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Author Topic: Heater - system lockout check polarity  (Read 4041 times)

Offline jetboatrich

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  • Member Since: Nov 2014
  • Posts: 5
Heater - system lockout check polarity
« on: November 02, 2014, 05:58:01 AM »

My heater stopped working 2 days ago, the red light flashes twice after a few minutes and the board indicates the error is system lockout, check polarity.  It was working fine, so how would polarity change?

I have tried to reset tunring the power off and back on after a few minutes, never heard the gas start to flow or see the ignitor heat up.

Offline Joey_Bullock

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  • Member Since: Jul 2014
  • Posts: 27
Re: Heater - system lockout check polarity
« Reply #1 on: November 02, 2014, 07:49:50 AM »
Check polarity and ground at the receptacle.  Also check connections where power cord connects to furnace. 

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Offline jetboatrich

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  • Member Since: Nov 2014
  • Posts: 5
Re: Heater - system lockout check polarity
« Reply #2 on: November 02, 2014, 10:28:38 AM »
Seems to all be good as far as connections, sounding more like the board, it seems I can only get about 6 volts to my ignitor. 

Offline jetboatrich

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  • Member Since: Nov 2014
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Re: Heater - system lockout check polarity
« Reply #3 on: November 02, 2014, 10:31:27 AM »
my board is an WHITE-RODGERS Model 50A51-505, any idea where I can get it, if needed

Offline Joey_Bullock

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Re: Heater - system lockout check polarity
« Reply #4 on: November 02, 2014, 11:41:46 AM »
Sounds like the board is bad.  Try your local Johnstone Supply.

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Offline jetboatrich

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  • Member Since: Nov 2014
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Re: Heater - system lockout check polarity
« Reply #5 on: November 08, 2014, 12:12:08 PM »
The board is hot, no doubt and finding one is the hard part of this without replacing the entire furnace.

The existing board is White Rodgers 50A51-505, which I cannot find anywhere. 

second set of numbers is D340236P01 and CNT1523

Looks like the popular board that looks the same, besides not having the extension board to cnnect wires is the 50A50-473.

Just bought the home, did a lot of work before winter came and now another 2K in repairs would hurt, is there a cross refernce to this board :(

Offline niobrara

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  • Member Since: Sep 2009
  • Posts: 1267
Re: Heater - system lockout check polarity
« Reply #6 on: November 08, 2014, 12:45:08 PM »
White Rodgers 50a51-505 Ignition Control Module  ebay

Offline jetboatrich

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  • Member Since: Nov 2014
  • Posts: 5
Re: Heater - system lockout check polarity
« Reply #7 on: November 08, 2014, 12:52:27 PM »
White Rodgers 50a51-505 Ignition Control Module  ebay

Thanks, this is one of those tough decisions where the board is $300 and teh furnace is 20 years old, do you start letting it piece it out and cost me more............