First time furnace repair. Any advice?

**beenthere** · 04-11-2009, 08:52 PM

Probably a polarity problem.

Check your wiring, and your grounds.

kenmac · 04-11-2009, 08:56 PM

It doesn't sound like ps.. You can jump it out just for testing.. Where did you get the board ?? operation is controlled by the board

klas · 04-11-2009, 09:53 PM

Polarity shouldn't be an issue. I plugged in everything the same way as it was before.

kenmac >Can you be more specific about "jumping out"?

kenmac · 04-11-2009, 09:58 PM

The ps switch will have 2 wires attached. connect them together.. WARNING.... This is a safety & shouldn' t be left jumped out.. Only for testing

kenmac · 04-11-2009, 10:03 PM

Quote:

Originally Posted by klas

I checked the code with 5 blinks... "Flame sensed when no flame should be present" Maybe that will give some ideas?

Only idea this gives me is the board / sensor says there is a flame there when no flame should be

**beenthere** · 04-12-2009, 08:22 AM

Quote:

Originally Posted by klas

Polarity shouldn't be an issue. I plugged in everything the same way as it was before.

Sometimes new boards are a bit more sensitive then the ol board.

And a resistive ground connection will cause it.

klas · 04-13-2009, 11:04 PM

well, put a new pressure switch just to test it out and that did not resolve the issue. I even took the front fan apart just to check it out. I am really pulling my hair on this.

klas · 04-13-2009, 11:13 PM

wow, i just noticed 6 blinks. it's not 5 as I initially thought. 6 blinks related to polarity issue. Can someone tell me how do I troubleshoot this issue?

**beenthere** · 04-13-2009, 11:18 PM

I could swear I said a polarity problem earlier.

Recheck your electrical connections.
Recheck your ground connections.

Has any electrical work been done in the house recetly before your furnace stopped working.

klas · 04-13-2009, 11:25 PM

well it's odd. on a video it showed 6 blinks, but i just checked again and it actually blinked 5 times. Nevermind, false alarm about the blinks...

btw, you gave me an idea about connections... technician was unplugging things and plugging them around. Could it be that he plugged in something to the wrong place? Can you tell from the picture if connections are correct?

klas · 04-13-2009, 11:36 PM

Unfortunately, I did not take a picture prior to technician

**beenthere** · 04-13-2009, 11:47 PM

Its acting like a dirty flame sensor, or the pressure switch opening during the burner run time.

A poor ground can cause problems with flame sensing.
A loaded ground can cause a false flame sense problem.
Check for voltage between neutral and ground.

Got some rust in it also. Time to check the heat exchanger for cracks and holes.

klas · 04-13-2009, 11:57 PM

I might try replacing flame sensor as well.

hvaclover · 04-14-2009, 12:20 AM

Try checking if the pressure tap off the inducer is plugged. Could be causing the press switch to fluctuate.

klas · 04-14-2009, 01:20 AM

don't see any pressure tap

04-11-2009, 08:52 PM	#31
beenthere An old Tradesmen Join Date: Oct 2008 Location: PA Posts: 19,045	First time furnace repair. Any advice? Probably a polarity problem. Check your wiring, and your grounds.

04-11-2009, 08:56 PM	#32
kenmac HVAC / Plumbing Join Date: Feb 2009 Posts: 1,801	First time furnace repair. Any advice? It doesn't sound like ps.. You can jump it out just for testing.. Where did you get the board ?? operation is controlled by the board

04-11-2009, 09:53 PM	#33
klas Member Join Date: Apr 2009 Posts: 30	First time furnace repair. Any advice? Polarity shouldn't be an issue. I plugged in everything the same way as it was before. kenmac >Can you be more specific about "jumping out"?

04-11-2009, 09:58 PM	#34
kenmac HVAC / Plumbing Join Date: Feb 2009 Posts: 1,801	First time furnace repair. Any advice? The ps switch will have 2 wires attached. connect them together.. WARNING.... This is a safety & shouldn' t be left jumped out.. Only for testing

04-13-2009, 11:04 PM	#37
klas Member Join Date: Apr 2009 Posts: 30	First time furnace repair. Any advice? well, put a new pressure switch just to test it out and that did not resolve the issue. I even took the front fan apart just to check it out. I am really pulling my hair on this. Last edited by klas; 04-21-2009 at 10:06 PM.

First time furnace repair. Any advice?