Home heating automation

In the app, the stat is showing it is off. Is there a tado TRV int his linked linked to this stat using it as a relay to call the boiler? In that case the stat can't cap the kitchen temperature, but the basic could if you turn it down. I'll have a look back at your previous posts, i can't recall exactly what you had intermarriage of zones etc.

If you have a passive trv in the same room as the boiler main wall stat, you would normally have the trv stat set higher, otherwise the boiler might keep running as the stat can't reach set temperature due to the TRV closing the rad before the kitchen reaches target. If your room stat is also acting as a boiler relay for other smart TRVs, then of course it will call the boiler even though it is locally at target temperature. Setting the manual TRV to close only slightly higher than the wall stat will minimise over heating of the kitchen when other smart TRVs call the boiler.

Putting a smart trv in the kitchen is the best solution, hardly extravagant, and will allow the stat to close the kitchen TRV exactly at target, while still calling the boiler for other smart trv schedules. For €60+, it's effectively a plumbed zone. You can also reduce the kitchen schedules temperature in the evenings without it heating when the main stat calls the boiler for other TRVs. The kitchen TRV will be configured slightly differently, with the wall stat assigned as its temperature measuring device, so the kitchen TRV is just a zone valve controlled by it, it's own built in stat unused. Mobile auto fill butchered my last reply btw, I posted without proofreading. Autofill is a pith.

If your existing mechanical TRVs are connected to the valve base by a threaded ring, tado TRV valve heads are a straight swap. The supplied instructions are fairly clear, and if you have to use adapters for other types of valve body, they are supplied. By screwing on the base of the Tado TRV head first, you then only have to position and fractionly

turn the head with a click. The trv head only powers up operationally when the plastic base and body are locked together, whereupon it goes through a calibration routine by fully depressing and releasing the valve body pin. Follow the instructions to add the TRV to your system and app, by scanning in the TRV code.

Thanks. Looks simple enough

you could use a BDR91 but you can not switch any large load with it using the R6660D I have been switching Two Underfloor Bathroom Heating circuits and a 1.5 Kw Bedroom Heater three seperate zones ie three R6660D they are rated 10a and works perfect and all directly integrated in Evohome Schedules etc but no call for heat to Boiler on these Zones

You dont need trv for electric zones they operate like any other zone but no call for boiler as it's not Needed for electric zones

If you schedule both electric and normal zones at same time then boiler is called by normal zones

Evohome user here

Will continue to work if internet down it uses its own internal network does not rely on your wifi

Trvs can do all temperature measurement but if any rads ate behind rad covers or curtains you will need separate room stat

That answers your 2 specific questions but the complication of a dual fired system with a solid fuelled boiler would really need to be carefully designed for safety reasons in event of power loss etc

Thanks for the replies, much appreciated. I have a plinth water radiator on the same circuit as a radiator. At the moment the TRV on the radiator also turns on the flow through the plinth heater. I want to turn on the electric fan on the plinth heater when the TRV calls for heat.

The controller is in this area, so an option might be to have it act as the thermostat for heater and radiator.

I have the R660 bound to the evohome as actuator for electric zone and a DS thermostat as temp sensor for the zone works exactly like ch zone

660 switches the heater on either by schedule or manually from app and heats up to setpoint set by DS exactly like any other zone so it's as smart as all the other zones exactly like a trv zone with external thermostat the BDR relay normally used for zones that don't use trv are the the same they can switch a zone valve but the BDR has no temp sensor you have to use a separate temp sensor but this is very common config with evohome not all ch zones use a trv some would use a zone valve switched by a BDR an electric zone is exactly the same and fully Integrated into evohome and smart

When you are setting up any zone you set actuator which can be trv,bdr,R660 etc

You also select temp sensor for zone which can be

Trv,DS thermostat, Honeywell round thermostat

So a trv is combined actuator and stat but it's not the only option

This is what makes Evohome by far the most well designed heating control system

.

That's similar to other smart systems so, you need a zone stat and a receiver relay for electric zones or even just a stat with a built in relay (current permitting). There's nothing mysterious or unique to Evo about this. If the zone is electric the receiver powers a heater (subject to receiver current capacity) instead of opening a zone valve and thus firing the boiler. Drayton have a relay with 16a capacity, sufficient for a 3kw heater. I'm just wondering if you see my point that a smart TRV which is an individual water valve also has to call the boiler electrically via a receiver relay. If the system allows multiple TRVs to call this one relay, then that relay can't be exclusive to the TRV you want to operate an electric heater or the fan of a plinth heater. Can you pair a TRV twice, to operate the zone valve/ boiler SL receiver, but also an independent receiver to operate an electrical heater or device? It may be possible.

In short, an electric heated zone is possible with most any smart stat system. It gets tricky when you want a stat or a TRV to operate both boiler/pump/ zone valve and an electrical heater or fan. This can only be possible if the receiver is exclusive to a single stat or TRV, so no other stat or TRV will operate the electric device. Also, the output of that receiver is also required to fire the boiler for the TRV call, and this voltage can't be simply spliced to the output of other relays calling the boiler as their live voltage will feed back to the fan, so another mains to mains electrical relay would be required to isolate combined boiler SLs from the live used to operate the device. Zone valves provide this isolation between zones, so a TRV in CH 1 will not open the Zone valve for CH2 or HW, but any TRV in CH1 will operate the CH1 zone valve, so the zone voltage from the receiver is not exclusive to the TRV you want to operate an electric device.

It might look like I'm repeating myself, but NewClareman's request was a very specific case where the electrical signalling from a receiver had to perform two operations. So it has to be exclusive, and isolated from other outputs.

@deezell it appears that Evohome can operate a group of TRV's, with one TRV/thermostat used for temperature monitoring, as a single unit for scheduling purposes. That's why I think it may be possible to add the BDR91 to such a group, as the TRV and plinth heater are in a combined living/dining area.

Having said this I've always liked simple solutions and your suggestion of a pipe stat is perfect for my purposes.

Thanks for sarcasm I was just trying to help someone who's a new user as they said they were only a six month user and possibly not aware of all Evohome capabilities

I look forward to receiving the box of commas

Thanks @deezell , @xL@xl500

I choose the Evohome as I wanted a system that didn't rely on the Internet. It is very unreliable where I am.

From a functionality perspective all I wanted was to be able to schedule the temperature on a room by room basis. I known the Evohome can do more, but I haven't looked in to this. I got a good deal from Amazon and with the current cost of oil it's already paid for itself.

If I was to nitpick, the TRV's are a bit clunky and the control unit a bit small. The latter could be solved by using something like Home Assistant as a front end. I might look at this next winter. (But only if I'm really bored. -:) )

Most of the smarts stats will work to their schedule without internet, or at least can be operated manually or by Assistant/Alexa/Homekit/IFTTT. There's a distinction between working without external Internet and working without any local area network connection. With some brands local network/Internet connection is optional, Nest, Heat Miser. Ember and others. The Internet hub is an optional purchase in some cases. Other brands will work using local connections between apps and the device, Tado for example can be controlled directly by Apple Homekit when the Internet is down but your local router is still up. I think Wiser will work locally also.

and theres another project for some old tablets in my drawer!