Wireless radiator valves.

[Frank House]

The setup I have has been running for nearly 20 years has a single 'zone' for the whole (large) house.

As Steve said, the boiler automatically switches according to demand, it keeps the pipes close to it hot at all times, not a big cost if they are well lagged.

I set it up as an ongoing DIY project over several years, easily done room by room.

Simple 'on-radiator' TRVs for hallways, stairs, rarely used rooms etc.

For nearly all other rooms, I use programmable thermostats placed to sense temperature at shoulder height in a suitable spot and electrically operated controllers ("valves") on the radiators.

The radiators all seem to have a 'standard' fitting which includes the needle valve which actually governs flow. Just unscrew whatever controls it (casually described as the "valve", controller would be a better term) and screw on a TRV or electrically actuated "valve". No need to drain radiator or system for this.

The thermostats I use are by SALUS, just because that is what I tried first, their cost is (at least was) reasonable, and they have all worked so far.

For each room, one can choose wired or wireless connection as convenient. Wireless connections are coded to avoid crosstalk.

The thermostats I use need a couple of AA cells. They last for years and are easy to replace. Caution -- some makes of thermostats have built in batteries which are not replaceable, and the unit must be discarded when these pack up.

For wired connection the thermostat is connected to the mains, and a cable run to the radiator. For wireless use the thermostat's battery suffices, and the receiver unit is plugged (or wired) into a nearby mains supply and controls the radiator "valve".

With a bit of luck there should be no need to lift floors or make (large) holes in walls.

To meet current wiring regulations, radiators should be earthed, and any "wiring in" should be handled by a qualified electrician. Given that, it need not be a big job. It is quite practical to DIY and get it checked, so labour costs need not be huge. George B mentions battery powered actuators, no personal experience, but that would mean no mains connections at all and an entirely DIY setup .

Decent thermostats should have a "holiday" setting -- just one button press. That is as "smart" as I want to get. Not interested in phoning home to get the system running for my arrival, never felt the lack. Makers can be mixed -- no need to pay for a "system". No need for anything to be online, good reasons not to be.

I am NOT an expert -- no responsibility accepted for wet carpets, domestic stress etc.

As for cost, we noticed no great change over the few years the system was introduced, but a great reduction in the hassle of adjusting radiators, particularly when family visit. I reckon that performance (i.e. comfort, cost, and convenience) at the present level would be hard to achieve with manual "valves" only.

Frank.

 

[scholar]

Anyone have any first hand experience of wirelessly controlled thermostatic radiator valves?
The question came up in another thread, but is likely to be lost in the noise.

I don’t have practical experience of these wirelessly controlled TRV’s, but I have spent a great deal of time looking into them (Honeywell Evohome).

Firstly, as to the need for such a setup, this will probably depend on your own building and how it is used - in our case we have an elongated victorian house on three floors where we can only be using certain rooms at any one time. We have had each floor as a separately programmable zone for many years and this works well, but is still inefficient as we need to heat up the whole floor if we want one room (in fact we do set back the TRV’s in the really unused rooms, but it is not practical to run round doing this to the rooms that are regularly used). In our case, the ability to just heat the rooms we want when we want, and keep other rooms at a different temperature or unheated, is absolutely desirable. So as it happens, after years of looking at this, today I am starting the install (so the thread is topical!). All I can do is summarise where I got to.

Firstly, I assume I am correct in thinking that the question relates to using wireless TRV’s in a system where each individual room can call for heat - traditional TRV’s will only enable you to set back the temperature in that room where the call for heat is coming from elsewhere (a zone controller or whole house programmer).

