Loxone Under Floor Heating Wiring

[Jack Davis]

Hi, 

Does anyone have any experience with the wiring of a Loxone Under Floor Heating System to work in conjunction with a standard HW system with Cylinder? 

The question at this stage is just around the wiring set up. Am I right in thinking that : 

1. The heating system should be wired as normal in a S Plan Formation with a wiring centre?

2. The Loxone Relay that controls boiler / pump for UFH will then also be connected into the wiring centre with usual wiring formation for S Plan  

The underfloor heating is controlled via the loxone mini server / Smart Switches / Actuators 

The Hot Water is controlled via a single channel programmer with cylinder 

How do we wire both the UFH and HW to turn on when required despite one being controlled by the programmer and the other via the loxone relay? 

Any information would be appreciated. The boiler will have x2 triggers so the HW and UFH can work separately. 

Kind regards, 

Jack 

[Simon Still]

There are loads of different levels of integration for Loxone with your heating.  At the simplest you could just have a timer block for heating and another for hot water outputting on two relays which replace to two relays you'd find in a dual channel CH clock.  

As you prefer you can then bring more control into Loxone - for example normally you have a hot water cylinder thermostat wired in-line with the hot water circuit.  With Loxone you could wire the stat back to Loxone so that you could monitor (and adjust) water temperature. 

[Jack Davis]

Thanks Simon. So I’m currently due to sit the training course in Feb so I’m not up to speed yet with the programming, but we are at a first stage with a property that incorporates Loxone UFH controls & possibly HW

Im familiar with S or Y plan wiring but the loxone takes a different wiring set up, is that correct - Coukd you offer any advice on how you wire a the heating in terms of cable & core(s) from relay(s) / Boiler / Cylinder / is there a requirement for 2 port valves? Or again is the Mini server doing the switching?

Thanks

Jack

[Simon Still]

On Wednesday, 10 January 2018 17:24:01 UTC, Jack Davis wrote:

Thanks Simon. So I’m currently due to sit the training course in Feb so I’m not up to speed yet with the programming, but we are at a first stage with a property that incorporates Loxone UFH controls & possibly HW

Im familiar with S or Y plan wiring but the loxone takes a different wiring set up, is that correct - Coukd you offer any advice on how you wire a the heating in terms of cable & core(s) from relay(s) / Boiler / Cylinder / is there a requirement for 2 port valves? Or again is the Mini server doing the switching?

Are you speccing the heating system from scratch in a new build house or is this a refurb with existing kit?  Loxone is a programmable logic controller and a load of relays - yours is a bit of an open ended question. 

It's worth asking whether Loxone is necessary or desirable for controlling your heating.  Modern boilers can be controlled in a much more sophisticated way than simply being on/off  - the power can be controlled for max efficiency.  Underfloor heating works best with a low (and variable) flow temperature.  While you could program all of these features into Loxone you're unlikely to improve on the manufacturer's own smart controls.  

Using the manufacturers control system I switch mine on in about October and Off in about March - between those times it doesn't need touching.  I've a storage combi boiler so there's always hot water at mains pressure. 

[Jack Davis]

Hi Simon, yes it’s new build, the developer has specified Lighting, heating & intercom to be Loxone controlled. It’s three stories, a manifold on each floor for UFH. What I’m trying to Establish is if we should wire the heating system as we normally would through a wiring centre, but replace the traditional CH programmer with a Loxone Relay. There’s not too much information out there about this but it just have been done before..

