Dumb TRVs with call for heat

My mother in her latter years would have snapped my hand off to have such a system. When she was unable to walk or even stand and needed lifting and hoisting from one place to another she relied on visiting carers or me to switch ON/OFF the heating outside of scheduled times. It took her no time to use my iPad whenever I set up a WiFi hotspot. Unfortunately living housing association rented accommodation we were not allowed to tamper with the heating system

As for getting away from apps, lift the lid off the vast majority of modern programmers and you will find the inevitable microprocessor running - a programme. Using the programmer in my mother’s flat was a mare as many of the buttons had multiple functions so easily confused an elderly user compared to the simple user interface on the tablet and what is easier then simply saying “Alexa set heating to 21”

Richard

Not saying anything at all is a lot easier.

The Honeywell system has its own dedicated controller, not an app. Frankly I find the App for wiser much easier to use than the fiddly mechanical controller it replaced, which was hidden it a cupboard behind the ironing board.

Dave

Home Assistant seems to have overcome manufacturer app-based dependency for a lot of hardware, with the added bonus of controlling everything from one app. And once you've made it work through HA, that *is* forever . . .

In some ways I found the HA learning curve fairly steep - remote access certainly. But other things (cameras, heating, lights, solar inverter/battery, sockets, temperature monitors, TVs, voice control etc.) just pop up without any input from me.

But, granted, it's still an app, and if you don't like apps or can't use them for some reason, you're stuffed.

As mentioned here and elsewhere, it seems that some of these app-based systems do have a manual override. My Hive system certainly does - simply a rotating knob on the thermostat housing.

Given that you want to change something, is there an easier way? !!

nib

Pressing two buttons on the heating conroller I pass on the way to the kitchen, is a lot easier. And it means not shouting. And it means one less device (Alexa) which needs batteries charged, or a mains connection.

What would be useful would be a trainable remote. At the minute there's one for the TV, one for the amp, and one for the DVD player.

There are no batteries in the Amazon Echo and Echo Dot. It will respond to a whisper. No need to shout. Because we have Drayton Wiser it will set the temperature in individual rooms. So through the day bedroom heat is off, but if my wife is going to change and prepare to go out she may prefer it on, and so before going up, to give it time to warm she can say "set the bedroom heat to 22" (she likes it warm).

Alexa can also control my TV and lights. My wife dislikes a central light so we have multiple side lights for which its great. I was wondering if there was a DVD player that Alexa could control, but when I searched this popped up:-

I bet that like me, many look for Alexa compatibility when selecting home devices .....

.... which is also why I guess you won't find the devices you are looking for. They are niche devices, with a limited market. I doubt one would recover the development and CE certification costs...

Dave

Yes, and if you have the Smart TRVs you can manually set each one by turning the housing until the desired temperature is displayed on the small screen.

Richard

To me Home Assistant is the epitomy of the brittle tech stack. It's so complicated, with multiple Docker containers flying in formation.

First of all it gets updates every few months, and if you don't stay on the update train then you rapidly get left behind such that it's very hard to get back on. If you upgrade across too many versions, things have changed such that you have to manually go in and fix things that previously worked.

Second it depends on running Linux on some piece of hardware, which increases the likelihood of failure. For example, SD cards wear out. I was running it on an mini PC (so proper NVMe storage, not a micro SD card) and one day after we had a power cut it refused to boot - no lights, nothing. So that was the end of my HA setup.

Third, even when running correctly it could sometimes get confused (eg stop recording data for no reason) and need rebooting. Not good for something you depend on all day long.

(it's not so bad if you are only using it to change the configuration of something that'll run your pre-defined programmes independently, but many uses have HA implement the programme logic itself which means no HA, no programme)

Now maybe I could just get some industrial PC with proper hardware, disconnect HA from the internet and let it run for 10 years. But I think chances are high that it won't make it through without some problems.

(and that's separate from the issues of your particular setup having to interact with cloud services which change under your feet)

Basically HA is fine as a hobby but it's not an appliance, especially if there is nobody to tend to it. It could be that, but it isn't (yet).

Agreed, those are of interest to me. Unfortunately it seems to be hard to determine what level of manual features you can actually do for each system.

(and for other features too - eg there's lots of YT videos on installing the Evohome or Wiser systems, but I couldn't find any showing how their UIs work in day to day use. Which is surely the most important part of how to use them)

Theo

The app usually just provides a fairly friendly user interface. Scheduling my boiler controller for heat and hot water is far easier on the smart phone than the convoluted method I had to go through to program my previously owned smart wireless room thermostat via a few (multi function) buttons. I always had to RTFM every time I needed to re-program the latter as the method wasn't that intuitive.

