BartW Posted January 5, 2023 Share Posted January 5, 2023 Hi, This may have to go into another part of the forum, although it is totally UFH related. Basically, three bathrooms in the house will have electric UFH. Now: - each UFH matt will have a floor probe for temperature. Assume 10k Ohm @ 25C temp. - I am trying to avoid having a multitude of different controls, thus - I am installing Loxone Miniserver, and no separate room stat for the bathrooms Is my thought process correct and will I get the below to work? - temp probe to be connected to Digital Input (range 6V to 24V). - Loxone picks up voltage signal affected by resistance that modulates upon temperature (example curve here: https://www.northstarsensors.com/calculating-temperature-from-resistance ) - programming sequence turns Loxone relay output on / off. This could be something like "IF volts reading across the input >= 12V, switch relay ON". Question: - how do I establish voltage drop across the resistor? And how would I translate it into the programming? I am dark in the woods... Thanks! Bart Link to comment Share on other sites More sharing options...
Dan F Posted January 5, 2023 Share Posted January 5, 2023 11 minutes ago, BartW said: - each UFH matt will have a floor probe for temperature. Assume 10k Ohm @ 25C temp. If you are using Loxone, why not use the 1-wire sensors? Then it's just a case of using a simple controler with configured hysteresis to turn UFH on/off. This is better than simple on/off. If you don't want to use 1-wire sensor than something with a linear 1-10v output would be easy to integrate via an analog input. You then simply map this to the temperature range e.g. 1v=0C, 10v=100C and within loxone you work with the temperature. Digital inputs a 0/1 so aren't suitable for temperature sensor, you'd need an external thermostat with a digital output. Link to comment Share on other sites More sharing options...
BartW Posted January 5, 2023 Author Share Posted January 5, 2023 Thanks, So I was initially thinking 1-10V input, but I don't seem to be finding any. Equally, Loxone tree temp/humidity/CO2 sensor could surely pick up the data I am after, and allow me to configure the algorithm? Then just a simple on / off on relay side? Link to comment Share on other sites More sharing options...
Dan F Posted January 5, 2023 Share Posted January 5, 2023 6 minutes ago, BartW said: Equally, Loxone tree temp/humidity/CO2 sensor could surely pick up the data I am after, and allow me to configure the algorithm? Well if you are controlling UFH, you need temperature sensor in the floor, not a wall sensor, so I wouldn't rely on the touch switch sensors. Relay is simply on off yes. Just need to controller with temp input, target temp and hysteresis (there are muliptle ways of doing this in Loxone) and then output is digital 0 or 1 to relay. Link to comment Share on other sites More sharing options...
BartW Posted January 5, 2023 Author Share Posted January 5, 2023 Just now, Dan F said: Well if you are controlling UFH, you need temperature sensor in the floor, not a wall sensor, so I wouldn't rely on the touch switch sensors. Relay is simply on off yes. Just need to controller with temp input, target temp and hysteresis (there are muliptle ways of doing this in Loxone) and then output is digital 0 or 1 to relay. Ok, great I will do some digging, but sounds I might be somewhat set for the first fix wiring at least in these areas. Link to comment Share on other sites More sharing options...
Dan F Posted January 5, 2023 Share Posted January 5, 2023 16 minutes ago, BartW said: Ok, great I will do some digging, but sounds I might be somewhat set for the first fix wiring at least in these areas. Daisy-chain shielded CAT6/CAT7 between all locations you need 1-wire temperature sensors and make sure you put these sensors in slab, screed or under tiles as required. https://www.loxone.com/enen/kb/wiring-1-wire-devices/ 1 Link to comment Share on other sites More sharing options...
Temp Posted January 5, 2023 Share Posted January 5, 2023 (edited) I've just had a 10k NTC fail so make sure your sensors whatever they are can be replaced or install spares. Edited January 5, 2023 by Temp Link to comment Share on other sites More sharing options...
BartW Posted January 5, 2023 Author Share Posted January 5, 2023 6 hours ago, Temp said: I've just had a 10k NTC fail so make sure your sensors whatever they are can be replaced or install spares. Yes, idea waa to bury two per bathroom with one being spare “for later”. Link to comment Share on other sites More sharing options...
Dan F Posted January 5, 2023 Share Posted January 5, 2023 I used these and currently have around 20 on single 1-wire extension. https://shop.loxone.com/enuk/1-wire-temperature-probe.html Link to comment Share on other sites More sharing options...
