haha

 

[ericmark]

Gravity or thermo syphon systems often called C Plans come in three basic flavours, with no tank thermostat, with a tank thermostat so DHW can be left on in summer, and with tank thermostat and motorised valve so DHW can be a lower temperature to the central heating.

I have the system with no tank thermostat, which needs either volt free change over contacts in the controller, or a software fix and one set of contacts for the boiler and one for the pump, Hive has the latter.

However since your combining the thermostat and the programmer together it often involves some rewiring, this is likely the original system, the programmer is often a 10/16 option device, with both dip switches and physical links to change it from 10 to 16 options, with the C Plan we have the 10 option which stops you selecting CH only, you can only select DHW or DHW and CH.

But you have two devices your trying to combine into one, and the problem is working out how to remove the existing thermostat. Start from scratch is easy, one wire to boiler, and one wire to pump, where the problem lies is working out what you already have.

My programmer I found was not wired correctly to start with, should have been a triple and earth cable programmer to boiler, but it started red, yellow, blue, and arrived brown, black, grey and one core was not connected.

So I needed a way to independently control DHW and CH and power the unit with two wires, my method was Nest Gen 3, in hind sight maybe not the best idea, but it worked.

However step one was try to work out what I had, and the same goes for you, the picture will not open, looks like 4 cables, so would guess one feed, one to boiler, one to pump, and one to thermostat, so I would think Hive would be easy to fit.

 

[Mx19]

Gravity or thermo syphon systems often called C Plans come in three basic flavours, with no tank thermostat, with a tank thermostat so DHW can be left on in summer, and with tank thermostat and motorised valve so DHW can be a lower temperature to the central heating.

I have the system with no tank thermostat, which needs either volt free change over contacts in the controller, or a software fix and one set of contacts for the boiler and one for the pump, Hive has the latter.

However since your combining the thermostat and the programmer together it often involves some rewiring, this View attachment 280556is likely the original system, the programmer is often a 10/16 option device, with both dip switches and physical links to change it from 10 to 16 options, with the C Plan we have the 10 option which stops you selecting CH only, you can only select DHW or DHW and CH.

But you have two devices your trying to combine into one, and the problem is working out how to remove the existing thermostat. Start from scratch is easy, one wire to boiler, and one wire to pump, where the problem lies is working out what you already have.

My programmer View attachment 280558 I found was not wired correctly to start with, should have been a triple and earth cable programmer to boiler, but it started red, yellow, blue, and arrived brown, black, grey and one core was not connected.

So I needed a way to independently control DHW and CH and power the unit with two wires, my method was Nest Gen 3, in hind sight maybe not the best idea, but it worked.

However step one was try to work out what I had, and the same goes for you, the picture will not open, looks like 4 cables, so would guess one feed, one to boiler, one to pump, and one to thermostat, so I would think Hive would be easy to fit.

Thanks a lot For your reply! You’re exactly right in what the four cables are for, and we have a system without a tank thermostat.
I was assuming it’s just a case of taking the cables out as the old controller and putting in the same places in the hive controller, by same places, I mean obviously hot water on etc?

 

[Mx19]

Here’s some more pictures

 

[CBW]

Should be able to transfer the wiring the same, but omit the live links as these are built into the hive dual channel receiver. Remove the room thermostat as described in the first post and set the Hive to gravity.

 

[ericmark]

Should be easy enough to work out

I would guess as shown, you should be able to confirm, the cable to thermostat not longer required, of the three left all earths together, all neutrals together, boiler to 3 and pump to 4. Wiring job done, then program for gravity.

 

[Mx19]

That’s right!
It’s successfully installed! Thanks for everyone’s help!