Home automation - switching the CH on/off

[Rob]

I posted about this a while ago, and didn't get very much further. I was after a simple method of remotely switching the heating on/off via, say, a smart phone.

As it happens I'm having a new combi boiler fitted next week, and asked the installer about building this in. He wasn't aware of any such stuff, but did say a remote socket could isolate the electricity to the boiler, and possibly serve the function. However, he did add that the 'overrun' would be disabled when switched off, and this could be a drawback.

How much of a problem is controlling a combi boiler in this way?

Thanks, Rob

[Newshound]

I don't actually have a "remote", but I have a switch by the back door which breaks the "room thermostat" circuit (I have TRVs so this would normally be permanently bridged) so that it is easy to knock off the heating when I go out for a few hours. So you only need to find a way to break this circuit by phone. More elegant than killing the power (which will stop the timer, if this is electromechanical).

[Rob]

Mmm - yes, good point. Except that I've specified a wireless thermostat!

Rob

[Stephen H]

Google for Heatmiser. they replace the room thermostat and you will need a wireless network access point to the internet. You can then use your smartphone or internet Cafe to adjust the heatmiser remotely.....

Stephen

[Stephen H]

P.S.

[Man at B&Q]

Only the sensor is wireless. The receiver still has to be wired in to the circuit in the same way as a wired thermostat. How else do you think they work?

But that only helps if the thermostat circuit is live, i.e. the programmer is in an ON period.

I would do it by overriding the output of the programmer. That way the overrun is taken care of by the boiler itself keeping the pump turned on.

suggesting you isolating the boiler supply with a remote control socket just shows your installer is an idiot. Maybe it's the same idiot that reversed live and neutral in the supply to my boiler.

MBQ

[Andrew Gabriel]

There's still a 'wired' bit at the boiler.

You might also want to add a low set point stat, so that the heating comes on if the house drops blow somwthing like 10C even when you don't have it on for normal room temperature.

Another way to do this (which is what I did when I first started home automation) is to fix a heater resistor to the thermostat, or in my case, to the thermostat phile of a modulating heater. This works in reverse, in that when it's on, it subtracts a setback of a fixed number of °C per Watt (in my case, 1W knocked about

10°C off the room temperature). I run it from a small low power wall wart with a stepped voltage output, which I used to adjust the desired setback, with the home automation switching the output. Probably not viable with a wireless stat if you're going to be moving it around.

[Dave Liquorice]

Some boilers have the option for a wireless thermostat built in rather than a stand alone receiver module... Makes it harder to modify.

[Harry Bloomfield]

Dave Liquorice submitted this idea :

Maybe this on ebay -

Item number: 170748579755

[Dave Liquorice]

Seems rather expensive and will require a SIM. OK PAYG ones can be had for next to nothing but most will stop working after a while if you don't make a call every so often.

No feedback as to the state of the switch. Not capable of switching mains.

[Terry Fields]

On 3 the credit on the SIM never expires.

My MiL has an unlocked mobile using a 3 free SIM, for emergencies. She hasn't used the phone in 18 months, but the number is active and the credit still shows up in the account.

Terry Fields

[Jeremy Nicoll - news posts]

The credit's not the issue; the provider will take the number away from you and give it to someone else if you show no sign of ever using it. I'd suggest you make a test call from the machine once a month.

Also the provider I have a similar emergencies-only phone with freeze the account if you've made no top-up payments to it in a 999-day period. So plan to add some once every couple of years. At least if you've made some test calls you'll have spent some of the credit!

[Michael Chare]

Something like this would do the job using an additional relay:

have a Barix Barionet which is a more expensive alternative. The Barionet has a port to which I have four Dallas 1 wire temperature sensors connected. This allows me to monitor various temperatures.

I can use my mobile phone to switch the CH on and off via my broadband connection to the Internet.

[Dave Liquorice]

Does 3 have a GSM network? I thought they were pure 3G.

[geoff]

In message , Rob writes

Rubbish - you would be switching the switched live (from the thermostat or timer) to control the boiler on / off. The pcb and associated overruns are powered from the perm. Live

Sack the installer quick he's a clueless idiot

[Mathew Newton]

They are, however outside of the 3G coverage areas they piggyback off Orange's (Everything Everywhere) 2G network.

Mathew

[MM]

You could build your own quite cheaply with Velleman kits from Maplin. You'd need a solenoid that can push the buttons on the wall controller, e.g. one like this:

you send a code remotely to your PC that controls the solenoid via a Basic Stamp, Arduino or similar. So, say you were coming home from sunny Spain and you knew than the temperature in back ole Blighty was freezing cold, you could send the code from your laptop in Madrid to override the programmer and switch on the boiler for an hour or two. You could even write a simple program for the PC to delay the switching for a while.

MM

[Andy Burns]

Haven't been following the thread, so apologies if it's already been suggested, but the Heatmiser WiFi programmable stats can do this ..

asked them about Android support and they said "soon" but that was last year, and still nothing on their website ...

[Andrew Gabriel]

Similar here. I use a combined alarm/home automation unit which gives a large number of progammable inputs and outputs and X10 and direct phone line connection, and I have it linked to a PC which also has a

1-wire bus with several Dallas sensors and the program which runs the heating control, and provides Internet access to the lot.

I've done this in two homes now, and the integration of the heating controls with the alarm (occupancy sensing) together with remote control has given me a much larger saving than any of the energy saving measures which are more commonly talked about and undertaken. Additionally, I get advanced warning of things going wrong.

[Mike Barnes]

Nice idea but it's a timer and thermostat all in one unit, which would mean running three or four (four in my case) wires from the boiler/timer to the thermostat location. You'd think with all that radio technology they could do better than that.