Furnace shuts down after a few cycles

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What would I need to do in order to completely disconnect the 2 flex tubes from the furnace system?

pvplyr

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Disconnect them both. Then permanently seal up the return air opening in LR floor and seal the opening in the main trunkline IF he had connected to it.

You can get sheetmetal or aluminum flashing and bend it over the opening, shoot some sheetmetal screws in the edges. tape the edges with foil backed duct tape.

Then cover entire patch with Mastic Duct Sealant (get it at HVAC Supply or big home centers maybe).

Turn power OFF, disconnect electrical and remove the unit if you wish.

Take care and best wishes,
Robert

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Thanks for the info. I doubt it will help the burners staying lit but at least I won't be heating the outdoors anymore.

pvplyr

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I have the same exact problems with my Coleman dgat070
you described my furnace like you owned it.

Anyway I found my problem was with the lower limit switch
it would shut the gas valve off at the same time the fan kicked on and after 3 tries it went in to safe mode and at first I was just getting a failed ignition code and after a week of fighting it and taking the burner out and completely cleaning the combustion chamber and chimney I got a 4 flash code (limit switch)so I found each limit switch and bypassed them 1 at a time until the furnace ran normally and it was the lower limit acting up was 11.00 plus shipping from this site.

simidrm

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I've been checking on the net about limit switches and flame roll out switches and have a couple questions. 1.My flame coming out of the burner is as blue as it should be but what I see is after the flame hits the deflecting plate in front of it, the flame bounces all around the chamber and turns more orangish. Is that normal? 2.Could this backlash of flame be hitting the roll out switch and shutting the burners down? 3. would too much LP pressure cause this much flame to be present? 4. Why would it appear the flame is dying a little out of the burner just before the burners shut down? Thanks for bearing with me on these issues. I am just trying to get by with the chepest things first this close to Christmas. Single income family and all.

pvplyr

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Number 1 is no
Number 2 is possible
Number 3 is yes
Number 4 is the gas valve is possibly closing shutting the gas off.
When was the last time someone really checked your heat exchanger. There could be a problem with a crack causing Number 1 and 2.

hvac1000

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Hi,

It really needs a thorough inspection by someone experienced in this type unit.

A faulty Hot Surface Ignitor will cause this, a faulty Remote Sensor will cause this, a faulty Ignition Module will cause this.

Irregular or insufficient combustion air will cause this.

The erratic flame can cause the GV to shut down.

The flame should not be orange/yellow and this can be to dangerous situation and can lead to shut down.

If it can't be detected while there, the Tech needs to leave test equipment connected to show where the fault is while he isn't present.

With the erratic flame and orange/yellow coloration, it is imperative to have it inspected by a competant Tech.

Too dangerous not to.

Keeping safe is the formost importance here.

Take care and best wishes,
Robert

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Good news. After about a week or so of nice weather, my repairman stopped out to take another look before the cold snap. It finally messed up in front of him and what he found was as simple as a partially blocked flue system. The last time I cleaned it,I just did the tubing from the top of furnace to the roof jack. There was a lot of blockage in the bend going over the blower fan. It ran all night with no problem. We'll keep an eye on it but so far so good. He only charged me the one service call of $55. Thanx for all your help.

pvplyr

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So how did he clean the part of the flue with the bend,as I tried this once with compressed air and my wife was ready to kill me after all the soot covered everything in the back half of the house.

simidrm

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He took apart the flue going into the roof jack and cleaned that. That was easy to get to. Then all he could do was hit the rest of the bending flue system with a rubber mallet. After hearing all of the blockage falling, he then swept out the combustion chamber with a shop vac. he got most of it but of course some residual did burn off when it cycled through. It wasn't that bad though. Just smelled like it would when the furnace is lit for the first time of the season due to some dust settling on the heat exchnger or something. We're going on the 3rd day now and it's still runnin like a top. Happy holidays to all!

pvplyr