pilot goes out

[michaels]

I have an older Coleman standing pilot furnace (90-91, Natural Gas). A few weeks ago the pilot/burner assembly was replaced. The furnace has gone out 2 times now while i have been out of the home. The thermocouple was replaced w/ the burner assy. I tested the thermocouple today. 29+/- millivolts DC was my reading. The pilot flame is a soft blue but there is flashes of yellow also. Could this be a primary air issue or is a down draft causing the pilot to go out?

[Robert]

Hi,


Flame should be blue with at most a slightly yellow tip. It could be a down draft problem.


It could also be a cracked heat exchanger,


As you can see, it can be a minor to major and would need to be thoroughly tested to know for sure which it is.


Could also be a faulty thermocouple or a thermocouple not inline with pilot flame. Pilot flame should cross top 1/2" to 3/4" of thermocouple tip.




Take care and best wishes,
Robert

[michaels]

the tech. that replaced the pilot/burner assy. checked the heat exchanger and it was fine. the flame covers about 1/2 inch of the thermocouple. my exhaust stack does not extend much from the roof. should i add an extension to it if it is a down draft problem. the pilot has stayed lit since friday.

[Robert]

Hi,

Yes, an extension would likely help:


http://www.mobilehomerepair.com/ColemanChimneys.html


Also, test the thermocouple, do not assume it is ok because it is new.

In 28+ years of this, it is only component I have replaced as many as 3 times on same furnace and have done so more than once.


They can and do sometimes become defective.



Thanks,
Robert

[michaels]

i got a extension but the box said coleman 4000 series. mine says it is a 7900 series. will that still work. i am having problems putting it on as well. it does not want to slide over crown assy. base. any suggestions.

[Robert]

Hi,


Did you order it from us ?




Thanks,
Robert

[michaels]

i got it from a modular home store in our town. and they said this is for coleman and it goes to all coleman. i did get it put on but i had to push and squeeze and it finally slid over but there is a little indentation from squezing it on. i tried to pull the dent and could not. i wrapped foil tape around it to prevent anything from getting in it. do u thinh that will be ok? the extension i got is the same thing i saw on the link you sent me.

[Robert]

Not much I can help with since it was purchased elsewhere.

You'll need to contact the store where you bought it as they should stand behind the sale and advise on it.


I can tell you that 7900 is Interior Extensions and 7600 is Exterior Extensions.




Take care and best wishes,
Robert

[michaels]

The numbers on my box match the ones on the website link you sent me. The instruction sheet is even the same.

[Robert]

That link shows 4000 series roof jacks, 7600 series exterior extensions and 7900 series interior extensions.



Those are the correct numbers for those 3 items.


I do not know if you needed interior or exterior, but those are the numbers.


However, if there is a question arising after the purchase, it needs to be addressed to the store where it was purchased.


4000 series = Coleman Roof-Jacks

7600 series = Coleman Exterior roof jack extensions

7900 series = Coleman Interior roof jack extensions.




Take care and best wishes,
Robert

[michaels]

i is a exterior extension. is there a difference between a 4000 & 7600 series?

[Robert]

4000 = Roof-Jack

7600 = Exterior Extension for use with 4000 Roof-Jacks.




Thanks,
Robert