Sometimes it is the smoke fluid.. I thought all of mine had gone until I tried a new batch of smoke fluid and they started working again.. Unfortunately, it seems, at least in a tropical climate, the smoke fluid seems to go off after a seven years.

I believe that running the smoke units without smoke fluid will decrease the life of the unit. The fluid acts as a coolant for the heating element so running it without fluid may allow the element to operate at temperatures higher than it was designed for. With continued heating and cooling cycles the material becomes brittle and eventually fails. Think about how incandescent light bulbs fail.

David

This is a good point, since you are running analog, these smoke units are being powered all the time. Mine are only on when I switch them on, so they are not always hot even when no fluid is present.

Agree with John, if the unit still fells hot, then it should work. I have a fifty year old unit that still works well in a DA 800.

Here is what Seuthe says about their steam units: (http://seuthe-dampf.de/service/?lang=en), they could use a professional translator :)
"Must be the steam generator always filled?
As long as you do not exceed the permissible operating voltage, will not be damaged in dry run of the steam generator. In the analog domain, the voltage with the control knob is determined. Since no one constant full throttle drives, is burning through the steam generator unlikely."

I'd add that the smoke unit has a warm up time in analog mode, so if you run your trains in a frequent stop/go scenario, say run for 2 meters, then stop at a signal, then go again for another 2 meters, then the performance will not be great, and you might not even get steam at all.
Most of the time, the "failures" I experience are due to a bad contact or overfilling. With overfilling, there is also a risk that fluid gets inside the loco, and accumulates on the contact for the smoke unit, this needs to be cleaned in this case.

On the 7226 units, the Seuthe 200 replacement smoke pipes have proven useful over time.

I've got a limited experience with smoke generators - a total of 1 installs - putting the 7226 (a Seuth #10) in the 37899 driven with Seuth fluid.

The issues I had were getting it to work initially, which had to do with the screwball way of aligning the contact on the bottom of the smoke generator with the copper contact inside the loco, never having taken appart the locomotive before or being able to see where the contact was. So of course I guessed wrong and didn't get contact - since you can insert it in any of 360 degrees of orientation variation. Once I got it aligned well, it worked like a charm.

The design of that #10 is like a test-tube. There isn't a way for the fluid to get out except out of the top, which would be as its inserted down the chimney, dump fluid on the outside of the locomotive.
I would expect short of me breaking the tube mechanically, that it would run forever.

That said, the installation of the smoke generator in a plastic body Roco BR 012 I should be getting in 2018 will be more concerning as its more delicate, but I'd expect it to work solidly for years to come so long as I don't get it running so hot that it melts the loco body.

Definitely leaving them on while there's no smoke fluid kills them (this applies to types that aren't designed from the factory to be always on). Also make sure you choose the right power of the unit for the application. e.g. Seuthe #10 for digital (not always on) applications to get maximum smoke. Seuthe #11 for analog/always on applications (but they wont get as hot so not as much smoke when running).

I also try and drain whatever is left in there after using it.

The other thing I've found is using the KM1 smoke fluid works so much better than any of the others. The fluid doesn't have oil in it so it also doesn't leave that nasty residue on everything. Make sure to only use in Seuthe style generators (none of the 'live' smoke models like from ESU, Roco, etc. as the pumps on those rely on the oil).

Hi!
In the past when the Seuthe site was not responsive, but was useful and had an FAQ list, they warned about operating smoke generators "dry" and a reduction of unit life time.

They wrote this normally wasn't an issue for analogue operation as no one runs their trains constantly at full speed. They should know Märklinists better.

Link to German site in the web archive (click FAQ):
https://web.archive.org/...he-dampf.de:80/start.htm

Not sure about that assertion - because Märklin disagree with that assessment.

37899 is a factory digital locomotive, that is set up for the 7226 smoke generator, which is claimed by many to be the Seuth # 10, aimed at the 10-16v range. From images I can find of the 7226 (don't remember what mine looked like) the 7226 has the red bottom, that is the #10.

The #11 for 16-22v power (green bottom) is not the one spec'ed by Märklin for the digital locomotive.

It's the effective voltage that matters.
A smoke generator wired between centre rail and outer rail gets the full track voltage and you need No 11 for digital (Delta is digital).

A smoke generator wired between decoder and outer rail gets a reduced voltage and you need No 10 for digital.

You can always try No 11 first, even for analogue operation. Install No 10 if you don't get smoke from No 11.


It's more common to wire them in parallel.