I have looked at different solutions for remotely turning on an electric pre-heater. I don't want to leave it plugged in all the time, and would like more control than the thermostated wall plugs that just go on and off at set temps.

You can buy a cheap simple relay with a photocell and just tape the sensor to a pre-paid cell phone screen. When you call, the light flips on the switch (and heater) for a pre-set length of time.

This I found, which looks to be pretty slick, but $200. http://www.gsm-auto.com/


But I guess China is pumping these out cheap - $37-$50 on ebay.

http://www.ebay.com/itm/New-Fashion-Cellphone-GSM-PDA-RC-Remote-Socket-Control-Power-Switch-dd-/260856200578?pt=LH_DefaultDomain_0&hash=item3cbc3dbd82#ht_9139wt_1110

Might give it a try. Will report.

On both, you can actually just send a text message to the number and it goes on. You can even control/program it this way. Pretty cool. Prepaid phone SIM card plans are as low as $10. They expire in 90 days, so would last you almost the winter in CA. Not quite.

I leave mine plugged in most of the time during periods where I anticipate flying regularly. If I know I can't for a few weeks I leave it unplugged. Electricity is cheap. Just got this email yesterday, makes perfect sence to me. A timer or gsm switch is better than a cold start, but what if you end up not going?

Below is from a lab and it indicates that you should leave the heat on all the time, or, heat prior to startup by a few hours. the key is to have excellent cowl covers as well as spinner and blade covers.

Aviation Consumer actually did a little experiment, testing that long held belief. Guess what, their results contradicted this. They found that the longer the block heater is on, the drier it gets inside the engine. They did leave the oil dipstick opening uncovered.

Sorry Larry, but we have done a lot of cold room testing (granted they were liquid cooled diesels not air cooled lycs) and we found the same thing Orest wrote about below. We tested block heaters, sump pads, heated dipsticks and combinations of all three. We tested in extremes down from -20C to +5C at various humidity levels and winds up to 40 mph. Units were cycled through allowing to cold soak, and then heated 1,2,3,4,5 and 6 hours prior to start. After starting units were brought-up to temp and allowed to run at both idle and under full load for 1 hour. Units were then tested under same conditions only heaters were left on when engines were shut down.

Considerably more condensation was measured inside the crank case, and combustion chambers in the engines that were allowed to cold soak and plugged in only prior to start.

When the heaters were left on (and breathers were kept clean) the engines were for all intents "dry". It was an interesting test that proved a lot of "expert" engineers to be dead wrong.

Basic conclusion was that the swings in internal temperatures is the major contributor to the condensation process. Properly installed block and sump heaters were found to be the most effective solutions, stand alone heated dipsticks were measured to be the least effective.

Biggest risk of fire is potential shorts in the electrical supply cords, not the heaters themselves.
With our setup, I routinely notice CHT and EGT temps of 65F or so, with freezing temps outside. The oil pan heater alone works quite well.


Now, you can get condensation potentially on the outside of the engine block where there is a transition to ambient temperature, if you don't put a good thermal blanket over the cowls. But I am confident that I will not generate condensation inside the engine leaving the heater on continually between flights.

A short preheat and then flying is fine, but what is definitely a very bad idea, is cycling the heater on, and then NOT flying. That will indeed generate condensation.


Mike Busch likes to say that starting an engine with its temp at 0C (32F) is a crime, at -15C (5F) it is a felony. The piston warms quickly when the engine is started, but the cylinder barrel of a cold started engine does not. You get major scuffing and severe wear by the heat expanded piston against the still cold and relatively oil-free barrel.

So in cold climates you really need to do something.

I leave my Aerotherm plugged in all winter (elec. Included with hangar rent).
They are expensive for what they are, but keeps the engine a constant temp.
I flew today and looked at the CHT's before I fired up and temps were between 71 and 75....the Continental thinks it's summer time

I just received my new remote pre heater control and will be using it first thing Monday morning. I went with something easy (for me) to understand, but probably more money then other options. Reiff sells 'em :http://www.reiffpreheat.com/Beeper%20Box%20pg%201.htm. Too many years of being off grid solar powered has broken me of the mindset of "keep it plugged in, electricity is cheap". Though true, and now that I'm grid tied and have power to burn, it just offends my sensibilities to do it so ineffciently, I want control of my pre heating. I can go days and even weeks without needing the heat on and it would just bug me knowing it was on.

Quality seems very high, the plastic box is o-ring sealed and no doubt waterproof, so outside is no problem. While this is a low tech device, the benefit is it is very simple to set up and use. Not setting the right ring tone for the cell phone is the only way one could screw up. For 10 bucks (!) I bought a TracPhone at Radio Shack, complete with chargers (important as the phone will always be ON, and be on the AC charger all the time, there is a plugin inside the box just for this), complete with 60 days of service (I don't care how many minutes as this phone will NEVER complete a call). first I made sure that the available ring tones on it had one with distinct tones, no warbling or other continuous noise type tones will work for the Beeper, you need a ring tone with a brief period of silence between tweets, beeps, or whatever.

