back to article Heatmiser PRT-TS Wi-Fi RF thermostat

With fuel bills ever rising, keeping an eye on your heating makes good sense, and Heatmiser’s Wi-Fi thermostat is intended to help you do just that. It’s based around a large, 3 x 2.5in touchscreen, which controls a timer/thermostat with its wireless features enabling configuration from an iOS device. Heatmiser PRS-TS WiFi RF …


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  1. AndrueC Silver badge
    Thumb Up

    Sounds interesting but the 'warming period' seems a bit naff. My five year-old thermostat has optimum start so it works out its own warming period - anything up to three hours if I remember correctly. My thermostat also has a module fitted that sets the clock from the national radio signal.

    I like the graphing through and I suppose that web control might occasionally be useful.

    1. Gonebirdin

      Optimum Start

      You can set the warm up period from 1 to 3 hours in the config settings. The unit does work out how long it takes to raise the room temp by 1 degree so if you set it to 3 hours it will switch on anytime within this period

      1. AndrueC Silver badge
        Thumb Up

        Re: Optimum Start

        Ah, right. Thanks for that.

  2. Anonymous Cowbard

    Considered this, bought a Honeywell instead

    The thing I don't like about this system is that you have to mount two boxes to the wall.

    I have a Honeywell CM927 which I prefer as I can move it around the house and the RF receiver fits on a standard backplate with no need to recess a box into the wall.

    If you've an existing, surface mounted 'stat I can't imagine it's easy to cut a recess into the wall without risking cutting the cables. It's certainly going to be a harder job than replacing a standard room stat.

    Being able to move the thermostat about means that I can put it in the kids room at night and be sure the temp won't drop below a minimum value.

    Being non-movable, for my usage, is a massive downer on this unit.

    1. Nigel Whitfield.

      Re: Considered this, bought a Honeywell instead

      I certainly had a bit of fun installing the wall box, but more because of the horrific state of the wiring in my flat. Never drilled through a live cable before...

    2. Heatmiser UK

      Re: Considered this, bought a Honeywell instead

      Putting wifi in a battery stat would mean recharging often. If you don't need app or remote control, we would also advise a moveable wireless stat. We have that series in our range also (WTS series)

  3. Anonymous Coward
    Anonymous Coward

    Don't need a fixed IP

    Most routers support a service like dyndns so even if your ISP gives you a new IP you'll still be able to access remotely.

    1. Nigel Whitfield.

      Re: Don't need a fixed IP

      Yes, you can use DynDNS, but you'll need the thermostat to have a fixed IP on your home network, is what I meant, rather than letting it configure via DHCP.

  4. CuriousChicken


    So what this is is a pretty bog standard wireless thermostat which you can control from a web browser. Personally, my requirements to set my central heating when I'm out of the house are limited. And fortunately for me, I can easily access my control box. If this can be developed to give smart multi-zone control then maybe it's worth looking at. As it stands you can get 95% of this functionality at less than half the cost.

    1. Nigel Whitfield.

      Re: Convergence?

      It will work with the Heatmiser multi-zone systems, yes; so it can be a part of a much larger setup. And obviously, if you don't need control from outside, then it's likely to be overkill.

      On the other hand, if you do work irregularly, that ability to control stuff can be jolly useful, turning on the system when you leave a job, and so forth.

    2. Jan 0

      Re: Convergence?

      > requirements to set my central heating when I'm out of the house

      This is exactly what I need. When I decide to work late, or go out for the evening, there's no point firing up my boiler that evening, so being able to override it will put save beer tokens. Similarly, when I'm sent home early because it's snowing, I can make sure I get home to a warm house. What's not to like?

  5. Joe Carter

    +1 for the Honeywell CM927. Great bit of kit that also has a learning warm up mode.

  6. Thomas 18

    Seems dangerous

    Hackers could break in while your asleep and override the safteys, literally BOILING... YOU... ALIVE...

    I'm going to write to fox news, suggest they do a piece on this threat.

  7. Anonymous Coward
    Anonymous Coward

    £200 ?

    You're having a laugh. Who the hell spends £200 on a thermostat?

    1. Anonymous Coward
      Anonymous Coward

      It's not any old thermostat.

      It's an Apple-compatible thermostat. £200? No problem.

    2. Anonymous Cowbard

      Re: £200 ?

      With the Honeywell CM927 available for between £90 and £130 (eBay to Amazon price range) you really have to want the iPhone integration for it to make any sense.

