gas fireplace going on & off -- help!

[floatee]

I bougtht a Jotul gas fireplace (used, uhhhh) and have run into a problem trying to get it running properly. It'll fire up just fine but after about 20 minutes it abruptly turns itself off. What I mean is, the pilot lite remains lit but the fire itself turns off. And then a while later, it'll go back on again, and so forth. Any ideas about what might be causing this? A bad thermopile? I've removed the remote control and tightened all the connections and that hasn't helped. I've hooked a multimeter up to it and get about 460 millivolts with just the pilot light, just shy i think of the 500 mv that i understand is considered ideal. with the flame on, it starts out at around 230 mv and over time drops down to about 180 mv and then comes up again and goes down again and maybe for a while even hovers in the 230 mv area. does this suggest anything? thanks!

[yourname]

does it have a thermostat? My [not jotul] will supposedly do the same to try to keep the room at a certain temp

[SQLit]

Google is your friend, assuming of course that you do not have/read the manual.

[floatee]

nope, it doesn't have a thermostat. i've googled quite a bit on the problem and haven't really seen it come up. most people have problems with the pilot lite, not with the flame itself. my pilot lite works fine or at least is continuously on. the flame is the problem.

thoughts, anyone?

[Bob]

Check your high limit switch.

[floatee]

i don't think it's got a high-limit switch. it's got a variable low to high flame knob but that's about it, except for the on-off switch and the pilot flame adjustment screw.

other thoughts?

[Bob]

I'm not familiar with that unit, but just about every other unit I've seen has a high limit. Do you have a schematic?

[SQLit]

They have pdf files for down load.

Like you said it was used.

[floatee]

i don't have a schematic but the instruction manual makes no reference to a "high limit," or anything similar. might it go by another name?

[Bob]

Most of them are called 'high limit' switches, but I guess it could be called anything. A lot of them look like shiny little round discs and have two wires connected to them. It would normally have to be in a place that senses heat. Can you follow the wires?

[Tony Hwang]

Hi, Does it have interlock switch on the front glass panel? This interlock switch prevents gas fire if the panel is removed for cleaning, etc. My basement FP did that and the interlock switch was intermittent caused by heat. It'd open up by heat and thinking panel is removed, the fire will go off. Another suspect could be high temp limit switch(sensor) acting up. Tony

[Tony Hwang]

Hi, The switch is an enclose sensor lookiing like a transistor mounted on the side wall. Tony

[Tony Hwang]

Hi, That is safety requirement. Should have one. Tony

[CDET 14]

Could there be debris inside the gas pipe extention?

[bobblespin]

We thought we had a ghost when our new fireplace did this. Two technicians were stumped. The third guy figured it out right away: the wiring was too weak and it was turning the fireplace off because it believed it was too hot. He replace the wire that goes from the handy on/off switch down into the bowels of the fireplace with a really thick one, and it has worked fine ever since. (I forget what brand it was but it wasn't yours.)