deezell wrote: » First thing, if your motorised valves are burning out motors, perhaps the valve is sticking and straining the motors. Replace the entire valve. They're cheap enough. The Tado ext. kit in two zone mode, HW and CH, sends a live for either event. As you have no HW motorised valve , I assume HW is gravity fed, or by the pump, and HW is always heated when the boiler is on, regardless of which zone valves are open. In this case it's simple. The HW switched live (SL) from the ext. kit is connected to the boiler, the CH SL is connected to its zone valve, whose built in relay sends SL to the boiler. You'll need a second tado stat for the upstairs zone. This will also need to control its zone valve, which in turn calls the boiler. All three SLs are combined, the SL for HW an the two SLs from the valves, but NOT the CH SLs from the stat or the ext kit, otherwise all valves would open for any event. Smart TRVs on some rads can be effectively used to call a zone from a room that cools quicker than the usually centrally located main stat. Ordinary TRVs can be used to cap heat in other rooms in that zone. Smart TRVs can be used to take out rooms in the zone not needed when the main stat for that zone triggers. One or two smart stats is a 5-6 room zone ( upstairs 4 bed house say), can be used to great effect to heat certain rooms above main landing stat setting, or to take out a little used room during a heating time Interval. Ordinary TRVs on other rooms will cap them from overheating, but don't put an ordinary TRV in the area of the main stat unless it's set to above the stat set temperature, so the rad can heat to the temperature set on the stat and turn off the boiler. Be aware that smart TRV motor noise in bedrooms can be disturbing to light sleepers. Final note. As you have no stats, the ext. kit will give you one wireless stat, but you will have to wire in the other back to its zone valve. If this is a pita, consider drayton wiser, or hive where all stats are wireless, you just locate the receivers next to the motorised valves. Both of these have TRVs in their portfolio, I'll leave it to you to check homekit compatibility.
paulgrogan.eu wrote: » Wow Deezell this is amazing stuff, thank you. So to answer a few questions there: You could be right about the sticky valves, and given the quality of the Heatmerchants units we're probably going to change them over to Honeywell units, so no issues there. While the system is drained down, we are also going to add a third to the hotwater tank pipe, so that will, for all intensive purposes, give us 3 zones, Upstairs, Downstairs & HW tank. Regarding the HW, yes, once the boiler is on the best I can do is manually turn off upstairs/downstairs rads and then I get hot water heating only/always. That's unstoppable. My tank is upstairs so I'd imagine it's pumped up from the boiler. Does Tado measure the temperature of the HW? Or does it just heat all the time? Is there a boost option for the HW with Tado? Thanks for the notes on the smart TRV's, that pretty much all stacks up alright, and I see where your going there with the layout. My logic in my head at the moment is to go with 8 in our most common rooms, and then set the older TRV's lower in the less common rooms just to keep some basic heat in them. Obviously long term the plan would be to use smart trv's on all rads (we've got 15 rads in the house). So no, we've no stats at the moment, but I didn't realise Tado only allowed 1 wireless unit. This isn't really a big deal, as I was planning to locate one stat (now the wireless one) in the kitchen (3 rads in there) and then 1 on the upstairs landing, which could be put outside the hotpress which has a direct route down to the boiler area, so wiring that would be pretty simple. Regarding the Drayton stuff, I can see they are a good bit cheaper (forget the Homekit compatibility for a moment). How would you rate them compared to Tado for example? Thanks a million for your help, this is exactly what I needed. Paul.
paulgrogan.eu wrote: » Does Tado measure the temperature of the HW? Or does it just heat all the time? Is there a boost option for the HW with Tado? Paul.
deezell wrote: » No, but you can wire a simple mechanical stat fitted to the HW cylinder into the ext kit HW SL output, this will cut the boiler when the cylinder reaches the temperature on the stat. Otherwise the HW will heat until it approaches the boiler temperature, at which point the boiler will cycle on/off until the HW timer event ends. The Tado app has boost for all zones, just tap on the zones display to enter manual mode and the default duration and temperature (ch zones) will show. Duration can be a preset time, at the next scheduled event, or manual end by user.
paulgrogan.eu wrote: » That's mega stuff and a nice note about the additional mechanical stat, I did wonder where Tado measured the HW temp. Does this show in the app? I can't help but feel that this element is pretty essential to prevent the system just heating the water over and over for the sake of it. Thanks for the note on the boost. So when you say boost a zone, I assume a zone can be a single TRV for example (if connected to a single rad in a room and setup as a room) and then only that room gets a heat increase but the others (either on mechanic or smart trv's) just stay as is?
