parlor heater problems
 

i have a COZY natural gas vented parlor heater model VC351A-R, for a few months the pilot
has been going out so i figured i'd change the thermocouple, after changing it the pilot
stayed lit and i was able to turn it on for about 20 minutes after which the pilot went out
again, this happened three or four times-the flame was pretty strong and steady. now
though, i get the pilot lit then turn on the heater but the pilot goes out within one
minute. the flame goes out instantly not slowly, one second it's on the next it's off. the
unit is only 6 years old and about two feet tall by three feet long. anybody out there know
what's going on?

You may have a tripped thermal overload device.

Some pilots are designed to go out when the room does not have enough oxygen for proper combustion. The flame will "lift" off of the pilot burner in a low oxygen situation, so there is a big gap between the pilot burner and actual flame. The thermocouple is positioned so when this happens, it cools and shuts off the gas.

This is common (and required) on units that are unvented because enough exhaust in the room (low oxygen) will cause carbon monoxide to form, but I am not sure if they are used on vented units. It will probably point this out somewhere on the unit or in the instructions.

If your heater has this, make sure there is enough air in the room and that the vent is not blocked.

http://www.ventfree.org/ODS.HTM

parlor heater problems
 

i have an older gas on gas unit connected to the same vent and that has not given me any problems so it seems to me the vent is ok.