I am looking for some trouble shooting ideas for my hvac at home.

any help would be appreciated.

 

list some problems I know a few things about them

 

thank you !



2 yr old goodman split unit.

has heating coils (dont ask)

breaker is fine

t stat is digital
have moved all switches to heat, a/c, and fan..nothing works.

removed stat face and cleaned dust from electronics board.

replaced batetries.

still no workie.


will check fuses in the mornin at the air handler and condensor....


it did this a month ago. I removed the stat face and moved the switches on the back of the board and used compressed air to get the dust out of the unit.

then it worked.

Im thinkin stat...


any ideas?





I wouldnt mind, but my kids are here and the mornings around my house have been down to 7*F at 8AM!! yes 7* in PHOENIX!!!!

 

if you're able, you need to check the the 220v to 110v transformer to make sure there's power on the load side. It could be as simple as installing a new transformer. It's going to be in the air handler with the circuit board somewhere. There's also a fuse on the circuit board that you can check.

 

If the Stat was your problem before go buy a new one, if that's not it take it back

 

climbed into the attic..well ok, i walked in the attic
checked the air handler fuses and 1 side is shot.

50amp frnr cartridge fuses...not sure if i have a spare in the garage or not...


so now, the question is, WHY DID IT BLOW???

2 yr old goodman split unit..shouldnt have any problems...unless the heater coil is too big for it...




now that Im thinkin about it ,the a/c guy never did have a line installed for the air handler seperate from the condensor...maybe I am hittin to high of load on heat....hmmmm something to check in the day light....









I could ram-rod a piece of #6 solid cu in place of the fuse*



*do not attempt this.. I am only kidding ...

 

the electrical only needs to be sized to the largest load which would be the heat. You need to know what size heat coils are in it as the nameplate my not be correct. Installers are suppose to label the outside of the unit if they've used a different size heat element.

50amp sounds pretty small. That would be a reason it's blown. I'm surprized it lasted 2 yrs if that's the case but, you may not use your heat as much as your air which has a smaller draw.

Make sure the holder in the disconnect are holding the fuse tight too. That could also cause premature failure. there should be a little light or some sort on the circuit board in the air handler. If that light is on then your low voltage side of the system is ok. If it's not, there should be a little glass type fuse on the board. Make sure it's good. If it is and the light still isn't on... check for load voltage on the transformer.

 

BTW... if the installer did tap into the air handlers disconnect to get popwer for the condensor... that's a no no ! Another reason to cause the fuse to fry. You may only have a 20amp condensor but, the start up draw on that is probably close to 18amp. A 20 circuit should only have a 80% load on it. You need to have two dedicated circuits for your units.

 

guessin I will be lookin the system over in the day light this weekend.


I have a 50/2 breaker feedin the unit.

I will fire it with a new fuse and take an amp reading at the breaker.

thenI will have a better idea.

I will also check the condensor plate for F L A..


thanks !!!!


I do appreciate it!!

 

like I said... don't rely on the F.L.A. If a different coil was installed than what came from the factory... youo need to look for a KW rating for the heat element. If you find that and know the formula to get your amp... that's what you need to do.

20KW = 20000W

Divide 240V into that and you'll have your amps.