deezell wrote: » Tado doesn't 'know' the HW temperature. Tado just provides a timer schedule for HW events. These are basically boiler on/off, the mechanical cylinder stat can be added and set to your preferred HW temperature so that the boiler will cut when the HW reached target temperature. The Tado system has no feedback of this. Some posters here install 3rd party cylinder stats with web access, such as SonOff, and with this you can see what temperature your HW is at, and change the trigger temperature for whatever reason. I said this many times before on this forum, turning HW on and off is a relic of our obsession with turning off the immersion. If you have a modern deep insulated cylinder, you don't really need timed events at all, just a thermostat on the cylinder to call the boiler to top it up. Once heated, the boiler switches off, the HW remains heated for days. The cost of keeping this hot store is trivial due to the low heat losses of these cylinders. If you have a bare copper cylinder with a raggedy arsed lagging jacket down around it's ankles, then you are losing heat at a vast rate. The best smart heating investment you can make is to replace this with a modern one. You'll always have HW, no timers or meddling, and you'll save a stack in oil or gas. Fwiw, tado can only report HW temperature when connected digitally (OpenTherm), and only from system boilers with direct HW heated on demand, with no cylinder storage. The only smart stat system I know off that has a system read cylinder probe for temperature is the Honeywell Evohome, pricey but loved by some. In relation to boost on the app, it's zone by zone as you say.
budhabob wrote: » so.....just on this. I have a nest set up, but put a stat on the cylinder when we go the bathroom done this year. As we're a terraced house, this means that occasionally the boiler kicks on during the night upsetting sleep. Can anything be done to limit the hours of use (i appreciate highly unlikely but said id ask)
Nokia08 wrote: » Sorry I got no notification that this thread actually updated. Timer functionality is minimal it basically just runs as a clock to turn on or off the heating system. And like I had said we only use the on/off feature to turn on the heating when we are in the house. Thank you - I will look into this. Having the dual step up would be awesome!
deezell wrote: » I said this many times before on this forum, turning HW on and off is a relic of our obsession with turning off the immersion. If you have a modern deep insulated cylinder, you don't really need timed events at all, just a thermostat on the cylinder to call the boiler to top it up. Once heated, the boiler switches off, the HW remains heated for days. The cost of keeping this hot store is trivial due to the low heat losses of these cylinders.
The_Scary_Man wrote: » Hi Deezell, I just moved in to a house that has a 3 zone (Upstairs/Downstairs/HW) system with solar panels for heating water, along with a stat on the cylinder. I'm still trying to get my head around how to best use the system. As you say, I'm from the generation that has a primal fear of heating water that won't be used immediately. With the system we have is it then better to leave the HW on all the time? I presume that it will just heat up water then as it is used? Even using thermostats to control the temperature in the two CH zones, I'm resistant to leaving the heating on for long periods of time. I still do what I've always done which is schedule the heating to come on in blocks of time rather than relying on the stats to manage the boiler. Is this a very inefficient way to use this system?
deezell wrote: » A HW tank like yours is very efficient, so just set the stat and it'll heat up as required. The savings from letting the tank cool until a scheduled timer slot are trivial, and you run the risk of having a cold tank of water while you wait for the next timer slot to kick in. Worst case is the risk of bacterial growth if contaminated cold water (as we've had) enters a warm but not hot tank, ideal for bacterial growth. Back in this thread or maybe another one on AV forums I done the maths on a typical 200l tank set at about 65°, and the daily cost in oil for the lost heat was measured in cents. If you want you can stick a bit of that black pipe insulation on the rising HW pipe, and on the side flow pipes, that might save you a further few cents per day, equivalent to boiling a kettle or two. For CH, smart stats make it so easy to be efficient and comfortable, because you don't just set on/off timer events for the heating, you set timed thermostat events, so the stat is automatically adjusted warmer and cooler to a schedule. Typically, 21° just before rising, 18-19° daytime if someone is at home, less if house empty, 16-19 at night time, or even lower. Geolocation mode can be used to turn it off completely or to a tick over temperature also when no one is home. Set up your schedule and tweak it till you're happy, but adjust the temperature as well as the timer.