[Duncan]

replacing the normal timer switch/control with a single loxone relay will not utilize loxones heating capabilities fully but you may want 'wiring centre' - just a box where all the connections can be made.

an S plan type setup gives you more control - heating and hot water are under separate control, and usually with ufh, each manifold has a separate 2 port valve and control signal driven by loxone.

there are many ways of wiring it, but in essence, each zone would need a switched feed controlled by lozone to a valve actuator (driven by an intelligent room controller in loxone) and for each manifold the demand of all the valve actuators on that manifold are 'OR'd together to drive the 2port valve/manifold pump, so that any single heating zone demanding heat will open the manifold 2port valve and turn on the manifold pump to circulate the water.

you also need an 'OR'  of each manifold pump signals along with the hot water demand, and this feeds the boiler control, so any demand of any heating zone or the hot water will fire up the boilder.

since you can have combinations of 24v or 240v zone actuators and 240v zone valves/pumps, the wiring depends on the type of devices you are using, and the signals can be driven by loxone relay outputs (wired or air), dmx relays, knx actuators or even network relays - anything that loxone can turn on or off

unfortunately the loxone course wont teach you much about heating design/control, perhaps just how you might configure loxone parts. They wont tell you about other cheaper ways of doing it such as dmx relays.

the heating companies controls can add up to quite a lot of money, depending on how many zones you have in the house - my own build would have cost around £1800 for their own thermostats/controls, but the loxone install to control the heating cost less, leaving the lighting and all other loxone facilities almost free apart from switches and dimmers.

[Simon Still]

[the heating companies controls can add up to quite a lot of money, depending on how many zones you have in the house - my own build would have cost around £1800 for their own thermostats/controls, but the loxone install to control the heating cost less, leaving the lighting and all other loxone facilities almost free apart from switches and dimmers]
Indeed - and that was part of my initial calculation but in a modern, well insulated house there is an argument you don’t need that complexity (and its working in my house over 2 years now). Weather compensation controlling just two zones and no internal thermostats. No motorised valve controllers needed. Ended up being cheaper than integrating into Loxone and far simpler to install.

[Jack Davis]

Hi Duncan, thanks for your reply. The heating setup is still an open book so to speak. Could you recommend how you would install this system with regards to the system components and wiring for UFH & HW

At present I had planned on installing a CAT7 to each manifold location for the actuator(s) along with a 5 core 2.5mm to control the pump / 2 port valve.

There are x3 manifolds (1 per floor each with 5 Zones)

I had then planned to install a 5 core 2.5mm to the boiler which would then be controlled from a Loxone relay and programmed to heat / pump once a actuator called for heat. We have loxone intelligent switches installed in each (zoned) room using tree wiring.

If, for now you could explain how this should be wired correctly - I’ll follow your advice & learn the programming in February..

Any more info would be great, I’m a beginner in the deep end at the moment with regards to the heating set up..

Thanks

[Jack Davis]

Does anyone know of any wiring diagrams for this type of set up? Thanks

[Duncan]

your planned wiring will work well if you are using low voltage manifold actuators, but you cant use the cat7 for 240v actuators, unless you use the cat7 to control local 240v relays/ at the manifold to power 240v actuators. it is difficult to give exact wiring instructions unti you have chosen your components such as actuator voltage, and decided whether you want a centrally controlled setup or distribubed control at each manifold using a bus technology such as dmx, knx, tree or even simple local relays

do you have enough loxone digital outputs? you will need 20 or so for heating control.If you dont have enough then you might choose to use a bus controlled relay technology to expand the system such as loxones tree, dmx relays or knx actuators rather than buy more loxone extensions.

mostly the wiring is decided by the voltage rating of the acutators (240v or 24v) and whether you want all the switching to be central or distributed to each manifold.

for each manifold, you could get away with t+e - the live is switched by loxone and feeds power to the 2 port vavle - when this opens it then passes its own live 240v supply onto the pump.

you will also need a 240v t+e to the 2 port valve controlling the feed of hot water to your water storage tanks. this needs to go to a digital output sending 240v controlled by loxone.

the boiler, 2port valves and pumps use very low power, so you really dont need 2.5mm - 1 or 1.5mm 240v cable would be perfectly adequate.

if you want to use 240v actuator but controlled directly from loxone, a multi-core 240v rated control cable will work fine - 1 neutral shared and a live for each actuator, but you shouldnt power the pump down the same cable as they arent rated high enough. so in your case a t+e for the pump and a 6-core or higher cable for the actuators.

personally i wouldnt use loxone relays to switch things like the pumps - i would add a higher current rated external relay between, either at the loxone end or at the pump end, switching a local 240v supply, but the loxone relays should be fine for 240v actuators.

