Seeking advise on thermister
- Thread starter Bon43
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Great Horned Owl
Well-known member
Thermisters are usually either good or bad. Unless there is just a bad connection to it, once it dies, it won't come back to life.
Joel
Joel
We have a norcold n512 . It was working fine until this week when it showed the n error. I reset the board and it ran fine for about 6 hrs when the n code reappeared. I reset the board and using the diagnostics the thermistor showed a temp of 76 degrees. I checked the fins and they felt cold. I used an external thermometer and got a reading of 45 on the fins. Put the thermistor in a glass of ice water and it still showed 76 after a few minutes. Anyone have any ideas? I was probably going to snip off the thermistor and splice in a new one. Easier than replacing without having to remove the entire unit.
Gary RV_Wizard
Site Team
How did you get a temperature reading from the thermister? Usually they are calibrated in increments that are not easily translated to degrees F. (or any other degrees).
The N code means the controller could not detect any cooling even though the cooling unit was running non stop. That is called a "No Cooling" fault and the controller shuts down the cooling unit rather than risk n overheated boiler. A thermister that gives an excessive high report could cause that, but so could many other things. Replacing the thermister is one way to rule that out, but despite the popularity of thermister reports on the internet, it's not all that common as a failure.
N5xx series service manual: http://bryantrv.com/docs2/docs/n5051.pdf
The N code means the controller could not detect any cooling even though the cooling unit was running non stop. That is called a "No Cooling" fault and the controller shuts down the cooling unit rather than risk n overheated boiler. A thermister that gives an excessive high report could cause that, but so could many other things. Replacing the thermister is one way to rule that out, but despite the popularity of thermister reports on the internet, it's not all that common as a failure.
N5xx series service manual: http://bryantrv.com/docs2/docs/n5051.pdf
Hi Gary
I used the onboard diagnostics. Press the temp set and mode simultaneously, then scrolling through to screen 3 which is supposed to be the thermistor temp reading. Just to be sure, I also used a multimeter and checked the resistance of the thermistor while on the fins and then put it in ice water. There was no change in that reading either.
I used the onboard diagnostics. Press the temp set and mode simultaneously, then scrolling through to screen 3 which is supposed to be the thermistor temp reading. Just to be sure, I also used a multimeter and checked the resistance of the thermistor while on the fins and then put it in ice water. There was no change in that reading either.
Gary RV_Wizard
Site Team
Didn't realize the N512 had a diagnostic function on the op panel - excellent! The N510 doesn't appear to havethat, so the 512 must be a newer upgrade.
From what you describe, it sure sounds like an unresponsive thermister.
From what you describe, it sure sounds like an unresponsive thermister.
