I have problem with Navien NCB-190/060H Error Code E031-00

[Rockyyang]

Modle:NCB-190060H(NG)
I am new owner with this Condon. I thinks the heater is purchased 2-3 year ago.
I got a problem with Space heat when I turn on space heat the Boiler will run 5-10 second and pop out Error 031-00 Overheating of burner check Burner. the pressure is 15psi when the heat start will up to 25 psi motor is running good I can hear the water flow go through every room and the temperature going up.
I have cleaned the filter and trash cap and flushing the heat exchange the problem still have. The DHW is running good not any problem.
I using the Space heat Two months no problem before it just happen two days ago .

Found something:
when I drop the water out the water pressure will down to 0 quickly and when I closed the valve I can see the pressure on the screen will up to 8 psi and stop there I need give pressure to 12 psi and the Boiler will run and give code 777-00 Lwco and need give Pressure to 25 Psi Drop water to 12-15 psi then restart the boiler. The boiler will working.
I have Changed EX-Tank and water pressure Regulator Problem still have.
Can someone help me out?
Thank you so much!

2/15/2025
Update
problem solved by changed a Temperature Fuse .
1.E031-00 problem is indicate the high Temperature of burner in my case I check the burner and changed new PBC exclude those problem .the water Temperature of return and support is normal the water Flow is fine. for the problem solve we need know what sensor cause that problem.
Thanks for anybody help me fig out problem here and Special Thanks Fitter30 thank you so much for your Help.
Hope my experience can help some one.
By the way the Navien TECH service is not GOOD for me they don't even answer Because you are not license even if you just want to know normal feature Like the Water Flow the Water pressure or some parameter. That is not good for someone Person can't affordable the cost. Every Body know it is very expensive for labor I was ask the Installer they told me $300 for diagnosis and $200 Per hour for change part not include part cost. If you don't know how to fix the problem you need to pay or stay in cold room in winter.
This link is navien service manual

Download Navien NFC-175 Service Manual | ManualsLib

www.manualslib.com

At last always Cut the Power and GAS when you want to fix or check the heater .Don't try if you don't know how It working!

 

[Fitter30]

There is a expansion tank that might need the air adjusted in it. Take some pics of boiler piping and pumps. Don't stand to close want to see how the system is piped. Tools needed to check and adjust ex tank 0-50 lb tire gauge and a hand tire pump or air compressor. One or two story house. Boiler in a basement?

 

[Sponsor]

 

[Rockyyang]

There is a expansion tank that might need the air adjusted in it. Take some pics of boiler piping and pumps. Don't stand to close want to see how the system is piped. Tools needed to check and adjust ex tank 0-50 lb tire gauge and a hand tire pump or air compressor. One or two story house. Boiler in a basement?

Thank you so much for your feedback. I am living a Condon the water heater is on the same Floor. I just fixed the pressure problem from changed a water pressure sensor. Now the pressure comes to normal 12Psi.but the problem still have I am no idea not parts have the problem .is it 3 way valve or Water adjustment valve?
I am plan change a Hight Limit switch this switch is beside the supply temperature sensor when the problem appear I check the return and supply temperature are 118 same as my setting.
When this error happened I hear sound like so much air in the heater even if already run air pure mode let the air out.
Any suggestion?
Already replaced EX-Tank and water pressure Regulator and water pressure sensor!

 

[Rick Carone]

Modle:NCB-190060H(NG) SN:2163W2133156063.
I am new owner with this Condon. I thinks is purchased 2-3 year ago.
I got a problem with Space heat when I turn on space heat the Boiler will run 5-10 second and pop out Error 031-00 Overheating of burner check Burner. the pressure is 15psi when the heat start will up to 25 psi motor is running good I can hear the water flow go through every room and the temperature going up.
I have cleaned the filter and trash cap and flushing the heat exchange the problem still have. The DHW is running good not any problem.
I using the Space heat Two months no problem before it just happen two days ago .

Found something:
when I drop the water out the water pressure will down to 0 quickly and when I closed the valve I can see the pressure on the screen will up to 8 psi and stop there I need give pressure to 12 psi and the Boiler will run and give code 777-00 Lwco and need give Pressure to 25 Psi Drop water to 12-15 psi then restart the boiler. The boiler will working.
I have Changed EX-Tank and water pressure Regulator Problem still have.
Can someone help me out?
Thank you so much!

It sounds like your system is battling pressure fluctuations—maybe from a hidden leak or trapped air. Try hunting down leaks, bleeding the system, and checking the pressure switch for a smooth, hassle-free heat flow!

 

[Rockyyang]

I am use Test mode for all test and found Flow Control Valve 0% Feedback Mix Valve 50% Feedback Is that abnormal?
I check the Status Information of DHW Flow show 4.5LPM is that same Flow control?

 

[Fitter30]

Boiler is piped wrong. Take some pics of the rest of the piping and pumps.

 

[Breplum]

The piping doesn't look right to me and I am not even a specialist on combis.
To note: the boiler side is supposed to use closely spaced tees or the specific manifold Navien sells.
And, the DHW side (really both sides) must have descale bypass union kit.

