Electric space heaters

rhagfo wrote:

wa8yxm wrote:
The problem is not the heater. most of them are safe now days (I like to avoid the ones that glow red however) Ceramics tend to be very compact. Oil filled very large. But all of them give exactly the same amount of heat for the same amount of electricity. all heaters are 100% efficient so if the maker says something like "3 times more efficient" they are lying. (The reason is in an electrical system all losses express as heat, with a heater this is the desired output so all losses are recovered).

Page 2: The Danger
Quick box or Unibox outlets use punch down connectors that are great at say 100mA or less (telephone current) but not so good when the amps hit double digits.

A 1500 watt heater is 12.5 amps I had one outlet overheat I've seen them melted down and wires broken and acing. Serious fire hazard AND I AM NOT AN RV SERVICE TECHINICIAN just what I've seen

I used assorted electric heaters. mostly hot (but not red) wire, some ceramic. for 15 years. But I also installed special circuits (3 of them) two were dedicatred circuit breaker via 12ga wire to a 15/20 amp duplex outlet (has a "T" shaped neutral slot) the third was 12-ga from a dedicated breaker to a GFCI (Kitchen 2) with a 2nd standard Duplex "Daisy" off the GFCI (Also GFCI protected)

Never smelled hot wire after that.

This the biggest issue with using portable heaters in an RV! The outlets don’t have screw down terminals, the insulated wire is pressed into a blade of metal that pierces the insulation and makes contact with the wire inside, it has a small contact area. That small contact area and high draw create heat in the outlet it self.
We full time so heating is an everyday process for us in winter, my father was a firefighter and saw many fires started by portable heaters, with some deaths.
Pianotuna has installed heated carpet, which keeps feet warm, the thought is interesting to me.
We chose to heat with the RV comfort systems electric furnace add-on system, this adds an electric heating element to the furnace air path, so not only heating the interior of our 5er we heat the basement. We have a temperature sensor in the basement and at just below freezing outside it reads between 51 and 49 degrees at the outside wall.

Most RVs use a "self contained" duplex outlet as mentioned above, this type of outlet does not need any electrical workbox.

This outlet subject often brings out a lot of arguments that they ARE NEC type accepted and "safe" to use and those folks have never had an issue with them.

While I have not personally seen one of these go up in flames or overheat, I am a bit hesitant in loading this type of outlet very heavy for a prolonged period of time (as in a space heater) after actually seeing the inside guts.

So, just so folks can see what concerns me, I have taken one a part and posted it multiple times on this forum..



Contact is 24ga material which is .0239 inch thickness, wire contacts on two sides so the overall wire to outlet contact area is .0478 inchs

Wire in contact photo link


Photo of wire contact link



Compared to a regular screw terminal outlet which the contact area is 5/8" LONG (.0625") and two sides of wire contact is 1.25"..

Photo of regular outlet link



Nicked wire photo from Hubbell device


The pix do not lie, you are depending on a very small contact area for the wire and outlet device. You are depending on the springiness of the outlet material to not fail under high current draw.

Less contact are = high resistance connection.

High resistance connection = High HEAT.

High heat = soften metal.

Soften metal = less tension.

Less tension = even higher resistance.

And so on and so on.

If you are really set in your mind to use electric heaters for a long term heating solution, use them on a lower heat setting and use a couple of more heaters spread out across different outlets..

OR install a dedicated heavy duty outlet for the heating device.

Alternately is installing a couple of permanent wall type heaters and hard wire them in. You can get forced air 120V permanent wall heaters, they also sell low profile "kick space" heaters for under home kitchen cabinets or even short permanent 120V 500W baseboard heaters that do not have fans (look like a how water baseboard heater).

Camp safely!