One reason not to plug a 1500 watt heater into a standard SCD RV receptacle is that the factories don't always install them correctly and according to code. The factories don't have licensed electricians and the work is never inspected by a gov't inspector like it is in buildings. A photo below is what I found in one of our TTs and only 1/2 of the hot wires were pushed onto the "stabs" and the prong was bent to the side plus the paper wasn't removed off the ground wire. Have found this in two brands of TTs we've owned. One of the RV recepts. should be able to carry 15 amps continuously but I would not trust that they were installed correctly. And if you have a few of them on a circuit and are plugging into the last one on a run, you could have a few "problem" recept's in series, compounding things. You can't install a regular residential recept. on an outside wall though so can only replace an existing one on an inside wall or cabinetry. I've found way too many various electrical issues to never trust factory work...
Using a strip heater or the furnace with add-on electric heat is noisy and not the ideal solutions in my mind. I don't like the Cheapheat system as it's a waste of time & money and they use false and/or misleading statements IMO (but will not comment further here). A plug-in portable heater(s) is a good solution, such as a ceramic cube or oil-filled heater but these provide localized heat only and can leave another area/room uncomfortably cold. If you have an enclosed underbelly and use a plug-in heater, strip heater or even Cheapheat and not use the furnace, the floor can end up uncomfortably cold. Not much you can do except maybe wear shoes or thick socks.
If going to electric heat, if you have 30 amps, the most you can use is 1500 or maybe 2,000 watts total, or even say 2250 at the extreme to have enough room for other loads. You'll have to manually switch the heater"s) off when you want to run a coffee maker, toaster and/or hair dryer at the same time. Most TTs are not particularly well insulated, esp. in ceilings if you were to take a look up there and as a result. Electric heaters can end up running non-stop unlike in a house where heaters cycle on & off and cords can get warm/hot and same with recepts.
The ultimate solution IMO is to install some recessed fan-forced electric heaters and use wall-mounted thermostats. In our first TT (a small 20 footer) I installed a ceiling semi-recessed heater in pic below. In our current TT I installed a kickspace heater under the stove and a recessed heater in the bathroom and one in the bedroom, totalling 2,000 watts and each room/area has it's own t'stat. The problem with installing permanent heaters in an RV is finding a suitable location that provides all the required min. safety clearances. If you use a fan-forced recessed heater, you want one that has a squirrel cage blower and not a propeller blade type which are a lot noisier. The ones I used are very quiet and don't interfere with the TV. I ran all wiring 100% concealed via the ceiling, walls and cabinetry. I made my own demand controller so that when the total load gets to 30 amps, the electric heat is automatically disconnected until the total load is down again. We almost never use the furnace except early or late season when the temps are close freezing. Our TT is comfortably warm and evenly heated from front to rear. An installation like this is not for the average DIY-er tho.
If you think upgrading to 50 amps will give you more total wattage, be aware that finding a 50 amp pedestal in a CG can be difficult. Prior to the 2005 NEC code edition, only 5% of CGs had to have 50 amps and then they increased it to 20%. The majority of CGs are older and unless you can find a CG (or maybe a casino) that has voluntarily built above min. code, you will need to be able to run on 30 amps.
Using a strip heater or the furnace with add-on electric heat is noisy and not the ideal solutions in my mind. I don't like the Cheapheat system as it's a waste of time & money and they use false and/or misleading statements IMO (but will not comment further here). A plug-in portable heater(s) is a good solution, such as a ceramic cube or oil-filled heater but these provide localized heat only and can leave another area/room uncomfortably cold. If you have an enclosed underbelly and use a plug-in heater, strip heater or even Cheapheat and not use the furnace, the floor can end up uncomfortably cold. Not much you can do except maybe wear shoes or thick socks.
If going to electric heat, if you have 30 amps, the most you can use is 1500 or maybe 2,000 watts total, or even say 2250 at the extreme to have enough room for other loads. You'll have to manually switch the heater"s) off when you want to run a coffee maker, toaster and/or hair dryer at the same time. Most TTs are not particularly well insulated, esp. in ceilings if you were to take a look up there and as a result. Electric heaters can end up running non-stop unlike in a house where heaters cycle on & off and cords can get warm/hot and same with recepts.
The ultimate solution IMO is to install some recessed fan-forced electric heaters and use wall-mounted thermostats. In our first TT (a small 20 footer) I installed a ceiling semi-recessed heater in pic below. In our current TT I installed a kickspace heater under the stove and a recessed heater in the bathroom and one in the bedroom, totalling 2,000 watts and each room/area has it's own t'stat. The problem with installing permanent heaters in an RV is finding a suitable location that provides all the required min. safety clearances. If you use a fan-forced recessed heater, you want one that has a squirrel cage blower and not a propeller blade type which are a lot noisier. The ones I used are very quiet and don't interfere with the TV. I ran all wiring 100% concealed via the ceiling, walls and cabinetry. I made my own demand controller so that when the total load gets to 30 amps, the electric heat is automatically disconnected until the total load is down again. We almost never use the furnace except early or late season when the temps are close freezing. Our TT is comfortably warm and evenly heated from front to rear. An installation like this is not for the average DIY-er tho.
If you think upgrading to 50 amps will give you more total wattage, be aware that finding a 50 amp pedestal in a CG can be difficult. Prior to the 2005 NEC code edition, only 5% of CGs had to have 50 amps and then they increased it to 20%. The majority of CGs are older and unless you can find a CG (or maybe a casino) that has voluntarily built above min. code, you will need to be able to run on 30 amps.
