Another Navien Repair

I'll say this for the standard hot water heater -- the kind with a tank -- it doesn't have a lot of moving parts and it certainly doesn't have a lot of electronics. The same can't be said for the typical tankless hot water heater. Just look at the Navien.

Navien NR-180A Tankless Hot Water Heater

The more stuff you cram into these 17" x 28" x 14" boxes, the more can go wrong. We've had problems with our system ever since it was installed in December 2010. The last fix was replacement of the flame rod assembly. Before that, we had to cut into the wall and pull the exhaust pipe down to create an incline for the condensate to drain properly.

This time around the problem was the air pressure sensor (APS). The new APS Pt# was 30000663A, and replacing it also required replacing the whole damned printed circuit board (PCB), Pt# 30000182A.

The APS is located at the top, right side of the unit.

This job went fast, less than an hour, once the problem was diagnosed, and it took time on the phone with Navien tech support to figure out what was wrong. We had, at different times, error codes 3, 10, and 12; ignition failure, abnormal air pressure, and flame loss. None of these codes made reference to the APS or the PCB.

Navien Tankless Water Heater Flame Rod Replacement

Due to continued "failure to ignite" problems (Error Code #3), we recently had the flame rod assembly on the Navien NR-180(A) replaced.

Old flame rod assembly showing oxidation and increased gap

Flame Rod Assembly Pt#30004680A

Adjusting Inclination of Navien Exhaust Pipe

See a previous post for an explanation of why this repair is being done.

Removing Navien connection to exhaust pipe

Sheet rock cut out around inlet and exhaust pipes

Condensate (~1.5") trapped in exhaust pipe

Original set of exhaust pipe

Exhaust pipe hole expanded and pipe lowered

Cover placed over open sheet rock space

Piping refit to Navien