[Jack Davis]

At the moment we have specified 24v actuators Running X1 CAT7 to each manifold using 1-Wire method so the wiring would be ‘distributed control’ at each manifold location. We could specify enough digital outputs at this point so if we need 20 or more that is fesible.

I now understand the requirements for the pumps / 2 port valves from your description but how would I incorporate the boiler into this set up to turn on when the pump is activated?

Thanks

[John Verdicchio]

I've included how I've wired my home heating. It is a mix of radiators (central heating CH) and Under Floor Heating UFH. I've used UK colouring for the 240V and red/black for the 24V DC. The DMX switching seemed like a  very cheap way of controlling large numbers of things e.g. up to 256 things with one Loxone DMX unit(*) . One can also get 24V actuators that fit on thermostatic radiator valves. I use these  as well. Can use all the extra channels for lights.

(*) DMX runs up to 512 things per "Universe" , however, Loxone only support 128. They have two "Universe"s on their DMX extension.

[Duncan]

i agree completely with using dmx, but it depends whether an installer intends to use everything loxone (seems to be expected by loxone of their partners now a days), and also to a certain extent whether the dmx extension is a worthwhile investement compared to using up spare relay outputs if you have them.

i always add a cat5/6/7 cable to installs to various locations so that it can be used for dmx and/or knx as there are always unanticipated requirements post-install - even if you never use it, its so cheap and easy to install at build time.

dmx controlled din rail relays for heating/lighting control are available such as http://www.srslight.sk/en/lighting/product/101/dts16r-din?keyword=relay which offers 16 relays sufficient to control acutators, 2port valves and pumps. - these are available for around £150 each.

as far as i know, the dmx extension has 1 universe and can control 128 devices, but you can use more than 1 extension if rquired to control more devices.

[John Verdicchio]

Look very nice but pricy. I went for "High Power 24 Channel RGB 3A/CH DMX512 Controller Led Decoder Dimmer 500Hz Flicker Free Smoother Dimming DMX Signal Indicator Flashes Function DC 5V-24V" via Amazon for £40. Only issue with these is they are not DIN rail mountable. So, just hanging around my cabinet at the moment. Need a permanent fixing method. However, I'm not using an installer and just doing it all myself.

It looks like the DMX extension has two outputs on it - so two universes ? Duncan, you're probably right. Or is it just 64 per output? If I run out of DMX space on 128 units you'll be able to see my house from space!

[Duncan]

dmx is a version of rs485 - its a differential signal so +, - and ground to help reject interference

the ideal wiring is the + and - as a twisted pair plus the ground - quite a lot of dmx devices use cat5/6/7 cable and rj45 sockets, which is arranged to use the orange and orange/white cables as the twisted pair, and brown and brown/white as the ground, so fulfilling the best cable practice.

if you want to din mount things, there are green plastic din mount brackets and backs from aliexpress etc that you can glue/screw or zip-tie things onto such as:
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20180111053704&SearchText=din+rail+brackets

[Naran Khetani]

I now understand the requirements for the pumps / 2 port valves from your description but how would I incorporate the boiler into this set up to turn on when the pump is activated? 

