NG powered Tankless water heater

[Skip Newsom]

Back in 2008 we upgraded our furnace and water heater.
We had a Navien T-Creator Condensing 98% unit installed.

Initial reaction was it was good all in all.
Had an active teenager then that loved his showers and we do too, never ever ever ran out of hot water once flowing.
It did/does take longer to reach the faucets and shower heads than the 55 gallons of pre/reheated system did and we decided to live with it and not put in re-circulation.

It has had some issues and been serviced a few times over the years, last time I did it replacing at least a dozen o-rings that don't age well.
8 years ago the Factory actually sent out a team to do a rework on the main board and replaced at least one of the myriad of tubes pipes and such- all under warranty.

Last night my wife took a shower and afterward said hey! there's no water running from the taps at all.

I went out to the unit and there was a small river of water that had just began emanating from down under.

The panel had a code blinking, I cleared it and discovered the drain PCV outside
had frozen solid in the 8 degree at night temps.
I pulled a flexible tube out of the PVC inside and drained it into a bucket.
The heater started working fine again but there was also some water dripping from the case- Rutro.

Pulled the cover and there is a slow drip from the primary heat exchanger. And some corrosion I don't like the looks of.



The leak come from the side of the case just to the left of the black elbow going into the condenser



Debating replacing a big chunk of it vs replacing the 14 year old unit...

Any suggestions for a good replacement unit for a middle size household??

14 years ago it was $3100 installed... ah the good old days.

[Solamar]

I just replaced our 25 year old Bosch tankless water heater. The ignitor was getting finicky when air temps we're cold. Pretty good run!

New unit is from Rinai. I did a fair amount of research, and Rinai is known to be a quality unit that's lasts better than most. Assembled in USA, foreign parts I believe.

Paid $1k for it from our local plumbing distributor and installed it my self. I'm way too cheap to pay someone $2k + just to hang the unit on the wall and connect a few hoses.

Took me 2 hours to install.

[Flat Six]

+1 for the Rinnai. On our 2nd house with one. Couldn't be happier.

[unclebilly]

I replaced the heat exchanger in our Rinnai about a year ago. It was a mjor repair that i dis myself in about an hour. I need to do the blower again as moths keep getting sucked into it.

I love our Rinnai.

[Skip Newsom]

Thanks for the replies!

3 in a row for Rinnai, a trend is emerging.

I'll certainly do the R&R myself... if I can drop and reinstall 911 motors and transmissions this should be a piece of cake!

I know we paid 3k for the Navien, I believe that was installed. Shopping around for a condensing Rennai with 7 GPM flow looks to be about $1500.

An unexpected but not too expensive surprise Christmas gift to ourselves, warm water on demand.
Rennai estimates a 20 year life cycle, 14 from the Navien is no bueno!

[Evans, Marv]

I have two Rinnai R75LS water heaters that are about 13 years old. They are rated at 6gpm., which has always been more than enough. If I had to replace one, I'd do it myself like Solamar did. They just hang on the wall with some connections to be made.

[brp914]

I had a Bosch condensing, efficiency rating 1.0 installed in 2018. No problems, as expected. Just do yearly maintenance. I got 30% acetic acid off amazon and a submersible pump and braided washer lines from Lowes. Vinegar is only 5% acetic acid.

Even though designed to replace a tank heater, it took 2 pro's an entire day for the install - much more than just hanging it on a wall. Some units are designed for new construction, otherwise adapting the unit to existing plumbing can be a headache. I asked the plumbers what brand they recco'd and they said Navien.

[pete3799]

I've got a Takagi tankless the i use to heat my garage (radiant). It's been in service for roughly 10 years. Only problem i've had with it is last winter i came into the shop and the heater had quit working. After some diag i found a fusible link had gone bad. By passed it till i got a new one.