      Anyone looking for a proper home automation job won't look at this anyway they'll buy something that integrates with existing HA protocols.

    3. Mage Silver badge

      Re: £200 ?

      Apple users.

    4. Nigel Whitfield.

      Re: £200 ?

      If you want something remotely controllable, you'd pay a similar price for, say, the Hortsmann Z Wave thermostat (around 130-170, plus the cost of the actuator to switch the boiler; then add the cost of a separate Z-Wave controller if you wanted to provide remote access via the net).

      You could do things cheaper if you opted for X10, though you'd still need to add a gateway for remote access; you could spend a lot more if you went for one of the GSM heating interfaces too.

      If you're going all out for a full home automation system, then you might have a controller/gateway already, and can add a separate thermostat. But what you have here is all you need to do it, and for some people that's worth paying for (and, of course, if you do have a three wire connection, for a stat with a compensating heater, you can save £50 by not getting the RF version).

      Yes, if you don't want the remote control, then it's a lot to spend. But if you do want that functionality, the price doesn't vary massively from some of the other ways of achieving this.

    5. miknik
      Thumb Up

      Re: £200 ?

      I know right? Who the hell spends £1,000 on gas either? Oh wait, I do every year.

      This will pay for itself in no time, perhaps not for you but I'm not on the 9-5 so being able to switch on the heating as I leave for home rather than rely on a dumb timer is a real money saver.

  8. John Robson Silver badge

    Need very low price/power thermometers (in a plug maybe)

    Then I can put any PC (or an RPi) under/near the boiler for control purposes.

    It'd be nice to have WiFi based valves - that report temperature and how open they are - then the whole lot could actually be configured decently - none of this "whole house" heating based on crudely set thermostats.

    It would be even better if they were really low power radios, and had a little solar panel to charge from during the day or evenings with the lights on.

  9. Charlie Clark Silver badge

    Better insulation required

    Looks like your flat cools down pretty quickly. Better spending the money on better insulation or a more efficient boiler.

    1. Nigel Whitfield.

      Re: Better insulation required

      Yes, it does indeed - that's one of the things I've noticed since being able to graph; the boiler's actually only two years old, and is very efficient. However, the single glazing not so (and the least said about the hideous louvre windows the better!)

  10. TRT Silver badge
    Thumb Up


    I can see an application here for shift workers, if it can integrate with events in the calendar. And as it's got an open source project going for it, that could happen. Pricey, though. They could have integrated a small webcam and mic for that price and made it a home surveillance device as well.

    1. Nigel Whitfield.

      Re: Hmm...

      That's one of the things I'm looking at doing. I've just been playing with some location stuff on my phone so that I can do a simple "Nigel is at home", "Nigel is at Vulture Central" query, and though straightforward geo-based control of the heating is a bit problematic to sort out on a logical basis, on days when I do have to be elsewhere, combining calendar info and location may be a good way of deciding when to trigger heating switches.

      The code we linked to here includes a simple example script that reports the status, and it's pretty straightforward to send the commands to switch between 'home' and 'away' modes; I'll try and post those on my blog later.

  11. Mike Parris

    £200 ?

    The big (unique at the moment I think) feature is that you can change your heating settings from your couch using your PC or phone. I fitted one of these when they first came out and find it really useful. I live with Ms Sceptical and even she is impressed.

    1. Anonymous Cowbard

      Re: £200 ?

      But with a Honeywell or similar you can control the heating from your couch too, with fewer holes made in the wall and for less money.

      My mrs is also a techno-sceptic but loves our Honeywell so much that we had to fit a new one when we moved home.

  12. Anonymous Coward
    Anonymous Coward

    we have 3 heatmisers in our house. 1 fixed thats does HW and 1 UFH zone and 2 of the RF versions of this (like this but without the wifi) that do two otehr zones. They are pretty good and I might consider changing one of them for one of these but not sure if it would be worth it. I take they both use the same recevier?

    1. Nigel Whitfield.

      The manual says it works with the RC1-W and UH1-W receivers

      1. Bob H

        While you are being helpful...

        Hi Nigel,

        Great article. I've been looking at heatmeiser for a while, but I didn't realise their wifi units used separate switching unit from the head unit, a revelation they really need to make clear on their website! I'm almost convinced to buy one, although I like the American 'Nest' thermostat unit for functionality, but they can't tell me when it will support mains switching.

        I was wondering if it was wireless-ly compatible with any of their electric under-floor heating thermostats? This would put me over the edge because my bathroom is with UFH but I don't fancy running new cables to link it to a wiring centre. I'll owe you a pint if you solve my dilemma!


