Majestic Gas Fireplace

Hi all I have a free standing majestic gas fireplace that has a sit 630 gas valve. My problem is that the pilot light comes on and after a min when I turn knob to gas on it goes out. Ive tested my thermoscouple with a millivolt meter and I get about 28mv with a lighter on the thermocouple tip, its also clean and directly in flame. I think that my magnet solenoid isnt holding therefore it shuts off gas. No real way of testing it either just with meter in end and to body I get .2 ohms...Just wondering if anyone knows how to test it. Any help would be great thanks

I think that I may have found the problem...if I use a propane torch and heat the thermocouple and have it connected to the magnet valve solenoid whatever they call it and I hold the end of the spring loaded button in it seals in an holds until I take torch off. As it cools the valve drops out,so I reconnected my gas valve and tried it and it worked ok but after a few secs it went out. So I guess that the thermocouple is weak and doesnt hold the valve in unless theres a lot of heat there,like from the torch which got it cherry red. I tried cleaning it again with abrasive pad,fine sandpaper and now it doesnt work, and sometimes it does...So seems its the thermocouple.....

Well I tried another trick I lit pilot and held my propane torch on the thermocouple a few secs and then let go of gas valve knob and fireplace lit up and is currently on at the moment. So to me it seems still like the thermocouples the culprit/bandit. Now the dliemma finding a replacement thermocouple since mine has 2 connectors on it for a cutout....Ive checked ebay and its 95US plus 25US shipping holly cow...from Australia..Wondering if I could get one without the cutout...

Sorry connectors, I mean flat spade electrical connectors and the cutout is a thermal disc that will open upon too high heat its a safety ...Go figure I left pilot on all night and its still going this morning when I got home from work. I turned on stove and away she went was working ok ran it for about 10 mins and ok? Oh well sounds like I still need to change out the thernocouple....thanks

Hi the wiring is fine besides i jumpered the switch out, right @ thermocouple connections. Go figure its been on now for a few days only way to check it is to shut it off wait until it cools down then try it again. But that again wont solve my dilemma,since i beleive that once it cools down it wont work but who knows going to try it and see what happens

Well the battle continues I was watching last night after I managed to get pilot on, the main burner came on and it pulled the pilot flame away to just the edge of thermocouple tip and within a few secs out it went. So Im not sure if thats the draw from vent or if theres a pilot problem,I tried to adjust the pilot screw but it didnt seem to make much difference. There aparrently is a pilot injector ring underneath mounting plate so I might remove the assembly and clean it..

Thanks for the replies I havent been too worried about it now as its hot out but the last time I checked it the pilot is still lit. Its a b vent free standing majestic fireplace

Like I said before thanks again for all help....only problem is the rating plate is missing not sure where I put it and Ive moved a few times so who knows where its at.. The only numbers Ive got are from sit valve...thanks again

Well thanks for everyones input on this issue but I think ive found my answer although Im still monitoring it. I removed the log in place thats over the pilot and there is a small metal tab by the pilot it has 2 small holes in it well one of the holes was plugged a bit. I think that the metal tabs purpose is to help control the flame and keep it steady...Once i cleaned that small hole its been working great...I havent shut off gas ,and try to relight the pilot to see wether it holds or goes out other than the first time...Now this has been maybe a few months...I will keep and eye on it and see what happens....

Well Ive been running the fireplace all winter long and I decided to change a pipe connection and I moved the stove a bit and now my issue has come back. But I think its worse now as before I could heat the themocouple with a torch and the firplace would stay lit and work now it wont. Im going to disconnect the thremocouple and put a meter on it to see what kind of millivots are coming out of it so its looking like I need a new thermo couple now...will see what results I get and post back.......

Update I pulled the gas valve right out and checked everything. I pulled out the small solenoid that holds gas valve open when its working. I figured to prove wether its working or not I would connect the thermocouple as it would be in the valve but externally. I did so and heated the thermocouple with a lighter as I was holding the spring loaded solenoid to simulate the knob holding it in. After a minute I let it go and it was holding in so it was working. I had long ago tried to connect a remote controlled box that has a remote control to operate the fireplace from another fireplace I had but it was a different type of gas valve so it didnt work so I had to splice my thermocouple wires since mine has 2 external wires that go to the safety switch aka spill switch. So I think that my butt splice connector wasnt properly crimped, as it did look good, so I redid it as it must have been creating a open which therfore was causing my gas valve not to work which had me thinking bad thermocouple. I did try putting a jumper across terminals but it didnt seem to work anyhow its now working fireplace been running solid all day .....again though Ill keep and eyeon it....