Upgrade Centaur C11 to Smart Controls

[SmashingPilot]

Hi,



I'm researching on upgrading my Centaur C11 controller to Hive. All the information online is a bit overwhelming and I want to make sure I purchase the correct product.

My current setup is a gas boiler with Centaur C11 controller. I believe it's a gravity system....cold water tank in the attic and hot water cylinder in the hot press?

There is only one zone, that is, the Centaur C11 just turns the heating on and that heats hot water at the same time. We have no thermostat.



I get adequate hot water heated through my solar eddi. So happy to keep the existing heating setup but add some smart controls.



Do I simply buy the Hive pack for a conventional boiler and leave the hot water connections blank, only connecting the the radiator connections?



I'm also not necessarily tied to Hive but looking for the simplest smart setup that will allow me to control via an app.

 

[stem]

My current setup is a gas boiler with Centaur C11 controller. I believe it's a gravity system....cold water tank in the attic and hot water cylinder in the hot press?

Don't confuse 'gravity fed' (cold water tank in the attic) with 'gravity circulation' (natural circulation of hot water that isn't assisted by a pump) They are completely different things. When it comes to controls, a cold water tank in the attic doesn't matter one way or another.

The C11 is a single channel timeswitch so as you describe both heating and hot water will come on together. However, some extra information is required about the type of system it is controlling. If the hot water cylinder is heated by gravity circulation (i.e. warm water rises, cooler water falls) and only the central heating is pumped, the answer will be different from a situation where both the hot water and the central heating are pumped.

If you do have gravity circulation of hot water, combined with pumped central heating a Hive Dual Channel would be a good choice as it has a 'gravity' setting specifically for this type of system. However if both hot water and central heating are pumped it's another story.

 

[SmashingPilot]

Thanks stem. So how do I find out the answer to your question in terms of what system I have?
I thought this would just be a straightforward job on replacing my single channel timeswitch with the single channel hive?
Here's the photo of the current timeswitch.

 

[CountryFan]

Post some photos of your cylinder and controls around it

 

[SmashingPilot]

Are these adequate enough?

 

[stem]

I thought this would just be a straightforward job on replacing my single channel timeswitch with the single channel hive?

From a wiring point of view that's correct. However, they are different devices with different functions:-

The timeswitch is just that, 'on' or 'off' related to time only.

Hive though, as well as providing time control, also includes a room thermostat function, so with the Hive fitted, when the room is warm, it will turn off the heating and the hot water as well. Although if you use the immersion heater (solar eddi?) for hot water, that may not be an issue for you. But just to swap the timeswitch for a Single Channel Hive controlling heating and hot water is a bit of a bodge up really.

Are these adequate enough?

Looking at the pictures, the pipes connected to the cylinder flow and return do appear to be 22 or 28mm which does suggest gravity circulation of hot water, but as the pump is not visible in any of the photos hard to say for certain.

If it does have gravity circulation of the hot water, then a Dual Channel Hive is required to do it properly, but it will need rewiring so that the Hot Water channel of the Hive controls the boiler and the Heating Channel controls the central heating pump. The Hive Dual Channel has a 'Gravity' setting especially for such installations.

 

[SmashingPilot]

Thanks for this stem. I'll have a closer look to see if I can find the central heating pump. Is this usually in the cupboard with the hot water cylinder?
In theory, if I can figure out how my system works, it could be possible to separate the hot water control and central heating with rewiring as opposed to pipework? Sorry, I know I'm jumping around a bit but its all new to me.

EDIT: I'm also not sure if this helps as well but the boiler I have is a logic system s24ie.

 

[stem]

I'm also not sure if this helps as well but the boiler I have is a logic system s24ie.

In that case, I believe that the pump will be an integral part of the boiler. If so, the hot water and the central heating will both be pumped (no gravity circulation) and I believe that you therefore have two choices:

1. Fit a Hive Single Channel in place of the Centaur C11as you originally suggested and suffer the limitations I mentioned earlier.

2. Add a motorised valve/s to allow independent control of the hot water and central heating and convert it to a Y-Plan or S-Plan. Then and a Dual Channel Hive will allow totally independent control of the heating and hot water.

Based on what you have said so far, I believe that the hot water would appear to be being heated by the boiler whenever the Centaur C11 is on, as well as the immersion heater!

 

[SmashingPilot]

In that case, I believe that the pump will be an integral part of the boiler. If so, the hot water and the central heating will both be pumped (no gravity circulation) and I believe that you therefore have two choices:

1. Fit a Hive Single Channel in place of the Centaur C11as you originally suggested and suffer the limitations I mentioned earlier.

2. Add a motorised valve/s to allow independent control of the hot water and central heating and convert it to a Y-Plan or S-Plan. Then and a Dual Channel Hive will allow totally independent control of the heating and hot water.

Based on what you have said so far, I believe that the hot water would appear to be being heated by the boiler whenever the Centaur C11 is on, as well as the immersion heater!

Just to your final question first. Yes, the hot water is also heated by the boiler whenever the Centaur C11 is on. Outside of that, water is heated by the solar eddi either by excess solar or if I use the boost function.

I think, for the moment, I am fine with the limitations going with option 1. Even in December and January, we've been getting enough excess solar to have the tank at maximum temperature. In a few years, we plan to do a bigger job on the house that will involve pipework for the heating, so I could move to option 2 then.

Appreciate your help on this. I've learned a lot.

 

[SmashingPilot]

Just thought I'd post an update. Purchased the 1 channel Drayton Wiser controller and thermostat. Just had to swap over two wires and connect to the existing backplate, took me 10 minutes.
Does the job perfectly and is just what I needed. Happy to now have some smart controls for the heating.