One thing to consider is can the controller and associated equipment still work without an internet connection? Some of systems in the market place are cloud like operated - the scheduling is not kept local. These systems still allow very basic manual on/off control if the internet/broadband goes down.

It strikes me that some people want all the advantages of modern control methods but are not interested in investing time and money in the other half of that control. TVRs that can be programmed or have other functionality are usually only supported as part of an overall control package. These usually have some bridge or are wi-fi enabled to your router so that they can be user controlled by other devices on your home network or remotely.

My aged mother who now only has partial sight in one eye finds things like smart plugs etc. controlled by voice via Alexa essential these days. Simple voice commands such as phone x or phone y, TV on, change channel to.., lights on, reminders to take tablets etc. means that she can still live a fairly independent life, albeit with carers for a hour each day coming in.

The OPs options seem to be i) put in a larger radiator especially if it's a type 11 that can be replaced by a type 22 or type 33. As has already been mentioned, trying to heat a single room that has an undersized radiator, possibly with an old oversized boiler, can cause rapid short cycling putting mechanical strain on the boiler and will be very inefficient.

Taking a type 11 radiator as the reference a type 21 will output approx

ii) rather than a TVR install a £10 mechanical room thermostat and wire that in parallel with an existing room thermostat. If more control is needed then a smart wireless thermostat (battery operated thermostat transmitting to a mains controlled receiver that could be placed, and perhaps powered, by the existing room thermostat).

I just enter some numbers or press a button on my browser.

The joys of a Linux web based heating controller that adjusts its clock to wintertime automatically...

Mind you the thermometers needed a reboot after a few seconds power cut this morning. Never quite managed to sort the retry loop out or implement a watchdog to protect against that...

I found a (long) video that shows the Evohome controller:

From that it appears to be very schedule based - it expects you to set programmes for temperature at different times of different days. There's a

Can you use it in a completely non-scheduled mode: you're cold, so you want some heat in the room you're in? Can you do that easily? You don't want to set the room up to 24C until 22:35 hours, you just want some heat for an hour or two until you go to another room. How many button presses are needed for that? You can obviously just bump the temperature manually, but do you have to remember to drop it down when you leave otherwise the room stays hot?

Theo

Hmm, turns out it does modulate: 10.6 to 30.1kW.

So it sounds like I need to find minimum 10.6kW of load otherwise it'll short cycle? That could be a pain.

The manual says that when TRVs are in use at least 10% of output should be achieved with a room thermostat rather than TRVs. So I suppose that only needs minimum 3kW of output - which could be more doable.

It turns out the Radbot 1 doesn't have the radio module (RFM69HCW I think is what they use). I'll have to find a 2R to see if it does.

(Radbot 1 has the same Atmega328p controller as on earlier OpenTRV designs and a space for the module to be soldered, but I also don't know if the software is different)

Theo

It is scheduled based and there is no "boost" button on the thermostats themselves. However just turning the room TRV up will call for heat and if you set up permanent schedules which turn the heating down every night this will cover the occasions when you forget to turn the TRV down again. The App does allow you to adjust the temperature in one room (or zone) until a specific time quite intuitively and this can be done from the Controller as well . The thermostats do have a proper OFF position which does not get reset by the controller .

Cycle yes, short cycle - probably not

There is generally too much hysteresis in thermostats. Short cycling happens when the boiler is being commanded for heat but the input temperature is too high. Typically a master thermostat says 'go' but all the TRVs are in fact closed...

Select the room, set the temperature, set "until" (time to revert to schedule), activate ... it takes a few seconds. Done on the controller or on the App. Other options: Eco, custom (summer) schedule, away, day off ... all just 2-3 clicks plus setting the end time. All this will be in the manual so you might want to read it.

I suggest that building your own system might be fine if you need a hobby, but I just wanted heating to work on a room-by-room basis so chose Evohome. Perhaps you also need to consider what happens when you come to sell. Many people would probably be in awe of any smart system, but they'd (rightly) be scared of a DIY system.

Ive never met anyonine yet who on buying a house didn't immediately rip out everything the previous owner had done as well as the original builders, and install their own s*it but...

My stuff is more professional than most plumbers and electricians.

I made my own case, and printed circuit boards.

I am a fully qualified electronic engineer.

If you are scared of DIY what the f*ck are you doing in this newsgroup?

Well, guess what. So does the HP controller box.