SteamyTea Posted January 5, 2023 Share Posted January 5, 2023 1 minute ago, Dan F said: I used these 14 quid each. Can I sell you some. Link to comment Share on other sites More sharing options...
Dan F Posted January 5, 2023 Share Posted January 5, 2023 (edited) 20 minutes ago, SteamyTea said: 14 quid each. Can I sell you some. I paid 8-10 for these I thnk. You are right though, Loxone prices aren't cheap and you can get these cheaper elsewhere. One of the reasons I paid extra from the Loxone was simply because they had 2.5m cable on them, which is long enough to put a sensor in the slab in a largish room and then hide connections in studwork, others I saw at the time were less than 1m. Looking today though, there seems to be a cheap supplier on amazon with good reviews and 3m leads: https://www.amazon.co.uk/AZDelivery-Stainless-Temperature-Waterproof-Raspberry/dp/B07KNQVWV2/?th=1 Edited January 5, 2023 by Dan F Link to comment Share on other sites More sharing options...
Alan Ambrose Posted January 5, 2023 Share Posted January 5, 2023 >>> I've just had a 10k NTC fail so make sure your sensors whatever they are can be replaced or install spares. Yeah, that's not the only mode of failure. I have one floor where the heating element has gone kaput a few weeks ago. I will investigate further but it almost certainly means taking up a resin floor, the UFH and the insulation underneath and relaying the lot from scratch. About the only difference between this and the two other electric UFH floors in this place is that a couple of years ago this floor overheated (not too badly but the floor was noticeably hot) when something in the utility cupboard pressed against the thermostat buttons. The floor had two spare thermistors laid under it for backup, but the existing thermistor was fine - it was the heating loop that is open-circuit. So, I would bear in mind possible failure of the heating wire. If and when I replace this lot, I have made a mental note to do the following: + try and ensure the controller is hardware fail safe. + prefer proportional over bang-bang control to reduce electrical stress. + check the provenance of the heating wire more thoroughly - it could be (duh) that not all heating wire is equal. + maybe lay two separate heating wires as well as multiple thermistors so there are ample backup circuits. I would be very cautious about having the control loop via automation software rather than a close loop in a dedicated thermostat / hardware controller. If I did choose to go down the automation route I would want some kind of local temperature trip as a backup. Link to comment Share on other sites More sharing options...
Kelvin Posted January 5, 2023 Share Posted January 5, 2023 Failure of electric UFH seems inevitable at some point consequently I ruled it out of our build. Link to comment Share on other sites More sharing options...
Alan Ambrose Posted January 5, 2023 Share Posted January 5, 2023 (edited) >>> Failure of electric UFH seems inevitable at some point To be fair, these 3 floors have been running for 7 years without a problem (well, up to this point) and I think the fast warmup of electric is more useful than water-based. Also, if your water-based UFH has a leak (my neighbour's did) then you have an equally tricky problem to solve. I personally wouldn't rule it out again. But If I did this again, I would be more careful (as above) and I would also pay more attention to the thickness of the insulation underneath, . Edited January 5, 2023 by Alan Ambrose Link to comment Share on other sites More sharing options...
Alan Ambrose Posted January 5, 2023 Share Posted January 5, 2023 I think with either electric or water-based UFH - in the future, I will interleave at least two cables / pipes in any floor so that if there's a cable fail / leak you can always easily just fallback to one loop. Link to comment Share on other sites More sharing options...
Kelvin Posted January 5, 2023 Share Posted January 5, 2023 My expectations are clearly different from yours as I wouldn’t consider a failure within 7 years to be fair. It’s a big upheaval to fix it. Link to comment Share on other sites More sharing options...
Alan Ambrose Posted January 5, 2023 Share Posted January 5, 2023 >>> I wouldn’t consider a failure within 7 years to be fair. Well I wasn't best pleased and my neighbour's water-based UFH lasted 30-odd years - but he has it below a fancy wooden floor, which is so much bother and expense he hasn't actually had it fixed yet. Just a factor of burying stuff in the walls and floors I guess. I don't think there's much wrong with the physics - in general the wattage and temperatures are both quite low. But a little more thought in installation and a quality check on materials would have been helpful. Link to comment Share on other sites More sharing options...