Not sure if you got a response to the above, but i was scratching my head with all this before I did my project, and from what I have read you've got great advice. My setup was very similar to everything that's been mentioned so far. In regards to how you tell the boiler to fire, in my setup we let the microswitch on the 2-port valve trigger voltage which then tells the boiler to fire, the boiler will have a trigger voltage input, Unless you want to control the boiler directly in which case if you have a valiant you can use an eBus only read about this would love to get this but the interface module is too pricey.

http://koenserneels.blogspot.co.uk/2017/07/home-automation-heating-with-ebus-and.html

On Wednesday, 10 January 2018 23:47:02 UTC, Jack Davis wrote:

[Duncan]

pretty much all boilers have a volt free trigger input (a simple relay closing the 2 connections will fire the boiler) and some have a 240v input as well to fire it.

the 2 port valve contact could be used, but when you have 3 manifolds and a hot water demand, you need to use an OR block in loxone driven either by the manifold pump outputs, or all the zone valve outputs, plus the hot water demand - the output of this OR then directly triggers the boiler input if there is any heat demand from any device/room.

some people try to use electronic boiler controls but these are usually difficult, expensive and proprietry, and as most boilers are fully modulating anyway its easier to leave the boiler to do its own thing with a simple on/off input from loxone.

on a related note, weather compensation in the boiler doesnt really add much in most installs - the boiler may increase its output temperature during cold weather, but the manifold blending thermostat stops this affecting the water temperature in the ufh coils. in order to implement temperature compensation you need to give loxone control of the manifold temperatures by using a 0-10v thermostatic actuator on each manifold blender valve and a manifold temperature sensor - then loxone can increase the manifold temp during cold weather to increase the power output of the heating coils to compensate for slower heating in cold temperatures.

[Andrew B]

Interesting use of DMX!

FWIW, in case you didn't see my post about the switching away from the Loxone DMX controller... a couple of months ago I removed mine from my system and switched to using this:

http://dmxking.com/artnetsacn/edmx4-pro-din

(actually, I'm using this one for my use case:  http://dmxking.com/led-pixel-control/ledmx4-pro)

You need to write UDP packets to it, and they're complex enough that you would need to use picoC code (or run your logic on another device as I am)... but it handles multiple full Universes, has a substantially faster refresh rate, there is lower latency response to commands, and it has better startup behaviour.  Ethernet trumps the Loxone extension bus (which itself is a proprietary protocol on top of RS485, I believe).

I've been *much* happier with my lighting since switching.  

I plan to use its recording/playback feature to implement an "away mode", but haven't gotten around to that yet.

[John Verdicchio]

Duncan, I wonder if I've missed out on some fine control here . I have a binary on/off valve for the boiler to UFH ; control for the UFH pump and individual actuators for each circuit. The system came with an analogue thermocouple to sense the manifold temperature and there is also a valve that allows the pump to run pushing the hot water around the UFH pipes, but doesn't return the water back to the boiler. I guess this is to have the system use up the heat in the coils without running the boiler constantly. So much question is: does this actually matter? It doesn't seem to so what am I potentially loosing ? I have the closed-return valve wired but not used. I haven't wired up the thermocouple wires and then there is the issue of decoding the output of the thermocouple to something Loxone understands.

[Simon Still]

On Thursday, 11 January 2018 22:56:56 UTC, Duncan wrote:

the 2 port valve contact could be used, but when you have 3 manifolds and a hot water demand, you need to use an OR block in loxone driven either by the manifold pump outputs, or all the zone valve outputs, plus the hot water demand - the output of this OR then directly triggers the boiler input if there is any heat demand from any device/room.

My understanding is that the boiler 'call for heat' is conventionally run from the microswitch on the valves as a safety feature.  The microswitch is only activated when the valve is physically open so if it jams/when it fails you don't get have the boiler firing and the pump running into a closed circuit.  

on a related note, weather compensation in the boiler doesnt really add much in most installs - the boiler may increase its output temperature during cold weather, but the manifold blending thermostat stops this affecting the water temperature in the ufh coils. in order to implement temperature compensation you need to give loxone control of the manifold temperatures by using a 0-10v thermostatic actuator on each manifold blender valve and a manifold temperature sensor - then loxone can increase the manifold temp during cold weather to increase the power output of the heating coils to compensate for slower heating in cold temperatures.

 as you say, dependent on install - one of my two UFH circuits runs directly from the boiler output, the other is at a lower temperature so has a mixer valve.  Both controlled by the Weather Compensation controller.

