Natural Gas Fireplace model ND3630 pilot light won't stay lit

[Colorado55]

I have a Natural Gas Fireplace model ND3630 - I have replaced both the Thermopile and Thermocouple and pilot light will not get past the turning up of the burner knob on the valve to full for to long. It will light and stay lit (Blue Flame only) for a couple seconds and then click the gas valve shuts off - If I remove the glass the flame I get both blue and yellow flame like it should - in my opinion it acts like its starved of oxygen - this unit doesn't have an oxygen sensor at all

Could this be a valve problem as only thing that I have not replaced - This si a direct flu system and have checked from roof down for obstructions and do not see any - even put a chimney cleaning brush down there and did not see anything when reaching bottom.

 

[DAKSY]

Take a mV reading on the thermocouple & tell us what you get.

 

[bigealta]

I've had bad New out of the box thermocouples in the past. Used on my gas boiler. They are not as good as they used to be. Make sure it is set correctly in the pilot flame. Then i'de try another new one.

But does the pilot stay lit? if so then thermocouple is probably not your problem.

 

[DAKSY]

Also check for pilot flame agitation by the incoming air.
If the pilot flame does not hold steady on the TC, it'll shut the gas flow off.
Sometimes, just a small shield fabricated from a thin sheet of aluminum
can help mitigate this agitation...

 

[Colorado55]

I've had bad New out of the box thermocouples in the past. Used on my gas boiler. They are not as good as they used to be. Make sure it is set correctly in the pilot flame. Then i'de try another new one.

But does the pilot stay lit? if so then thermocouple is probably not your problem.

Pilot stays lit as long as i do not turn burner knob all the way up, if I do click sound and gas shuts off to valve - if I have the switch turned on for full flame

 

[Colorado55]

I've had bad New out of the box thermocouples in the past. Used on my gas boiler. They are not as good as they used to be. Make sure it is set correctly in the pilot flame. Then i'de try another new one.

But does the pilot stay lit? if so then thermocouple is probably not your problem.

Pilot light stays light if I DO NOT turn gas valve knob all the way up have to play this find out where the pilot light stays on game after pilot light setting on knob - - if I have the switch turned on for full flame

 

[Colorado55]

I've had bad New out of the box thermocouples in the past. Used on my gas boiler. They are not as good as they used to be. Make sure it is set correctly in the pilot flame. Then i'de try another new one.

But does the pilot stay lit? if so then thermocouple is probably not your problem.

 

[Colorado55]

Pilot light stays light if I DO NOT turn gas valve knob all the way up have to play this find out where the pilot light stays on game after pilot light setting on knob - - if I have the switch turned on for full flame