Looking for advice on a radio controlled switch

[dylanallen]

Hello,

I have an auxiliary LPG heater in my campervan which I'd like to turn on remotely to warm it up before I get in.
It runs on a 12v supply (don't know how much current it draws but it's just a fan and a gas ignition, so probably not much) which is independent from the ignition. It's controlled by a rocker switch on the dash which I plan to bypass; having both the original switch and the radio switch wired parallel to each other.

I'd really appreciate anyone being able to recommend an appropriate product available to buy in the UK.
I saw a 1-channel radio switch at Maplin but it is the sort of thing you'd use for a garage door, so I thought it was a bit too heavy-duty (therefore bigger and more expensive than I need).
It only needs 1 channel, but if an extra channel doesn't affect the price too much, then 2 channels wouldn't do any harm (I can't think what I'd need the extra for, but I might find a use in the future ).
Range-wise, I'd like to be able to activate it from my desk while it's out in the car park, so a couple of hundred metres should do it.
I nice bonus would be some kind of feedback to let me know that it worked each time, but I don't know whether that's a whole other kettle of fish...

Thanks for taking the time to read, hope someone can help. Thanks!
-Dylan

[David]

Try Google and Amazon - various ones are readily available.

(As you are using a DC supply don't forget to use a switch with a larger current carrying capacity than you might expect. The combination of DC current feeding an inductive load (the fan) is a potential source of arcing on switch off, as the back EMF tries to sustain the current. You may not experience this depending on how your particular heater reacts. It may already incorporate some suppression components.)

[dylanallen]

Thank you!
I've seen a few now that might do the trick.
And thanks for your advice on current. I don't have any spec's for the heater but i do have a multimeter... if I just put the probes across the switch terminals and switch it on, will that give me the value that I need to know? (With the multimeter set to the right mode, obviously )
Thanks again!
-Dylan

[David]

Yes, use the mulitmeter on its highest current range to start. You may find that the fan draws several amps ...
(incidentally, putting a meter across the closed terminals of a switch will read nothing in current terms. You will need to open the switch and let the fan current pass through the meter. Take care if you are using a meter with a dial and pointer. I have seen overloaded meters bend pointers before!)

[dylanallen]

Brilliant, thank you so much!