"compensating for Slower heating" doesn't really describe what weather compensation does when configured correctly.  

A house will have a constant rate of heat loss at your target internal temperature and an outside temperature.  With a lower outside temperature (Delta T larger) heat loss increases so the UFH flow temperature is increased to match the higher losses using a curve (as the relationship isn't linear).   https://www.loxone.com/enen/kb/heating-curve/ will do it

When the curve is set to match the house performance you get very stable internal temperatures 

[Duncan]

generally speaking, the manifolds for ufh have a pump and a blender - the blender controls the flow of hot water into the manifold (which pushes cooler water out of the manifold exit valve back to the boiler) if its a 2 port valve, or a 3 port valve which mixes hot water from the boiler and cooler water from the manifold return - either of these valves is controlled by a thermocouple mechanically linked to the hot side of the manifold. the control on the blender valve usually looks like a radiator trv and allows you to set the manifold hot side temperature and it will be kept stable by the valve the thermocouple.

if you have an  electric thermocouple on the manifold and a wired return valve, it sounds like you have the components required for electronic adjustment of the manifold temperature, which would allow for temperature compensation - this fits one of 2 scenarios:

1) the idea is that either you have a house set at a constant temperature all the time, where the ufh power output balances the heating losses - when its cold the manifold temperature goes up and balances the increased heat losses by the colder temp outside.

this system has along term stable house temperature but doesnt allow different room temperatures easily, or more importantly different temps at different times of the day, and is very slow to respond if you want to boost a temperature

2) usually most ufh systems have a much higher heat output than required for constant temperature, giving them the capacity to heat up a room to a higher temperature (still slow compared to radiators though), the manifold tend to run quite a bit higher temps than room temperature to deliver this, and each zone is controlled with a local temperature sensor and actuator on the manifold to stop significant overheating - each room can have different temperatures and different times (i.e. using the loxone IRC) so for instance a bathroom might be hotter in the morning and evening than the day, and a living room at a fairly constant standby temperature in the  day but at 'comfort' or warmer in the evening. - temperature compensation at the manifold is less important in this case, but helps to keep the time to heat up constant when its colder outside, and reduce overshoot during warmer weather.

if you  have hot water storage, and assuming you are using IRC blocks and a temp sensor for each heating zone/room, you would set your boiler hot enough to reduce legionella in the tank (above 60 deg c) and the ufh manifold temperature warm enough heat the rooms depending on floor covering - so 45-60deg for carpets and 30-40 deg for hard floors.

temperature compensation at the boiler is not going to help you here as it wont change the manifold output temperatures due to their own thermostatic control, but manifold temperature compensation will help ensure that when its really cold outside, the manifold temperature rises to the higher temps and increases the heat output in each coil, allowing the room to heat up at a similar rate to when its warmer outside and to reach the target temperature, and when its warmer outside the manifold temperature is lower, reducing the tendency for the room temp to overshoot the set temperature.

the first option is more often seen in buidlings with hard floor coverings and open plan layouts, often with one temperature per floor, and is simpler to build/install and more stable, but doesnt give the occupier the same fine control over temperature/time as the 2nd option. the 2nd option feels more like our traditional radiator type installs but its a personal choice at the end of the day. building an install that can be configured either way is probably the right way to go if you have the choice, but will cost slightly more in terms of room sensors and actuator valves, but given that a 1-wire sensor is £1 and an actuator around £8 it seems worth while to me. Retrofitting with technologies like air would of course be much more expensive though.

[njamessimpson]

I am considering using the radiator valves for a simple on/off control of garden irrigation. What is the best way to open/close? I have IRC in normal rooms which controls valves via temp input. But just looking to fully open/close valves with some sort of scheduler.

