DGAT070BDD quit working

[Dantheswim]

Our natural gas furnace has been running ok so far this season until the other day(besides the very annoying constant short cycles--the burner stays lit but the fan will run for 10 or 20 seconds, then cut off...back on...off... then eventually stay on to heat the house).

The whole unit now does nothing. The green status light won't even come on. The unit has power and I can hear a faint hum coming from it but won't do anything. It doesn't look like the pilot is lit either. I checked the 3 amp fuse and it is OK but I don't really know what else I can look at to solve the problem.

Also, we had an HVAC tech out a few months ago and he ordered a new blower motor for the unit but after some unexpected bills I had to install the motor myself. It went fine and, like I said, the unit WAS working fine. However, the motor I took out was a 3 speed motor and the motor they ordered for us is only a single speed motor. We do have A/C and I can't help but think we got the wrong motor. The motor on there now is part 7966-311P, is that the correct replacement?

Thanks a lot for any help. We recently bought this home and are trying to get everything fixed up and moved in, this website is a great resource!!

[Troy]

mine had the same symptoms and it was a upper limit switch. If the furnace overheats it cuts everything off. I bet that this is your problem.

There is an upper limit

switch to the left side top of furnace just under the edge.

[Troy]

I forgot to tell you, look for a round black switch with a red button in the center. I just ordered a new one from this site as mine is taped together. Looks like the button they put in turkeys, just push in the red button in the center and furnace will come back on.

[Dantheswim]

I put in a new upper limit switch about two weeks ago and I have pushed the button on it, still no change. :-/

[Troy]

maybe you should take a look at this:

http://www.dgatprogram.com/index.asp

[Troy]

check the power on the transformer? see picture below to locate line and load side.

http://www.mobilehomerepair.com/article ... .htm#short

[Robert]

Hi,

That is the correct motor, BUT you can go with a 2, 3 or 4 speed motor which is better. Since you had a 3 speed motor that had already been done and should have been replaced with another 3 speed motor.


One speed motor may be having too high of a speed for the heating and cooling down furnace too quickly.


The recall problems may also be at fault.


Need 120vac on primary-line side of transformer and 24 to 28vac on secondary-load side.


Thanks,
Robert

[Dantheswim]

Thanks for the replies! I ended up calling a tech to come out and take a look. Apparently there are two 3 amp fuses..I thought there was just the one and didn't check the other.. so a $1 fuse ended up costing me $66 but oh well, gotta have heat!

[Robert]

Thanks for update, those things happen sometimes.


Take care and best wishes,
Robert