Plugging the unit in at home, I noticed a slight hum as the circuity powered up. Oh-oh I thought, this thing itself will be sucking power 24/7 regardless of the pre heater being on or not. Plugging it into a Kill a Watt meter to check it's standby power consumption, I was pleased to see it is less then 1 watt, I can live with that. Once the cell phone is turned on and plugged into the charger, it is velcroed into position near the microphone that runs everything. This is adjustable for sensitivity. Then a simple rotary switch is set to the desired hours of pre heat needed, 1 to 14 hrs I think. Once the box is closed my first phone call was made, and after letting it ring 3 times I hung up. It worked as advertised. If you change your mind about needing pre heat you can call it back and turn it off. One feature I really like is that it is totally and easily portable, with no on site installation, other then plugging it in.

A duplex outlet allows for up to 1800 watts of juice to be controlled. I have mine rigged so that a 1,000 watt pad heater starts warming the oil, a 150 watt flat panel radiant heater in the cab starts taking the chill off, and lastly a 300 watt magnetic heater starts warming the transmission. Another 1,000 watt pad heater powered by a onboard 12 VDC inverter, starts pre heating the hydraulic system once underway.

No transmission in the plane , I got this unit for my crane, which I keep 15 miles away in town. My plane lives at home, in my radiant floor heated hangar 40 ' from my home I still pre heat a bit but just walk over and plug it in, I baby the plane, the crane can tough it out a bit. This did make the expense a business expense anyway.

I know this a very old post but I was looking at different options this morning for turning heaters off and on and found this thread in a web search. Thought I would bring it back up to see if anyone has anything to add, or has something better.
I will mention that my flying has been almost non-existent since I fell last year, so I have been pretty bored and its making my mind wander.

I have a heated hangar. This year, I installed a $80 wifi thermostat. I also purchased a Verizon wifi hotspot which I added to my plan for $10/month. I now control the heat remotely to whatever setting I want.

I know that everyone does not have a heated hangar. However, using a mobile hotspot should allow you to install a "smart" outlet of some sort and be able to control your engine heater remotely.

twflyer wrote:I have a heated hangar. This year, I installed a $80 wifi thermostat. I also purchased a Verizon wifi hotspot which I added to my plan for $10/month. I now control the heat remotely to whatever setting I want.

I know that everyone does not have a heated hangar. However, using a mobile hotspot should allow you to install a "smart" outlet of some sort and be able to control your engine heater remotely.

This was exactly my plan, and one I will get back to once my engine is back in the plane. I have one of those TP-Link outlets for the hangar which I can control and monitor status of using the Kasa phone app, I use a few around the house along with their smart switches. It needs WiFi, so I can either use a hotspot or find a way to get the airport's WiFi into my hangar. In both cases, the metal building basically blocks all radio signals once the big door is closed, so it does require some sort of antenna "repeater".

For cellular this can just be a couple proper whip antennas connected by a short run of coax, one outside and up high, and the other inside and lower. WiFi may require more drastic measures to solve, but would also have no monthly fee if I can get it to work with the airport's setup. I've tested the cell antenna design already, however I still need to play with a WiFi method using some kind of active repeater with an external antenna. Hangars make great Faraday cages, but really suck when you want signal inside.

I've been looking into these as well. I found some Chinese rigs on ebay that run about $100, plus whatever the sim card costs. Reiff also has a rig that's probably more likely to work, but is more expensive...both for the unit and the sim card.

All the sim card powered units are designed to be triggered from a cell phone, which is useless to me. I've been unable to determine whether a landline phone will work properly with them and don't really want to spend the money to find out.

Wifi powered switches are supposedly super-easy, if you have wifi at your hangar. I don't.

Regarding leaving the heat on all the time...the consensus is that you can do that safely IF you have cylinder head heaters, but NOT if you just have an oil sump heater. The oil sump heater just vaporizes the moisture in the oil, which then condenses on all the cold metal above it, which is exactly what you don't want. If that's true, then pre-heating and not flying is a super-bad idea if all you have is a oil heater, as you're essentially doing the same thing.

With a cowl cover, cylinder head heaters and the oil dipstick removed, the moisture evaporates out of the engine. Or so the makers of cylinder head heaters claim.

I agree with others that leaving a airplane plugged in 24/7 is a ridiculous waste of energy if you're not flying several times a week, or if your aircraft isn't used in emergency services where the switch failing to trigger is a much bigger deal than for a pleasure craft.

