Need help disabling the temperature lock on a Navien NPE 240A

[Ben Bonnett]

I just replaced an NR 240A with a NPE 240A. When I tried to increase the temperature to 125 degrees I got a "Lock" display. On the NR units with the remote controllers, this was easy to disable. I cannot figure out how to do it on this unit with the built in display. The manuals don't seem to address this. Any advice? FYI, the "Lock" display shows up even if you try to turn the temperature down. Thanks for your help.

 

[Ben Bonnett]

I just replaced an NR 240A with a NPE 240A. When I tried to increase the temperature to 125 degrees I got a "Lock" display. On the NR units with the remote controllers, this was easy to disable. I cannot figure out how to do it on this unit with the built in display. The manuals don't seem to address this. Any advice? FYI, the "Lock" display shows up even if you try to turn the temperature down. Thanks for your help.

I just wanted to leave an update. The NPE has a lime alarm feature that will remind you in 6 months, 12 or 24 to flush the system. We have been flushing the customer's water heater every 6 months, so this feature seemed worth using. To set the 6 month alarm, you flip dip switch 7. Dip switch 7 also locks the temperature setting from being changed. This is not in the manuals or online, but the technical service department knows about it. To fix the problem, I just had to flip off dip switch 7 and instantly had temperature adjustment control back. Hope this helps if anyone else encounters the same situation.

 

[Sponsor]

 

[NTntntnt]

I just wanted to leave an update. The NPE has a lime alarm feature that will remind you in 6 months, 12 or 24 to flush the system. We have been flushing the customer's water heater every 6 months, so this feature seemed worth using. To set the 6 month alarm, you flip dip switch 7. Dip switch 7 also locks the temperature setting from being changed. This is not in the manuals or online, but the technical service department knows about it. To fix the problem, I just had to flip off dip switch 7 and instantly had temperature adjustment control back. Hope this helps if anyone else encounters the same situation.

 

[NTntntnt]

Thanks for the tip. Yeah, I had to switch dip switches 7&8 to the off position in order to change the temp.