Before I ordered mine, I had read somewhere that the smoke units had issues; but, I took a shot anyway.
It took 2 calls to customer service first.
On the first call, the rep asked me to see the Lionel video 'Smoke Refill 101'. I did and followed that video's suggestions. Still no smoke.
On the 2nd call, another rep gave me an RA number and sent me an RA email.
You have to return the loco, tender, remote, a copy of your sales receipt for warranty service, a letter stating the problem, and include your return address, the RA number, and print the RA number on the sides of the shipping box.
I had to pay shipping there.
The Trainworld outer box that I sent it in was on its last legs; so Lionel sent it back in a new outer box - nice touch.
The Lionel tech did no damage to the loco - just as pristine as when I sent it.
RickM46