paulgrogan.eu wrote: » So taking this comment about the HW into account, and also the chat with Scary_Man below, what your saying here is to put a mechanical stat on the tank, set that (manually I'm guessing?) to say 65deg (again using your example with Scary_Man) and then Tado will just read that and call for the boiler to heat that HW zone as required to maintain the hotwater tank at 65deg? So in essence, I should always (12 months of the year) have a full hot tank of water courtesy of the boiler/calls from Tado, and thus not really need the boost unless we go mental with baths/showers etc. Cheers
deezell wrote: » Sort of right idea, but Tado doesn't 'read" the manual stat, no device can, only you can, by looking at the dial. What happens is Tado simply turns on a live mains relay to signal the boiler to fire, but this live is fed via the manual cylinder stat, which cuts that live off when the temperature set on the manual stat os reached, and the boiler shuts off. Tado HW timer relay will remain live for its time period, that's all it knows. Nothing smart about it at all, you could use a Christmas tree plug timer for the same purpose. Sure, you can set the times remotely on the app, boost etc, but as I've said, with a fully insulated cylinder, you don't need HW timing, just a live to the stat which fires the boiler when HW is needed. As for boost, it has no function as HW timing is always on. If someone runs a bath the cylinder water will cool and the stat will fire the boiler till set HW temperature is reached, otherwise boiler stays off until HW (very slowly) cools down. One of the ironies of people trimming down HW time intervals is that the cooling HW reserve requires a bigger amount of heat to take it back to target temperature if its been timed off all night, so you're as well to keep it at temperature in small bursts of the boiler, rather than playing catch up in the morning. If you go away for a long period, say a month, nothing to stop you just turning the stat right down if you don't want the minor cost of keeping the tank full of HW while away. All this is predicated on having a fully insulated low heat loss cylinder like the one in the image above. You can just use the ext kit as wireless for the CH stat, or wire the CH stat and not use an ext kit at all, many people just buy the CH smart stat and leave their HW on the manual cylinder stat only.
paulgrogan.eu wrote: » Lastly, I’m a bit surprised that none of the smart systems offer a ‘smart’ integrated HW stat, rather than having to purchase a 3rd party one?
paulgrogan.eu wrote: » Awesome stuff, thank you. As it goes I can’t see that image above for some reason, it appears to be blocked. I’m fairly sure I have that type of cylinder alright. It’s certainly not a saggy lagging jacket type I know for sure. But perhaps you could offer up a picture of what you consider the ideal tank. Lastly, I’m a bit surprised that none of the smart systems offer a ‘smart’ integrated HW stat, rather than having to purchase a 3rd party one?
deezell wrote: » Is the boiler coming on for CH or HW? Is your Nest wired for HW timing control, assuming its a generation 3 or 4 with HW relay on the heatlink, not a Nest E with CH only. Assuming HW timing is wired up, just set the schedule to off during night. If it's not wired up, it's not a big job to divert cylinder stat via heatlink relay.
budhabob wrote: » its coming on for just HW - we put motorised valves in place for it. its a 3rd gen nest, but I cant pull up HW on the app, so I don't believe the HW is linked into it. Its set to the thermostat so just comes on itself.
deezell wrote: » Yes, Scary Man's cylinder picture seems to have vanished. Here's a few. Goodwins, Brooks, others sell these value for money encased copper. These kingspan are high end fully enclosed. As I posted earlier, Honeywell Evohome system has a digitally connected tank stat which reads water temperature to the app and display. Quite high end, plenty of fans of it on here.
paulgrogan.eu wrote: » Ah perfect, I was fairly sure it was the top one I had, but just wanted to be sure. Ah ok, gotcha on the Honeywell system. That looks like a good system too for sure, and I think ultimately I'm torn between Tado & Honeywell. They both feel like very strong systems. They're on the higher end of the price range for sure, but I guess like anything, you get what you pay for. Thanks so much for all your help, this has been so helpful in trying to better understand this whole area. P.
kenco wrote: » Folks any help much appreciated Have a Danfoss controller that runs to heating zones (up and down stairs) and hot water (tank in hot press)... .....Alternative to Hive that will work with what I have (single backplane) or bite the bullet and get a second one wired and go with Hive? Thanks in advance
kenco wrote: » Fair play deezell Its the Danfoss FP715si. Its the back plate that a single Hive receiver would fit straight onto. Hence the issue if I need two receivers (i.e. need to add/replace the backplate)
THE ALM wrote: » If you are so inclined you could set up home assistant with a compatible sensor to achieve this. I have Hive installed which is integrated into home assistant for heating and hot water. I have a 1-wire sensor on the tank which is also integrated into home assistant and I can then use the node-red addon to set up a routine to fire the boiler when the temp of the tank drops.
kenco wrote: » Yes stats upstairs and downstairs, separate zones
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