After pondering the alternatives for a while I just gave up. I don't currently NEED to fly anywhere, and I'm just not convinced any of the remote switch solutions will actually work.

Last winter Spruce had a $50-off rebate on the SwitchBox http://switchboxcontrol.com/all-products/switchbox. I had been making the 40-minute drive each way to the hangar to plug in the plane prior to flying, so being able to send a text message to accomplish the same was a real upgrade. SwitchBox is a bit more $$ than home-grown solutions, but it is well engineered. The app it runs on responds with a success message when your instruction goes through, so you know you're good to go.

Thanks guys!

Hammer, my situation is similar. Hangar is 30+ minutes away and definitely no wifi available. I don't think I can get a 'hotspot' thingy either (not a techie) since I use a Net-10 phone and I think they specifically state no hot spot thing. AT&T and Sprint are the major cell carriers up here, not sure if T-mobile would be a workable option.

I actually found the Switchbox website after I posted the earlier comment. Might be the best option and I suppose it isn't too overly expensive, but funds are a bit tight right now.

I did find an article in the April edition of Sport Aviation on how to build one. I may try to just build one. About half the price and I can buy it piecemeal. The author states around $160 in parts.

Ya, if I wanted to spend an extra $200 a month I could get a cell plan and put a hotspot at the airport, but it ain't worth it to me.

I think the sim-card based systems are probably pretty good, providing you can trigger them with a cell phone...i.e., you have cell service at your house. Lots of options out there, and many of them have external magnetic antennas so it's simple to get the signal into the hangar. $30~50 on ebay.

In researching sim cards I found that most of the devices will only work with a "pay as you go" card...not sure why. I guess some game cameras use the same technology, so a good cell shop should be able to give informative advice.

good luck

Hammer wrote:Ya, if I wanted to spend an extra $200 a month I could get a cell plan and put a hotspot at the airport, but it ain't worth it to me.

I was finding hotspot plans as low as $15 a month, you just have to buy the hotspot.

colopilot wrote:

Hammer wrote:Ya, if I wanted to spend an extra $200 a month I could get a cell plan and put a hotspot at the airport, but it ain't worth it to me.

I was finding hotspot plans as low as $15 a month, you just have to buy the hotspot.

No...you have to buy the hotspot, and a phone, and a phone plan...none of which I have.

Hammer wrote:

colopilot wrote:

Hammer wrote:Ya, if I wanted to spend an extra $200 a month I could get a cell plan and put a hotspot at the airport, but it ain't worth it to me.

I was finding hotspot plans as low as $15 a month, you just have to buy the hotspot.

No...you have to buy the hotspot, and a phone, and a phone plan...none of which I have.

There are standalone hotspot plans. It's cheaper to add on to an existing plan of course, but I noted a few that would work by themselves and weren't unreasonable.

In any event,= I'm sure you will sort this out, just pointing out you don't need to buy the cow to get the milk here.

Here's a video from Switch Box Control that covers their smart phone app, the way the device works, what it takes to activate the switches, and the costs involved. It's quite inexpensive to operate. At its most expensive, it's $0.20US per operation, but can cost nothing in some use cases.



As long as there's cell coverage in the area, you should be just fine.

FWIW, Reiff no longer sells a remote switcher--too much trouble with them. You'll see that on their website, and I talked with Mr. Reiff at OSH about it. Although they specifically sold it without any warranty, he got too much guff from customers when they failed. I had one, and it fried itself the second season, although I was using it well within its advertised wattage limits.

I contacted SwitchBox, and it sounds like it will be a good replacement. I haven't ordered one yet--so far the winter has been pretty mild, although the nights have been cold, so on those days when I plan on an early departure, I've just plugged the airplane in at my convenience a day or two early.

While my old one was working, it was pretty handy. My hangar is 32 miles and 54 minutes from my home, so it's generally inconvenient to just "drop over" to plug things in the night before.

Cary

Can be done a lot cheaper.

Have a look here https://www.banggood.com/RTU5024-GSM-Ga ... rehouse=CN

This works for me.

soaringhiggy wrote:Can be done a lot cheaper.

Have a look here https://www.banggood.com/RTU5024-GSM-Ga ... rehouse=CN

This works for me.

So are you using that? How long and how much draw...I've heard of a lot of failure from the inexpensive alternatives, but if that works it'd be great.

Here's what I used for a few years:

http://www.apogeekits.com/remote_contro ... _phone.htm

It's a kit that cost about $20. Basically it triggers a relay when the light on the cell phone comes on and the relay switches on/off your heater. I'm sure you could rig something using a landline that lights up as well. I used a cheap throwaway cellphone when I was using it. Uses zero minutes because you never answer the phone.

Seems like a good idea. But don’t those random nuisance calls trigger it?