ablelocks wrote: » anyone? (not tied into Tado either in case anyone would recommend any other options... had spotted their offer on refurbed kits but missed out on that, could wait for it to come up again)
deezell wrote: » Yes it would. Do you have a stat for each CH zone? You would just diy replace these with Tado wired, set the three CH zones on the Sauter to always on, and continue to use the sauter for HW timing. If you only have one stat, that would be odd, and would require a different approach.
deezell wrote: » That sounds right, if the cylinder return goes directly into the back boiler, cylnder flow is by gravity, with no impediment on it's path. The pump comes on for CH and and pumps CH return into the back boiler, joining cylinder return. This tee fitting should be a venturi type, so that the pumped cold return from the rads would 'draw' the cooled return from the cylinder coil, rather than pushing it back up cylinder coil, which would cool it and the HW to a point. This veturi tee may also be fitted where the hot flow out from the back boiler spilits to the cylinder and the radiators. Just a couple, if the rads TRVs are already open on schedule if they are smart TRVs, they will also benefit. You can install smartTRVs to open on a schedule, but without association to a stat to call the boiler. Tado just times HW events, it doesnt have a HW stat in its armoury, you would just use a mechanical cylinder stat. It can only monitor HW temp on direct HW combi boilers which have OpenTherm digital control. Yes, around 60-70°
chris_ie wrote: » As always, thanks deezell. If the back boiler thermostat fires the pump, and the oil runs at the same time, does that not mean the water being pumped would be hot? Its the mixing of back boiler heated CH and oil heated CH water that I can't get. I obviously missing something simple The temperature knob on our oil boiler just shows a ramp symbol, no temperatures. Must check the manual to see what the start/end of the ramp represents.
deezell wrote: » Blending two sources is not always properly done on domestic systems, simple series or parallel plumbimg was common enough, but far from ideal. There are a number of approaches, from simple tee joints on the flow/return coupled to non return valves, motorised valve selection, blending manifolds such as NRG Awareness products (I installed their manifold when upgrading the crudely fitted system originally installed in our house), Systemlink spiral blending manifolds, or more sophisticated chamber/pump devices such as the Systemlink Heat Genie. What you're trying to achive is preventing heated flow from one boiler being pumped uncooled into the other boiler, though either its flow or return pipes. Poor installations wil invariably gurgle and bang, with thermal shock and steam hammer effects. One other simple addition is a relay to cut the oil boiler SL when the pipe stat cuts in. Using the NC contact on tjr pipe stat can achieve this effect. Smart stats will operate and TRVs will continue to operate, but the oil boiler will stay off until the solid fuel source cools sufficiently to turn off the pipe stat.
chris_ie wrote: » Ah, wonder what way they have it done here. The boiler dial we have doesn't show numbers just whats in the image below. Tried checking manual, nothing about the temperature range there. Wondering is it 60-90? (For ages I thought it said LIMIT, only copped on few days ago it said IMIT)
deezell wrote: » As you've probably already seen on Google, there are versions of this stat with 60 - 90 on the decal instead of the ramp icon. I've one of these dual stats in my junk from an ageing '80s boiler I scrapped for a new condensing boiler. I'd had the boiler service tested for co, co2 and nozzle pressure. After the service your man told me the boiler measured about 62% efficiency, so I was spending €500 a year to heat the flue. Out it went asap.
irishgrover wrote: » Hi all, not sure if this is the right question for this, but here goes, apologies if not... I have a oil burning range which supports rads in 2 zones, upstairs and downstairs. I've successfully replaced the various switches with a sonoff 4ch switch. So now hearing csn be automated, scheduled etc etc. All good. Next I got a couple of temp/humidity sensors (WiFi, battery operated, with display screen). Here's the problem. Turns out they only work with the smart life app whereas sonoff use ewelink. So my problem is that I cannot trigger sonoff behaviour based on data coming from the smart life app/sensors. So ultimately the question is, does anyone know of any stand alone battery wifi temp sensors, preferably with display, that work within the ewelink sonoff app.?
chris_ie wrote: » :eek: Jees. We had this boiler installed back in 2015 I think, the other one was all rusted as we has water getting into the small shed/hut that the boiler is in. :mad:
deezell wrote: » 1. Correct 2. Correct Go to the top of the class.
DrPhilG wrote: » I've got 19 rads. Planning to leave the master bedroom on a room stat since it's always the coldest room in that zone. So it doesn't ever need to shut down separately from the others.
