Wow. This is so completely opposite my experience that It's hard to even compare!
I installed a Rinnai On-Demand (propane) water heater in 2009 , and it's been utterly reliable. I run it on well water, with moderate mineral hardness.
Saving money? Probably not a lot. Up front costs were fairly high, and Propane is a bit more expensive than Natural gas, so that's a factor.
Lifetime? So far...10+ years. Repair costs: $0 so far. Operating Cost? Highly dependent on propane cost.
Efficiency? I've got mixed feelings on this. The boiler is highly efficient, but overall efficiency? I dunno, electricity is cheap. But, I don't pay for hot water sitting in a tank. So, who knows?
Bottom line though, the hot water just doesn't run out, Which frankly has WAF through the roof.
Agree completely. I also installed a Rinnai a few years ago and it’s been great. Added bonus for me is extra storage space. I had two tank water heaters in the utility room in my garage and now I have two Gladiator cabinets that store all my toys.
Now on the flip side I sometimes wish hot water would run out when my kids take showers
One thing I have to say, with my tankless, is that I get more variability in temperature when I take a shower. I can definitely tell when my 50 foot trunk of cold water finally gets real cold water from the ground pipe.
I will likely switch my pressure balancing shower valve to a full thermostatic valve. If you are thinking of going tankless on a new build/large reno, I would definitely recommend thermostatic valves for all your showers.
I have the rheem platinum with integrated recirculation pump btw, Maybe Rinnai has better "temp control", but according to my tests the Rheem maintains my requested 120F temp with rock solid accuracy at full hot, so I suspect it is indeed some latency and variations with cold water temp in the cold line that is causing temp fluctuations at the shower.
I only see variation in temp, when household demand increases while using the shower...e.g., another shower comes on, someone starts the clothes washer, which pulls down the cold a bit, etc.
On the smart front, about the only things I could do on my older model would be add a power monitoring plug, and possibly a gas detector. Newer models probably offer some telemetry it might be worth grabbing for one of those Node-Red, grafana things.
I have a Rinnai tankless, but mine definitely doesn't have the Recirculating pump. That's a relatively recent addition to the line. If you have one, it should operate automagically when you turn on the hot water (as I understand these things).
Someone on here does have a recirculating pump, if I can remember who, I'll add it here.
I put a thermostatic valve in our shower when we did a remodel. Best upgrade ever! Never again even noticed the dishwaswer, washing machine, etc. Even flushing the toilet right next to the shower made no difference in the shower temperature. Can't recommend one enough.
The one I installed was from Delta. They call their thermostatic valves "TempAssure". I just looked at their website, and they have lots of different styles all called "TempAssure 17T", which sounds familiar. I think this may be the one we got: TempAssure® 17T Series Valve Only Trim | Delta Faucet (we didn't pay THAT much!), but I'm not 100% sure. I'm sure all the innards are the same. The remodel was 4 years ago, and we moved out of that house 2 years ago. But I'll install one of these again the first chance I get. Having said that, the Moen in our current shower holds temp very well also. I have no idea what it is. Perhaps all thermostatic valves work equally well. Perhaps a pressure balanced valve would be fine for me, and maybe that is what I have now. All I'd ever known was simple valves, usually one each for hot/cold. The change to the thermostatic valve was wonderful...
As I recall Delta's innards vary, and you can buy different valves to go in your valve body, but it's been awhile. I should look into it though, as I do get a lot of variation in temps when various things come on in the house.
@scottgu3 is correct I do have the built in circ pump and love it. I have mine automated with the shower light in each bathroom where it will turn on with the light. So we all wait a few minutes before getting into the shower or just tell Alexa to turn on “hot water”. I did this with my old pump too. With the Rinnai I had to solder wires to both sides of the circ pump button on the controller to virtually/digitally press it with a dry contact relay. Happy to provide more details if interested.
I don’t have a button (attached a pic) but the spec sheet from the builder (Lennar) says it has a built in recirculating pump. Maybe they made a mistake?
You may have a built-in recirculation pump, but it may not be plumbed with a dedicated line (which would be a shame). There is also an adapter that allows you to use your existing water lines IIRC, and that may be what is installed on yours. Not as good as a dedicated line as it has side effects (ie lukewarm cold water when running), but better than nothing especially if you don't need cold water from the tap.
Look for an additional 3/4" brass port with a brass plug on your unit, that's how my Rheem Platinum came. They are usually set to "no-recirculation" from the factory.
FYI mine has 3 options for recirculation, on demand (button or Alexa style), pre-programmed for certain times of day, or "fuzzy logic", where it learns your hot water use, and adapts its recirculation schedule to anticipate your needs.
Not sure how good the "learning mode" is, but it sounds cool, so I will try that first when I get around to plumbing mine (recirculation line was run, just need to connect it).
Thanks for the info! I'm not sure if I have a dedicated line (attached a picture).
On the feature sheet the builder said "Rinnai® tankless water heater with built-in recirculating pump" but according to the model number on the unit (RU199iN) - it doesn't have a built in recirculation pump (unless I made a mistake).