Thorfun Posted June 21, 2023 Share Posted June 21, 2023 resurrecting this thread as i'm currently looking at this. our tiler is installing the electric ufh mats in our FF bathrooms. i'm installing a Loxone system and have run cat6a to our AC units and GF UFH temp sensors for 1-wire control so could easily extend that loop to include the electric ufh temp probes on the first floor. my question is would the power for the electric ufh have to run all the way back to the loxone cabinet? with a standalone thermostat/controller we could run it as a spur of the ring main. or is it possible to put some form of independent relay in the wall that the 1-wire can switch and that the spur is wired in to to keep the power local to the ufh rather than running all the way back to the cabinet? Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 21, 2023 Share Posted June 21, 2023 58 minutes ago, Thorfun said: resurrecting this thread as i'm currently looking at this. our tiler is installing the electric ufh mats in our FF bathrooms. i'm installing a Loxone system and have run cat6a to our AC units and GF UFH temp sensors for 1-wire control so could easily extend that loop to include the electric ufh temp probes on the first floor. my question is would the power for the electric ufh have to run all the way back to the loxone cabinet? with a standalone thermostat/controller we could run it as a spur of the ring main. or is it possible to put some form of independent relay in the wall that the 1-wire can switch and that the spur is wired in to to keep the power local to the ufh rather than running all the way back to the cabinet? What outputs can the Loxone give? Zero volt switching or 230v out? How many amps per 'channel' etc? The UFH mats will be using very little power tbh, so just treat it as a lighting circuit and run from the 3a switched fused spur (you'll need to retain a means of local isolation) back to the HA cabinet? Saves a relay, but the relay may be the cheaper option. Just remember to go solid state, or you'll have clicking noises coming from the relay which may have been better left at the HA cabinet Link to comment Share on other sites More sharing options...
Thorfun Posted June 21, 2023 Share Posted June 21, 2023 3 minutes ago, Nickfromwales said: What outputs can the Loxone give? Zero volt switching or 230v out? How many amps per 'channel' etc? The UFH mats will be using very little power tbh, so just treat it as a lighting circuit and run from the 3a switched fused spur (you'll need to retain a means of local isolation) back to the HA cabinet? Saves a relay, but the relay may be the cheaper option. Just remember to go solid state, or you'll have clicking noises coming from the relay which may have been better left at the HA cabinet afaik Loxone can do anything! (i've not started building my Loxone cabinet yet and so my knowledge/research is from quite a while ago) the way i see it Loxone doesn't send the 230V per-se there is a relay in the cabinet that is wired to the mains cable via jumper blocks and so when heat is required the Loxone miniserver sends the signal to the relay in the cabinet (probably on the same DIN rail tbh) and that then turns on the power. that way it's easily configurable to allow that cabinet relay to be rewired to trigger something else in the future. @joth, @Dan F, @Rob99, @jack and others are very much more experts on Loxone than me! but i'm hoping my knowledge will rise dramatically as i get closer to wiring up my cabinet. 😉 Link to comment Share on other sites More sharing options...
Thorfun Posted June 21, 2023 Share Posted June 21, 2023 further to the above i guess i could ask the sparkies to run a 1.5mm cable to each locally isolated switch outside each bathroom. should be pretty trivial for them at the moment. Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 21, 2023 Share Posted June 21, 2023 1 hour ago, Thorfun said: further to the above i guess i could ask the sparkies to run a 1.5mm cable to each locally isolated switch outside each bathroom. should be pretty trivial for them at the moment. Yup. Don’t put the switches / spurs at the bathrooms, they look ugly! Hide them in an adjacent room or cupboard / closet etc. Link to comment Share on other sites More sharing options...
Thorfun Posted June 21, 2023 Share Posted June 21, 2023 1 hour ago, Nickfromwales said: Yup. Don’t put the switches / spurs at the bathrooms, they look ugly! Hide them in an adjacent room or cupboard / closet etc. that's actually quite tricky for us! we don't really have any cupboards that close tbh. we have the ufh and towel rails to spur. It will be a conversation I have with the sparky. Link to comment Share on other sites More sharing options...
Pocster Posted June 21, 2023 Share Posted June 21, 2023 30 minutes ago, Thorfun said: that's actually quite tricky for us! we don't really have any cupboards that close tbh. we have the ufh and towel rails to spur. It will be a conversation I have with the sparky. I put mine in in the loft near the access hatch . Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 21, 2023 Share Posted June 21, 2023 50 minutes ago, Thorfun said: that's actually quite tricky for us! we don't really have any cupboards that close tbh. we have the ufh and towel rails to spur. It will be a conversation I have with the sparky. Stick them low level next to a hidden double socket. At least they blend in / are out of eyesight then Link to comment Share on other sites More sharing options...
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