[ichosethis1]

Hi all, I have a Frigidaire package unit heater/air conditioner and my heat does not work suddenly. All was fine until the night before thanksgiving I came home and the house was down to 63 degrees and the vents were blowing cold air!! The model number of my unit is R4GA-036K072C and apparently it is made by Nordyne. I have tried already changing the ignitor, careful not to touch it, as I had read in one of the forums this is usually the problem, but even the new one does not glow. The original ignitor ohmed out at 176 ohms, while the new one ohms out at about 60 ohms. I have checked the fuses, and they are fine. I have checked for voltages at the step down transformer and they are all there. I have also checked the voltages on the colored wires coming back from the thermistat and they are as follows. Red to yellow 27.5v, red to green 27.5v, and red to white 0v. I am told that there is some safety stuff that must be happy to make heat, and would like to know is there a testing procedure for these things? Like the flame rollout switch and the temp probe, and pressure switch? When observing its operation from outside with the panel off, when I apply power the red status light is on solid for about 3 seconds, then something clicks, and the status light starts blinking about once every second, or second and a half. The exhaust fan is running, and the blower motor stays on and never no matter how I try does it shut off. The only way to stop the blower is to pull the breaker. I have been unable to find any useful documentation, and it is getting very cold in here, any help would be greatly appreciated...

[hvac1000]

This is your complete manual for service. See what the circuit board is falshing and then see page 26 to see where it takes you with the problem. Keep this for your records. Post back with what is going on. NOTE you might also check to see if the circuit board is putting out voltage to the ignitor.

http://www.nordyne.com/Literature/7086290.pdf

[ichosethis1]

Wow thanks for such a quick response, according to the documentation you provided, it appears I have a fault condition of limit circuit open. How do I troubleshoot this?

[hvac1000]

Find the limits on the wiring diagram if possible, The limits might also have a reset buton in the center. That info I sent you will show it on the wiring diag.

[ichosethis1]

Thanks for the help, I will study the diagram again and try to figure it out, but I have not been able to find any kind of reset button whatsoever.

[hvac1000]

Usually the reset is a very small button in the center of the disc limit control. I have no way of finding it for you since I am her and the unit is at your place but follow the wires on the diagram might help.

[mygirlsdad77]

Bypass one limit at a time(flame rollouts, high limits). Just unhook the wires from the limit, and hook the two wires together. See if the furnace works. If it does, replace limit. This is only a trouble shooting test, do not use furnace while limits are bypassed. Good luck and lets us know what you find.

[ichosethis1]

OK progress? Sort of. After going over the diagrams that hvac1000 was so kind to provide, and following the blue wires, I have found my limits. (no pun intended). I have now, I think, fixed the original problem, being coroded terminal plugs to the limits. And finnally got the sucker to glow. Problem is about 3 seconds after starting glow, it promptly blew up! Now remember this was a brand new ignitor, and I used gloves to install it so as not to possibly touch the thing. So I got my old ignitor back out of the box and re-installed,again wearing gloves, only now after applying power, I get two blinks out of the red light indicating pressure switch stuck open. And nothing further happens.(the blower is finally staying off, yay!) So, what do I do about the pressure switch staying open error? I still have not found any sort of a reset switch in this unit. And as far as I can interpret the schematic, the pressure switch is supposed to be in a normally open state, which the ohmmeter confirms it is.

[hvac1000]

The ignitor blew up DANG. How much voltage is being fed to the ignitor off the board? That is a 220/240 volt unit but I figured they just used one leg of the 220 which would be 110 to fire off the ignitor. Cycle the disconnect off for 5 minutes then re-energize the unit abnd do a start up cycle. I need to know how much vlotage is being supplied to the ignitor circuit.

[hvac1000]

Here is your parts list for your unit.


http://www.nordyne.com/Literature/707786m.pdf

You might have been sold the incorrect ignitor??

[ichosethis1]

I have had it off since last post I just re-applied power and the red light still blinks twice. The voltage reading across the ignitor is 15vac

[ichosethis1]

Agreed, may very well have sold me the wrong one as it was a bit shorter. However I have switched back to old ignitor, and now have this pressure switch problem since the explosion

[hvac1000]

15 volts will not cut the mustard. Depending upon your system they are usually110/120 AC or 24 vlots A/C

Jump the pressure switch to test it. Do not leave run under these circumstances just test.

[hvac1000]

i have had it off since last post i just re-applied power and the red light still blinks twice. the voltage reading across the ignitor is 15vac

Does your ignitor look like one of these?

[hvac1000]

Does your ignitor look like one of these?

Or this

[ichosethis1]

Does your ignitor look like one of these?

Yes like 41405

[ichosethis1]

15 volts will not cut the mustard. Depending upon your system they are usually110/120 AC or 24 vlots A/C

Jump the pressure switch to test it. Do not leave run under these circumstances just test.

OK, I just jumped the pressure switch and now I get 3 blinks from the red light indicating that now the pressure switch is stuck closed.

[hvac1000]

Ok you have a regular one. Standard 110/120 volts. That is the voltage you should be reading at the circuit board going to the ignitor. Try to temp jump the pressure switch but before you do that reset the electric again.

[ichosethis1]

Ok you have a regular one. Standard 110/120 volts. That is the voltage you should be reading at the circuit board going to the ignitor. Try to temp jump the pressure switch but before you do that reset the electric again.

I just tried to jump the pressure switch but it gave me a 3blink pressure switch stuck closed error and did not ignite the ignitor

[ichosethis1]

i just tried to jump the pressure switch but it gave me a 3blink pressure switch stuck closed error and did not ignite the ignitor

Electric is currently removed from unit