problems with coleman evcon

smartin1971 · Mon Nov 16, 2009 8:49 am

this furnace # DGAT095ADC
my furnace has very short run cycles..will run for awhile and shut off....then 30 sec. later it comes back on..have a new T-stat and changed filters and made sure all flu pipes were clear.do you othink it could be the fan limit switch? thanks

scott martin

smartin1971 · Tue Nov 17, 2009 10:37 am

still havnt heard from you guys.?

Robert · Wed Nov 18, 2009 1:43 am

Hi ,

Could be several things. Limits, main burner orifice clogged, heat chamber clogged/dirty, heat anticipator wrong setting, short in wiring circuit.

Are the burner and blower cycling or just one of those ?

Thanks,
Robert

smartin1971 · Wed Nov 18, 2009 5:00 am

the blower only comes back on (and this happens almost as soon as the furnace shuts down)also when the furnace does shut off.the fan seems to run a bit ,but when i tap on the furnace it shuts off.??

Robert · Wed Nov 18, 2009 5:32 am

Hi,

The blower is controlled by a fan switch. It could be faulty and weak and opening/closing intermittently.

Fan Switch # 7975-3281 can be seen and ordered through PayPal from left side of this page:

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

Could also be something dirty or clogged up in airflow pathway not allowing the heat to fully disperse and residual heat raising temp back to cut in temp of blower.

IF replacing fan switch and ensuring all is clean and clear doesn't resolve the issue, may need to change the fan switch to a F120-30 to give an extra 10* difference in cut in and cut out.

That may be enough to eleviate the problem without giving up any safety features of fan switch.

It would heat up to 120* instead of 110* before blower came on and cut out at same temp of 90*.

This would give 30* difference as opposed to 20*.

Would need to call Mark toll free at 1-877-263-7860 to get him to see if he had a F120-30 fan switch or could get one.

Thanks,
Robert

smartin1971 · Wed Nov 18, 2009 12:49 pm

okay.i will order that switch and awap that out ..also i noticed that the upper limit swith (with the manual reset button) is all corrodid and stuck..do you recomend i change that out as well.? thank you for all you help..

Robert · Wed Nov 18, 2009 2:22 pm

Hi,

Yes, should replace it also.

Upper Limit # 7624A3591 from left side of same page from above link.

Thanks,
Robert
www.mobilehomerepair.com

smartin1971 · Thu Nov 19, 2009 6:59 am

okay. i have ordered the parts.. i will let you know how it goes once they arrive and i install them..
again..thanks for your help

Robert · Thu Nov 19, 2009 5:56 pm

Hi,

You're very welcome, happy to help.

Thanks,
Robert

smartin1971 · Mon Nov 23, 2009 7:57 am

that seemed to do the trick..thanks again for your help...

scott martin..

Robert · Mon Nov 23, 2009 8:14 pm

Hi Scott,

Glad to do it and happy it resolved the issue.

Take care and best wishes,
Robert

smartin1971 · Sun Dec 06, 2009 5:12 am

hey Robert
seem to have another problem..the furnace will start up and the glow plug will come on..but the furnace will not fire..blowing nothing but cold air..any ideas..please hekp..thanks

smartin1971 · Sun Dec 06, 2009 8:50 am

my furnace has fired now..seems to be an intermintent problem..still would like to know what you think...also the glow pug stays on while the furnace is running...is this correct..thanks again

Robert · Mon Dec 07, 2009 1:37 am

Hi,

Would need to check burner orifice and gas valve pressures.

Glow plug should stay energized about 30 seconds or so.

Thanks,
Robert

smartin1971 · Mon Dec 07, 2009 5:10 am

okay,,when the furnace kicks on the glow plug lights..there is a delay then i hear the click for the gas valve.? yesterday it wouldnt fire after the click..it seems when i tap on the gas valve it fires.? also if the glow plug stays energized for to long what can that mean.? by checking the burner orifice im looking for a clog of some sort.? thanks again and sorry for so many questions..