 

[Rockyyang]

The water pressure Solved by change a new water pressure.But the problem still have. I have changed Hight limit Switch and Exhauste Sensor.Checked the fan and Damper every things is good.Is it the problem from Heat Exchange?
Someone told me Change PCB is it works?

 

[Fitter30]

Clean the air inlet filter? Top left. Here's a service manual it's not your boiler but it's a NCB. Page 43 is for the servicer. Hi limit trips at 197.6°°, exhaust 230° for 10 minutes. Need to look at E- flow rate, P - exhaust temp and R aws pressure set point.

NAVIEN NCB-150E SERVICE MANUAL Pdf Download

View and Download Navien NCB-150E service manual online. NCB-E Condensing Water Heaters. NCB-150E water heater pdf manual download. Also for: Ncb-180e, Ncb-210e, Ncb-240e.

www.manualslib.com

 

[Rockyyang]

Clean the air inlet filter? Top left. Here's a service manual it's not your boiler but it's a NCB. Page 43 is for the servicer. Hi limit trips at 197.6°°, exhaust 230° for 10 minutes. Need to look at E- flow rate, P - exhaust temp and R aws pressure set point.

NAVIEN NCB-150E SERVICE MANUAL Pdf Download

View and Download Navien NCB-150E service manual online. NCB-E Condensing Water Heaters. NCB-150E water heater pdf manual download. Also for: Ncb-180e, Ncb-210e, Ncb-240e.

www.manualslib.com

Thank you for your Feebback .Air Inlet Filter is clear The Exhaust is 122 and DHW Flow rate is Around 4.LPM when using DHW the SH Flow Rate is show Calculating。Water pressure 13.psi.
The Flow control Valve status is 68% and Mixing Valve status is 2%.
When the DHW working the Flow Control Never up to 68% Arount 65%.
All the pictures is when the Machine stop Heating
AWS Target 0.4 V Current 0.47V
Fan Target RPM 30008 RMP. Current :30007 RPM!

 

[Fitter30]

Your not moving any water through the boiler side. Either air bound are the pumps bad in heater. Air scoop is the chrome cap on top of air scoop loose? Needs to be.

 

[Rockyyang]

Your not moving any water through the boiler side. Either air bound are the pumps bad in heater. Air scoop is the chrome cap on top of air scoop loose? Needs to be.

Yes i took pictures when it stop working.How do i check the APS? Every things works fine after 5-10 minutes will overheating Error 031
I checked the exhaust Temperature rise very quickly when the DHW useing 1 Min it will up to 122 F but not reach 149.
Is it abnormal？

 

[Fitter30]

Error Code E031: Overheating of Burner If your water heater displays error code E031, it means the burner is overheating. This occurs when fuel residue accumulates on the burner. To fix this issue: 1. Contact the Navient Technical Support Team at 1-800-519-8794.
Burner could be sooted up.

 

[Breplum]

Error Code E031: Overheating of Burner If your water heater displays error code E031, it means the burner is overheating. This occurs when fuel residue accumulates on the burner. To fix this issue: 1. Contact the Navient Technical Support Team at 1-800-519-8794.
Burner could be sooted up.

If he is not a plumber, Navien generally will not walk him through much. It is too much of a waste of their time.

 

[Rockyyang]

If he is not a plumber, Navien generally will not walk him through much. It is too much of a waste of their time.

Navien Not support end user They don't answer my qustion.I am not license Plumber but i did Plumber worker and Electric many years.
I talk to the License Installer they are very expensive i Can't afforable that. $300 for the diagnostic One hour $200 for install not including Part fee.
I afraid the problem from Heat Exchanger itself you Know it is cost $800 and more Although it has 10 years Warranty not help for end user.
Hope the problem is not from Heat Exhanger.Godbless ME！

 

[Rockyyang]

Do you know hwo to flush the Heat Space Exchanger? I was try to Flush but no Water comes out from Supply .DHW is working.

 

[Rockyyang]

Error Code E031: Overheating of Burner If your water heater displays error code E031, it means the burner is overheating. This occurs when fuel residue accumulates on the burner. To fix this issue: 1. Contact the Navient Technical Support Team at 1-800-519-8794.
Burner could be sooted up.

Do you know how to flush the Heat Space Exchanger? I was try to Flush but no Water comes out from Supply .DHW is working.

 

[Fitter30]

Do you know how to flush the Heat Space Exchanger? I was try to Flush but no Water comes out from Supply .DHW is working.

Try backflushing with heater off supply to return. Possibility hear exchange was overheated and has a tube twisted up. Boiler water looks black and stinks?

 

[Rockyyang]

Try backflushing with heater off supply to return. Possibility hear exchange was overheated and has a tube twisted up. Boiler water looks black and stinks?

The water looks very clear after sevel times testing. I remember Fist time change water is very Black and oil and stinks.
Navien NBC190 not allow to Flushing Heat Space . Some one said because the 3 way Valve Stop water go out. I was tryed Flush it but no water comes out from Supply .but i Found out may be i can Flush the water out of PrssureRelief Valve Adapter.
Can i do that Flush water come in to Heat Return and Out of Pressure Relief valve?

 

[Rockyyang]

I use endoscope to check inside Burner It look clean.
Are there fuel residue accumulates?
When it burn you can see much red point inside.