14.5" stops flowing when fully hot

[David Chesler]

 While I was despairing about my 8100's broken glass, I bought a 14.5" model 2121 (pink/purple, 20 oz.) at Walmart (and now they've rolled the price back another $4 to $12.88). I didn't change anything, so it's running with its OEM 25 watt intermediate bulb.
After a little warm-up it flows nicely, but after a couple of hours or so it just sits there with all the wax on the bottom, somewhat bulged up.
 What's up? How can I fix it?
 (About the only user-modifiable part is the bulb. Even though I am now an expert  in balancing distilled water, salt, and surfactant, this model has a crimped-on cap. I've run it through about a dozen duty cycles and this behavior is consistent.)

[Keith]

One of the reasons many of us here don't like globes smaller than 32 oz.  They can overheat easily.  Since you say it does flow nicely before it overheats I would suggest using an inline dimmer to control it.  Dialing down the current just a small amount may do the trick.  Also consider ambient room temp.  Anything over 75F can cause problems, depending on the lamp.  I have one that stops flowing from overheating if the room is above 72F, and it's a 52 oz Century.

Does Walmart have a 30 day price guarantee?  You might be able to recoup the $4 if so.

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