Initially, I planned to install the Honeywell Evohome system (that uses wireless TRV’s) and I planned out the detailed installation of these. I also use elsewhere a Heatmiser Neo system that I am now very familiar with and I subsequently designed an alternative installation to use this system. Both alternatives do the same thing ultimately; in the end, I decided on the Heatmiser system, the main factors being:
- it was much cheaper
- the Evohome system is mostly wireless (wireless room stats and TRV’s), as per the question posed by @John Brown. This would simplify part of the install; however, I concluded that in our case I wanted to avoid having to manage many many batteries; also the configuration looked more complicated as well as risks of dropouts in the wi-fi coverage in our building. The Evohome system was also a lot more complicated re connecting to our existing zone valves etc.
- the Heatmiser system is fully wired (other than it uses a mesh wi-fi system linked to a central hub for control - giving remote internet control) - so it is a sizeable wiring job involving a number of 8-port wiring centres to which each room stat is wired with 3-core and earth and each radiator valve actuator is wired with 2-core. [there is a Heatmiser option of using wireless room stats, but not wireless TRV’s/actuators as far as I know, so you could avoid wiring up the room stats].

I know this is a long way of saying I don’t have the experience @John Brown is looking for (!), but thought I would explain that in my case I decided to bite the bullet and do the wiring for a more easily managed (and much cheaper) system.

But, with a big house, I think individual room heat control is certainly desirable.

Cheers

 

[Spectric]

A thermostatic valve does have control over the boiler, but not in a direct way. In a dumb system, the boiler switches on when there is a call for heat, either on a timer, or a timer and room thermostat control. Regardless of how hot the rooms become, the boiler heats the primary circuit and heat is pumped around the house.

If a thermostatic valve senses the room temperature is too low and opens but the heating source is off due to no demand from the main thermostat then that radiator cannot increase the room temperature. If it was wireless and could turn on the heat source then heating the whole primary circuit cannot be that efficient but as you say retrofitting a fully zoned system is going to be costly and could involve extensive work in someones nicely decorated home.

Another issue of wireless is signal attenuation within the property, I have used foil backed plasterboard in some rooms and this stops our broadband dead in it's tracks, so now use wired CAT 7 sockets rather than the BT repeaters which were hit & miss so another issue to consider. With a fully zoned system you also need to consider not only the overall insulation of the property but insulation between zones which increases efficiency, and control and reduces noise between the rooms.

 

[Spectric]

Do you have any personal experience of them?

I have fitted many TRV's and wired many heating systems but being old school I cannot see the advantage of using wireless in your heating system when a stat controling a zone valve that gives the boiler a demand signal has worked for decades and is proven technology. Yes I like smart pumps and will use technology when it is justified but complexity for the sake of complexity is not in keeping with sound engineering principles of keeping it simple.

 

[John Brown]

All fair comment. In my case, I already have the TRVs, just need to add the wireless heads. So much simpler than plumbing in zone valves. Also, I can't rely on members of my extended family to do anything consistently, other than turn valves to max, in the mistaken belief that the room will warm up much faster. So we end up with empty bedrooms heated all day, while we're mainly in the kitchen or office.
I expect the wireless comms to be a pain - we have a mesh system for the WiFi, which is still fairly patchy.

 

[paulrbarnard]

Also, I can't rely on members of my extended family to do anything consistently, other than turn valves to max, in the mistaken belief that the room will warm up much faster.

This was the core issue in our house too.

A feature in my system is the ability to interface with ITTT. It lets me to set up rules that override things done by other people in the house. For example I have a rule that checks periodically if my youngest daughter has turned her radiator up to max and turns it back down to a sensible level. I have other rules that give rooms that have their thermostat set to frost guard to turn on periodically to heat the room if the humidity is high to prevent mould. Then they turn off again.

 

[PeterSH]

I have the Drayton Wiser system. About 8 rad valves and two room thermostats.

Does what it says on the tin. Have very specific room temperature schedules. Can change things remotely.

Only thing is the valve thermostats aren't hugely accurate, I guess cos they are close to in some instances a drafty floor and by design a hot rad.

I'd buy it again...

 

[George B]

@John Brown

 

[Jonm]

With a new installation you have to have zones, these zones each have a thermostat / timer and control the heat source, a term known as boiler logic. A thermostatic radiator valve can only reduce a room temperature because it has no control over the boiler but in bedrooms it can keep a room cooler than the thermostat setting as some people like hot and others cool.