Thanks

[RSin]

I'm appreciate some more eyes to look at what I'm doing with a new install. Put it in this thread to keep things together.

3 UFH manifolds all with pumps

4x 2-port zone valves for - 3xHeating, 1xDHW

DHW unvented cylinder

All in S-Plan.

Loxone room stats via 1-wire as well as cylinder temp (not high limit stat)

Bunch of DMX relays.

See attached pic of intended wiring and below my understanding of the S-Plan wiring/control method.

I like the idea of the 2-port valves triggering the boiler fire & pump so that it only does it when there is somewhere for the heat to go. Are there any disadvantages to this rather than a relay direct between loxone and the boiler?

NOTE: not sure about the connection to the cylinder stat whether that's 230v or extra-low. Anyone help with that? Its an ESI stat on an OSO cylinder.

DHW DEMAND

1.Loxone 1-wire temperature sensor on cylinder compares to target value and needs more heat.

2.Loxone closes DMX relay allowing 230v to pass to Cylinder stat box.

3.Stat box compares whether cylinder temperature below safe temp AND 230v coming from Loxone

4.If AND is met, 230v is passed to 2-port valve from the cylinder stat box and it opens.

5.Once it opens 2-port valve switch contacts allowing 230v into Grey and out of orange to the Switched live of the boiler – the boiler fires and starts its pump.

6.If the high-stat reads over 80-degC it cuts power to the 2-port valve and it closes to prevent cylinder overheat (G3 requirement)

HEATING DEMAND

1.Loxone 1-wire temperature sensor in room compares to target value and needs more heat.

2.In config the IRC feeds the ITC to output

3.Loxone closes DMX relay allowing 230v to pass to 2-port valve and it opens.

4.Once it opens 2-port valve switch contacts allowing 230v into Grey and out of orange to the Switched live of the boiler – the boiler fires and starts its pump.

5.Loxone closes DMX relay which opens room 230v actuator

6.After delay of 2 minutes Loxone closes DMX relay which starts manifold pump that room is connected to.

[Rob]

Your thoughts seem to make sense but I do wonder why you are using 1-wire for temperature and not using the touch switches instead?

We're in a similar situation and, although we're installing UFH on the ground floor, we are keeping the existing radiators on the first floor and the hot water cylinder. Although you could do lots of sophisticated monitoring/control, to start with I am keeping it simple and essentially replacing the usual heating/HW controller with Loxone relay outputs. These will just switch 230v into the 2-port valves (which in turn fires the pumps/boiler) depending on where the demand is triggered, based on the IRC/ITC logic. This avoids a whole lot of hassle rewiring the heating/HW system controls. I am reading temperature from the Loxone touch switches in each room and using air valve actuators on the radiators and tree actuators on the UFH manifold.

[RSin]

Anyone else? Can you get the 2-port valves to start the UFH pumps or is this a problem with it being too much of a load with the motor?

On Sunday, 22 July 2018 23:39:43 UTC+1, Rob wrote:

Your thoughts seem to make sense but I do wonder why you are using 1-wire for temperature and not using the touch switches instead?

Slightly off topic but as you've asked... :)

Touch is Tree, tree = bad (to me anyway!) there is no way I want to ever rewire the house I've just done. If everything Loxone goes T-up I have the wiring to swap to KNX or another system. Granted, 1-wire is daisy chained, but I have 8-cores plus a drain wire so many chances to rewire if one core somewhere breaks. The touch switch is £45. In most rooms I don't need all the functionality so can get a switch for £10 and if I replicate all the functionality it will cost £25. The 1-wire temp sensor is £0.30! Also if I want volume control, blinds and rooflights I've run out of corner switches. Don't get me wrong though, I like the way they look and if I went air/tree fully I'd probably have a different opinion.

[Rob]

Yes, the 2 port valves can switch power to the pumps. If you're using something like a Honeywell 4043H the contacts are rated at least 2amp so would be fine.