Nordyne M1MB070ABW

[sjbanks]

I am trying to get my furnace running. I get 4 flashing LEDs on the control board which means Ignition failure/locked out. My inducer motor & pressure switch were replaced within the past three years. I don't know what to look at next. Also, I was told by a tech that I can have the fan run only but I am unable to get that going too. We are heating the house by using the gas fireplace.
Thanks for any info you can provide,
Scott

[Robert]

Hi Scott,

That is most often due to a bad ignitor/flame sensor combo or the gas valve.

Ignitor # 903110A

Gas Valve # 903596


Both can be seen and ordered through PayPal from left side here if needed :

http://www.mobilehomerepair.com/NordyneGas.html



Thanks,
Robert

[sjbanks]

Thanks Robert,
Is it possible to check these in order to determine which one or if both are bad? I see that the ignitor is the cheaper way to go, but do I need to remove the gas valve to replace it? If so, it makes sense to change both. I am glad that I found your website. I will definitely be checking in on a regular basis.

Have a blessed day!
Scott

[Robert]

Hi Scott,

Your blower motor would not run with t-stat set to Fan ON at t-Stat ?


With a call for heat, after about 30 seconds or less, you should get 120VAC at the two wires going to the ignitor.

IF so and it doesn't glow , it is bad.

IF it does glow, it should glow for about 35 seconds or so, then you should read 24VAC at the gas valve solenoid terminals for about 6 seconds.

IF burner ignites and through flame rectification, ignitor senses the flame, gas valve stays open for cycle.

Test for the 24vac at gas valve. IF it is there for 6 seconds and presuming that the gas pressure in and out of gas valve is OK, then the gas valve would be bad IF the burner did not ignite.


Also check the main burner orifice behind the gas valve to ensure it is not clogged by spider-web-eggs.

IF so or if gas pressure is not sufficient leaving gas valve, then burner flame would not be hot enough or big enough for flame rectification and gas valve would shut down.


The gas valve, mounting plate behind it and burner assembly with ignitor all comes out in one piece.

This is all the DIY to do, but it is not necessarily conclusive as there are further tests not DIY that can sometimes turn problem area elsewhere.

Check and let me know what is found.


Thanks,
Robert

[sjbanks]

Robert,
Good morning!
I used my meter to check out the ignitor. I checked the voltage going to it while connected and it was good. I disconnected the ignitor wires and checked resistance and my meter read OL which is bad, as you know. I started the furnace in order to check for the ignitor to glow and it didn't. So, my ignitor is bad. At work yesterday, we had a HVAC tech in and I explained this problem to him. He said everything that you had said to me. One thing he did say that you didn't was that I could use a propane torch to lit the furnace when the gas valve released the short burst of gas into the furnace. He assured me that this was safe because of the short burst time of the gas. I did this and my furnace lit! So now, I know that my gas valve is good. The LEDs on the control panel were solid which meant everything was good. Once the house reached temperature though, the furnace kicked off which meant if I wanted it on I would have to keep relighting it.
When I remove the burner to switch the ignitor out, I will inspect & clean the area as needed.
Thanks for sharing your knowledge.
Have a blessed day,
Scott

[Robert]

Hi Scott,

LOL, telling you that in person is a lot different from telling you that here. Also, had not determined that ignitor was bad yet either.

With that said, gas valves are components and components fail and have been known to open fully instead of the short burst you expect.


That smell would be your singed eyebrows.

You're very welcome, happy to help and be safe out there.

Let me know if ignitor replacement cures all.


Take care and best wishes,
Robert

[sjbanks]

Robert,
Thanks again. I will update you on the ignitor replacement once I have done it. It will probably be later this week. (waiting for payday)
I will try hard to keep my eyebrows on my face intact!
If I come across any additional info, I will pass it on.
Scott

[Robert]

Hi Scott,

Sounds good, glad to help out.


Take care and best wishes,
Robert

[sjbanks]

Robert,
Good Morning or Evening,
I replaced the ignitor and everything is running good. Thats for all you advice. My eyebrows are still on my face! The ignitor I replaced lasted about 10 - 11 years and I am told that this isn't normal. I plan on buying a spare soon.
Have a blessed day,
Scott

[Robert]

Hi Scott,

You're very welcome, happy to help. Try to remember us when buying the parts. Only way to ensure that the site and info remains here for future needs.


Take care and best wishes,
Robert