        1. Nigel Whitfield.

          Re: While you are being helpful...

          Some of them, like this one, use a remote switch; it's the first of their wifi ones that does, and is new, which is why we did the review. If - like quite a lot of people in the UK - you only have a two wire connection to your existing thermostat, the models that have the switch built in are a fiddlier replacement, because you'd have to pull a new cable through the walls, as they need at least a three wire connection (L, N, switched L return).

          I do know that the settings include options for external sensor and floor limit, though they aren't applicable to this particular model, and I suspect they're because it's a common firmware base across several models. You may have to wait for them to do extend the range a little.

        2. Heatmiser UK

          Re: While you are being helpful...


          The models on the web are switching from the main unit. Once we launch the new rf model we will update the site.

          We are working on a new floor heating model of the wifi stat, but that will be switched from the main unit. We will then, based on demand, look to offer a rf model with connection of the probe to the receiver.

  13. Synonymous Howard

    Or build your own ...

    I have plans to build my own controller using a Raspberry Pi which will ..

    + control the boiler, valves and pump using the GPIO interface (s/s relays, push-buttons) to existing 'manual' controller

    + web interface/dashboard (iPhone/iPad/Android compatible) for remote control and graphs etc

    + keep history of on/off states and link to my one-wire weather station for both inside/outside temperature/pressure

    + using tha data implement a learning function of manual usage plus a form of auto-control based on weather forecasting (e.g. from both own weather station and wunderground 'local' forecasts).

    Should keep me busy for a few months.

    1. Anonymous Coward
      Anonymous Coward

      Re: Or build your own ...

      PIC chips would work better. You're just programming a state machine anyway.

      1. Synonymous Howard

        Re: Re: Or build your own ...

        All computers are state machines at their heart 8-)

        PIC based solutions are relatively complex to do and really not that cheap for hacking compared to the general purpose Linux-based Raspberry Pi where you have no end of choice of programming / script languages and you get the extra grunt to run daemons and perform complex development tasks all without a host PC ... you also get access to many more interface options through the built-in ethernet and usb connections. Plus the Broadcom SoC in the Pi gives a good collection of GPIO pins for hardware interfacing []. All that for $35 + vat + delivery (but please don't all rush out and try to buy any next week as I want at least 3 !)

        Another interesting cheap alternative is the AtMega168 based FIGnition [] running Forth and you build it yourself (in <2 hours) .. runs off usb power supply and works really well but is sadly lacking in GPIO pins 8-(

  14. Kirbini

    Nest for me

    If your read about the Nest thermo controller you'd find that all these new gadgets are just the sam old thermos with som fancy new access methods. The Nest pays attention to your schedule, how many people are in the house, and a bunch of other stuff and automatically adjusts temps to your preferred time and temp. Pretty ingenuous really.

    But I'm getting the impression that you in the UK are tied boilers and radiators still. That true? Is that why @Nigel says he wont get a Nest until it supports "mains switching"? (I don't even know what that is.)

    Us Yanks tend to use natural gas fired forced air furnaces or electric baseboards for heat. These be be somewhat less fiddly than proper boilers and such. Anyone care to illuminate?

    1. Anonymous Coward
      Anonymous Coward

      Probably 95%...

      ... of central heating installations in the UK are gas boiler and radiators.

      Given the amount of gas there was in the North Sea its been very very cheap for the last 40 years - it still is in European terms.

      Apart from the north of Scotland there are few places in the UK that require the level of heating northern US states do in winter. That's why UK houses are so hideously inefficient re energy usage, its never very hot or very cold for long.

      1. Kirbini

        Re: Probably 95%...

        As I sit in my office on the Northern Great Plains and watch the first inch of (a predicted) 7 blow horizontally past my window, I am pleasantly reminded by Mr. Naismith that indeed, there are places in the world where winter is not 6 months long.

        I shall keep visions of your warmer climes in my head while I shovel myself out of a ditch later today.

  15. JimmyPage Silver badge

    Windows Phone app ?

    Let me guess ...


  16. Anonymous Coward
    Anonymous Coward

    Two wire vs three wire?

    "you'd have to pull a new cable through the walls, as they need at least a three wire connection (L, N, switched L return)."

    Er, unless I've misunderstood something, to replace a two wire stat with a smartstat, you don't need to pull any new wires, all you need is a smartstat which is capable of being battery powered. Like mine is. I forget which one it is, but it does more than enough for me.

