Majestic Gas Fireplace - Will not light

[MajDad]

I have a Majestic gas fireplace (model - UVL 18RN). I can get the pilot to light but it goes out when I set the pilot light to on. I read in a forum that the burner orifice can become clog. Can someone tell me what the burner orifice is and how can I clean it out.

thanks

[HayZee518]

your problem might not be the pilot orifice but the thermocouple that keeps the pilot valve open after you release the "light" button and turn the control to "on." a copper colored probe that sits in the pilot flame is what generates a millivolt signal is applied to the pilot valve. inside the main gas valve is a extremely sensitive electromagnet that operates off a 750 millivolt signal that is generated by the heat of the pilot flame. that, in combination with a spring either keeps the pilot valve open or closes via a spring action within the valve. the burner orifice is a brass tip with a very small hole in it - I would have to guess it is perhaps .002 or .001 inch diameter. it may just unscrew from the pilot tube.

[MajDad]

Thanks for the quick reply. Is there any way to test the thermocouple to determine if it is bad or not.

thanks

[HayZee518]

if you are handy with a multimeter set it to its lowest range and clip one lead to the copper cappilary and the other to the silver button on its end - the end that screws into the valve. then heat the tip with a match flame. if its working you should see a voltage on the meter. if the voltage is lower than 250 millivolts then the thermocouple is no good.

[boogyshoes]

cleaning the sensor

I had the exact same problem with my majestic gas stove.
Opening the stove I noticed under the underside of the stove, where the pilot flame and wiring of the sensors leaves the stove, the exit has a silicone fill to prevent exhaust gas from leaving the stove. In order to not have to take apart the silicone, I simply used a dremel tool with a wire-brush cleaner and cleaned the carbon off of the sensor. I re-assembled the stove and tested the pilot flame. I attached alligator clips to the probe connectors on the control unit that leads to the temp sensor. Before cleaning, I was only able to read 0.160V, after cleaning it read 0.450V and now the pilot would stay on without going off. Thanks for the advice.

[LarryHome]

If the pilot stays lit it could be a couple of things. Check the milivolts on the thermopile to make sure that its still good. If that checks out then jump the th/thtp screws on the valve and see if that turns it on. If that doesnt work make sure the valve is in the on position and not the pilot position. If none of that works call your dealer.

[LoriBuckeye]

How do you clean the thermopile? Any advice would be appreciated.

[HayZee518]

check up two postings - i.e. dremel tool with a wire cup brush