To have zones also requires more pipework because each zone needs to be independant from the other zones and so a wirelessly controlled thermostatic radiator valve that has been retrofitted to an existing system will not offer full control, but I cannot see any advantage to wireless thermostatic radiator valve.

The point of a wirelessly controlled radiator valve is that you only need one heating circuit, each room is its own zone, independently controlled. So in my house I have 12 zones.

 

[Jonm]

To answer the OP, I have the Honeywell system, 12 zones, new build, works very well. Control is from the home controller, same as using an ordinary controller except that each room can be controlled separately. I can use the app on my phone but rarely do.

One good aspect is that if you want extra or less heat in a room you just turn the dial on the top of the valve and the temperature is adjusted until over ridden by the next programmed cycle. The temperature the valve is set to is shown on the valve led display. Big advantage is that my wife can do it.

I have had problems which the plumber could not sort. I ended up tracing all the wiring and identifying the components. It transpired that there was a “miscommunication“ between the plumber and the electrician. The wiring and programming was for an “open therm bridge”, but an ordinary external temperature sensor was fitted. As a consequence the wiring went to the incorrect terminals in the boiler and the incorrect program in the controller was used. Took me days to find the problem, a few minutes to sort it out, would have been quicker for me to have wired it myself.

It did not help that Honeywell did not seem able to comprehend that I have a four pipe boiler, two for central heating and two for hot water. Honeywell system calls for heating and/or hot water, boiler sorts out hot water priority and boiler temperature for heating. That seemed completely incomprehensible to Honeywell, but they did try and eventually gave me the advice I needed.

Anyway, I now have a system which is working well and I now understand how it works.

I attach a schematic of my system.

 

[Jonm]

I have fitted many TRV's and wired many heating systems but being old school I cannot see the advantage of using wireless in your heating system when a stat controling a zone valve that gives the boiler a demand signal has worked for decades and is proven technology. Yes I like smart pumps and will use technology when it is justified but complexity for the sake of complexity is not in keeping with sound engineering principles of keeping it simple.

I agree with you about simplicity however each room being it’s own “zone” is a big advantage. Bedrooms not In use can be at a lower temperature, lounge only heated in the evening etc has big advantages. Using wirelessly controlled radiator valves I regard as using complexity to increase control and reduce heating bills without reducing comfort.

All these valves do is replace the thermostatic valve head with a motorised thermostatic head controlled wirelessly, it is not rocket science.

 

[Jonm]

Why I need to control my heating when I am out is beyond me.

The wireless bit refers to controlling each radiator individually from a central controller so that each room has ite own programme, unused bedrooms heated less than used ones, sitting room only being heated in the evening, kitchen being heated early etc. It can be connected to a smart phone via the internet but that is not the main purpose of these “wireless” valves. It is all about control of room temperature.

 

[Jonm]

remote trvs will be useful to some, not all.

I think the main function of these wireless trv’s is that each room is its own ”zone” and temperature can be individually controlled. The internet access bit may be useful to some.

 

[NewbieRaf]

Apologies if I missed this as this is a pretty long discussion however it’s important to note that there are a few wireless standards that are used in “smart devices” these days;

wifi - self explanatory- needs power generally cannot be powered via batteries

zwave - low power radio frequency (different frequency depending on country) mesh enabled

zigbee - 433MHz world wide, also low powered, mesh enabled

there are others but it’s get complicated. The more popular protocol is Zigbee as it’s particularly good with long distances (big subject) and you will find that systems such as hive, tado and so on will probably use zigbee (need to confirm).

Since zigbee is a mesh system if you have a zigbee enabled power plug for example it will act as a node within the mesh or in simple terms a repeater, so in essence the more zigbee nodes you have the better your mesh system and the farther is can get. Both zigbee and zwave and many others are best controlled via a local controller or even via the cloud ie. Alexa for example.

hope this helps pls feel free to dm me if you need any additional information. This actually maybe a good subject for my new forthcoming blog - more on that later

 

[John Brown]

Apologies if I missed this as this is a pretty long discussion however it’s important to note that there are a few wireless standards that are used in “smart devices” these days;

wifi - self explanatory- needs power generally cannot be powered via batteries

zwave - low power radio frequency (different frequency depending on country) mesh enabled

zigbee - 433MHz world wide, also low powered, mesh enabled

there are others but it’s get complicated. The more popular protocol is Zigbee as it’s particularly good with long distances (big subject) and you will find that systems such as hive, tado and so on will probably use zigbee (need to confirm).

