Sorry for the repost. First post doesn't show up.
After much trial and error, I found a ceramic space heater that seemed to smell least like burning rubber or plastic. I purchased two. They worked for one winter. This winter, I repeatedly smell an ongoing machine oil smell coming after about half hour operation. The colder the intake air, the more it smells like the oil is burning; this is only a rough correlation, it isn't *always* like that. So when the air is cool, it will often smell like hot oil; when it is cooler, it smells like smoldering oil, or even burning oil (at this point, it smells like a diesel engine, or burning rubber). The diesel smell sometimes occurs even when it is warm. More ofthen, though, the smells are less when the room is warm (above 75F), but I don't really need them that much when the room is warm. Unfortunately, I occupy a space which must be continuously ventilated with outside air, so it's always cold (which is more likely to bring on the problem with the oil smell). The only guess I have for the cause of the problem is that cold temperature affects the seals for the motor lubricants. The lubricants leak out and get heated or vaporized by the heater. This is only a guess.
After prolonged continuous exposure to the fumes, it can be quite nasty. The machines still have plenty of warranty time left, but I doubt the store will take them back (and that's reasonable, considering that I used them throughout last winter). They need to be sent to the manufacturer; I imagine that round-trip shipping will cost in the order of half of the original price of the machine. I also need a heater at all times. Even if I sent it, the manufacturer would probably replace them with a newer model, but there is no guarantee that the problem will be eliminated; as I said, these were least smelly of many heaters tried, and it is possible that new ones will smell worse at the outset, (and maybe even more worser after one winter). Hence, sending it back does not seem like a good option.
For the sake of breathability, I am considering getting 2 more heaters
-- without any fan motors. This leaves oil-filled and radiant heaters (with the orange glowing tubes). Because of the continous draft from ventilating, I think the radiant heaters would be most suitable. However, the only radiant 1500W heater I've seen has a fan at the top. The ostensible reason is to distribute the heat more; of course, it does this, but I suspect the real reason because the machine simply gets too hot. People buy radiant heaters because they want focused heat, and the improved distribution from the fan would not be appreciated in those situations.
I've looked around quite a bit to find a 1500W radiant heater with no fan (found some 1000W ones). They don't seem to exist. Is this a pointless search? I am searching in Canada.
I'd also appreciate any comments on what might be causing the smell. Is my guess at the temperature dependent lubricant seal plausible or likely? Does my reasoning for not sending it back seem sound? Anything I've overlooked?
What about my rationale for choosing radiant heaters over oil-filled for my situation? Perhaps someone from outside my situation can see some considerations that I currently do not.
Thank you.