    You get me?

    1. Nigel Whitfield.

      Re: Two wire vs three wire?

      Yes, indeed; my previous programmable stat was battery powered. But that's rather less practical if you want one that has wifi and a fancy touch screen.

      While my old Drayton Digistat would run for years on a PP3, I don't think that would cut much ice with wifi. You might be able to use low power radio, I suppose, and have the wifi powered from mains in the remote relay, though.

  17. Anonymous Coward

    Is it truly self contained?

    Is it truly self contained? By that, I mean "does it work without the need for an external web site?" I have a Filtrete WiFi thermostat, and while you could say it has a built in web server, that is only used to set up the WiFi WPA2 PSK - once that is done, you don't talk to the thermostat directly, but rather to the Filtrete site. Your thermostat then polls the site every couple of minutes for any configuration changes (and updates the site with data such as temperature).

    The "advantage" of this approach is that you don't need to do anything with your firewall (you DO have a firewall between you and the Internet, don't you?) other than allow the thermostat to access a web server (which most SOHO firewalls do by default) - no need to allow externally initiated traffic to reach the thermostat, which makes it much more Granma friendly.

    The disadvantage is that should the company go away, your thermostat won't work. AND you have an external entity that now knows when you are away, and can make a pretty good guess about your sleep/wake habits.

    I looked at several WiFi thermostats, and I saw none that actually hosted their configuration pages themselves - all the ones I found used the "pull stuff from an external web site" model. I settled on the Filtrete because a) it was reasonably priced and b) it was available at my local DIY store.

    1. Nigel Whitfield.

      Re: Is it truly self contained?

      Yes, it is self contained; you talk to the stat on port 80 and you can do everything you want; and if you want to integrate it with other kit, or use the remote apps, those talk to it on port 8068, using a protocol that's documented on the Heatmiser site and is essentially the same as their networkable models

      (So, someone could write a Windows Phone app if they really wanted).

      There's no reliance on an external site at all

  18. Tanuki
    Thumb Down

    Thermal Mass

    Tanuki Towers has sufficient thermal-mass to make such things irrelevant: if I turn the heating off altogether I lose about 0.5 Centigrade per hour; running flat-out the oil-furnace and both woodburners can push the temperature up by about 1.5 Centigrade/hour, making "turning the heating off overnight" a complete waste of effort.

    Thermostatic radiator-valves are wonderful.

  19. Phil O'Sophical Silver badge


    Does the browser interface support a more secure login than simple username/password? If I'm going to expose my CH system to the internet I'd want at least a decent SSH passphrase-based login. Having to tunnel though my server just to get adequate security would be a pain.

  20. CW

    Excellent Geek value

    I've had one of these for six months or so, it's a three wire model so one box on the wall. I have endured endless piss taking from those who don't get it but I think it is great.

    I live in a fairly new build flat that is very well insulated. It warms up very quickly and it has to get very cold outside for the temp to drop very far. However, previously only had a manual wall stat and no timer fitted. Now I have my heating set to come on for half an hour in the morning, so it's warm when I get up. Then on my way home from work I check the temp via my iPhone and fire up the boiler for a short blast if it has got slightly chilly during the day.

    The biggest issue I have faced is getting my Airport Extreme router to work with DynDNS, as it uses the DNS Update [RFC 2136] protocol combined with TSIG security [RFC 2845] rather than Dyn's APIs. It works fine for 5-6 days then reliably wipes out the DNS record, requiring a reboot. Bit rubbish, like most Apple kit when you dig into the details in my experience!

  21. Rickenbacker
    IT Angle

    How many wires are needed?

    The article mentions two versions, one requiring 2 wires and another requiring 3 wires. The Heatmiser website says that "Providing your have at least three wires, excluding earth, then you can upgrade your existing thermostat to our DT-TS or PRT-TS WiFi Thermostat." Three wires + earth is four by my reconning. They go on to say that "4 wires are required for our PRTHW-TS WiFi model."

    Having just opened my old (1989 or thereabouts) thermostat, I can only see three wires INCLUDING earth.

    Confused in Finchampstead...

    1. Nigel Whitfield.

      Re: How many wires are needed?

      The models currently on their website require 3 + earth (though, actually, there's no earth connection on the state; I wouldn't recommend re-purposing your earth wire though...)

      The model I reviewed will work with a twin+earth connection, leaving the earth connected to the wall box, and is "PRT-TS WiFi RF"

      It's due to be generally available in March so presumably their web site will be updated at that stage.

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