Since zigbee is a mesh system if you have a zigbee enabled power plug for example it will act as a node within the mesh or in simple terms a repeater, so in essence the more zigbee nodes you have the better your mesh system and the farther is can get. Both zigbee and zwave and many others are best controlled via a local controller or even via the cloud ie. Alexa for example.

hope this helps pls feel free to dm me if you need any additional information. This actually maybe a good subject for my new forthcoming blog - more on that later

Thanks. I know a bit about that side of things too, having written firmware for a LoRa IoT device a couple of years back, and seen numerous discussions about ZigBee on another forum.
So I'm confident with the RF stuff, the electrical stuff, and a bit of plumbing( which I doubt I'll need). I was , and still am more interested in hands on experience of the system, and the sort of savings that might be possible.
Thanks to all who have contributed so far, please keep it coming if you have first hand experience.
Special thanks for posting the YouTube link.
I'm off to the Scilly's for a few days, but will be resuming looking at this when I get back.

 

[MikeJhn]

If a TRV sense's a room is cold it will turn itself up, even if the CH is off, but the pump running the colder water from the radiator will reach the boiler and the boiler thermostat will turn the boiler on, admittedly this may not be a fast process and direct control would be much quicker, I have to think that wireless valves are a solution looking for a problem.

 

[Jonm]

there are a few wireless standards that are used in “smart devices” these days;

I have the Honeywell Evohome system, not sure what standard it uses but the valves communicate with the controller every 4 minutes. Fitted with two AA batteries which last for about one year or a bit more, I have not been monitoring it but I am not always changing batteries. The internal walls of the house are mostly dense concrete blocks and I have no issues with communication. No foil backed plasterboard between the different radio elements so cannot comment on that aspect.

I do have an app on my phone which connects to the controller over wifi but rarely use it.

 

[Jonm]

If a TRV sense's a room is cold it will turn itself up, even if the CH is off, but the pump running the colder water from the radiator will reach the boiler and the boiler thermostat will turn the boiler on, admittedly this may not be a fast process and direct control would be much quicker, I have to think that wireless valves are a solution looking for a problem.

If you look at my post 50 there is a schematic of my system. I have two leds which come on when the system is calling for hot water or central heating so I can see what is happening. If the rooms and hot water are at the set temperature the boiler is switched off. It is only when a radiator valve or hot water calls for heat that the boiler switches on. I have just looked, cold day outside but boiler is off.

I have complete control of individual room temperatures throughout the week and and the boiler only comes on when there is a demand for heat to heat a room or hot water. The boiler sorts out hot water priority and central heating water temperature based on the outside temperature to maximise efficiency.

If a radiator valve senses a need to switch on it sends a signal to the controller which sends a signal to the bdr91 which switches the boiler on and a signal to the valve to open.

I do not regard it as “a solution looking for a problem”.

 

[Jonm]

Why couldn't that have any control over the boiler?

that is how my Honeywell system works, no heat demand then boiler is off.

 

[Boxer]

I also have the Drayton Wiser system. I love it, especially now that they have improved the App. The real benefit is that it makes it easy to instantly turn on and off the heating in any room. So if there's only one or two of you at home then you only heat the rooms you are in. That will definitely save money in the long term.

If you have kids spread about the house then you will have to heat the whole
house all the time and so having it it will be less of an advantage .... unless you want to accurately set specific temperatures and heating times in each room.

Two other points are that despite the TRVs being described compatible with most valve stems this untrue and I had to change all of mine to make it work properly, which obviously added to the installation cost. Other thing is that the WiFi signal from the hub is not so strong and I had to buy a couple of their smart plugs (which act as range extenders) so the hub could talk to some of the TRVs at the back of my modestly sized bungalow.