Would they be a direct replacement for the EPH cm2's and then would everything work via smart life?
deezell wrote: » They need mains power to function. The CM2s are mechanical stats, they just close a contact, so are 2 wire devices, live in, switched live out. No neutral line to operate the MOES. Permanent live in also required, not an issue once you leave the EPH always on for the CH zones. You can search for a battery operated version, but the problem is, you can't get reasonable battery life from a device operating 802.11 Wi-Fi. That's why all drop in 2 pole or wireless smart stats use a lo power wireless connection (Zigbee, Z-Wave, 6LoWPAN), to a hub. Tado or Netatmo wired will do the trick as direct replacements. Hive or Drayton Wiser or Netatmo wireless with receivers to replace the EPH controller also. If you can get a mains neutral line into the current stat locations, you can use the MOES. Sub is optional on Tado BTW, its for geofence feature, and open window feature afaik.
lausp wrote: » Hello all, Some great info in this thread. I was hoping someone could advise on my situation. I have a vokera gas boiler, and my house was wired for home automation in 2005. The automation was never set up and the wiring just left unterminated in a box in the utility. I've got a sonoff relay running for the last few years for some of the lights in the house which works very well, however I'd love to get the boiler set up too. Here are a couple of pictures of what I have. It's a 2 core cable with both cores brown wires and one live. This, as far as I can tell, is effectively the same concept as the lighting setup where I have live feeding into common, and the switched live in normally open. Can anyone tell me if that is what is going on here with the boiler cable? If so, if I set up a relay/switch with the correct amperage rating, will the boiler stay on while the relay/switch is switched on? Any advice appreciated.
DrPhilG wrote: » Lol, I must have been listening after all.
gfaces wrote: » Yes Deezell you are spot on. I checked the CM2's and they have a single 4 core flex cable running into them. I would upload an image but dont have required posts atm. The flex consists of brown/black/blue and earth. Currently the blue and earth are redundant being taped up.
deezell wrote: » What currently triggers your boiler for CH, for HW. Timer, thermostat(s)? Have you CH Zones? Model no of Boiler. Images of controller/timer/thermostats etc.TLI at the moment to advise.
championc wrote: » With that many rads, it's quite possible that a lack of balancing is leading to that cold main bedroom.
deezell wrote: » A lot of complexity there. Are there individual stats for each zone? How many wall stats in total. Im assuming your entire system is UFH, timing for the entire system is the built in one on the boiler, and it's just this you'd like to automate for the moment. In that case it's possible to connect a volt free set of relay contacts from your Sonoff (com and NO, no mains) into the boiler across two terminals on the boiler which are normally linked, and use this to time and trigger the boiler. I'll take a look for the boiler wiring terminal.
lausp wrote: » Yes entire system is UFH. 6 zones upstairs and 4 stats, 7 zones downstairs with 3 stats. Exactly as you say the whole system is controlled via the boiler directly with either the timer or just turning it on. A stat needs to call for heat for the boiler to fire. Really appreciate your help!
deezell wrote: » Take a look at this manualhttps://www.vokera.co.uk/wp-content/uploads/2009/04/synergy_e_installation_and_servicing_instructions.pdf The control signal for the boiler from the UHF system is applied across terminals 3 and 4 of the Appliance Terminal strip, most clearly illustrated on Fig 41, page 38. This is a volt free connection, like coming from the Allen Bradley relay. If you want to have remote timing of the system, a convenient way to insert one of your home automation relays in line with the boiler call to these terminals, or on the supply voltage of the Allen B relay. You can now set the boiler timer to always on, the stats through the UFH controller will fire the boiler only when the circuit to the boiler control terminals 3 and 4 is completed by a COM to NO relay on your home automation block. I'm assumimg that live is not permanently wired to the Sonoff Com termimals. This will allow you to remotely set On Off schedules for your heating in its entirety. If you require temperature and timed zone control, you will require a wired smart stat for as many of the zones you want to remotely control. Afaik, Tado wired is suitable for UFH control, given the different resonse characteristics of this type of heating. Have a go at getting that spare Sonoff relay into the citrcuit, mains free
lausp wrote: » So unless I am mistaken, reading what you are saying, using the sonoff to just switch the live in the home control box, that will switch the Allen relay to fire the boiler? That sounds like exactly what I was hoping for My only reservation is that the amperage would exceed the sonoff max of 10a per gang 15a max. Edit: actually, just thinking further on this, wouldn't I need to disrupt the current supply to the Allen relay so that the only power source to that relay is from the sonoff?