Just moved into a new construction home. The water heater is a Rinnai tankless, which I have no experience with. It has a digital temp gage in the closet, and it looks like it tops out at 120 degrees. The issue we are having is it doesn't seem like the water ever gets very hot. The kitchen sink is on the opposite end of the house from the unit, and it would expectantly take a little longer for the hot water to reach it. That said, it never gets hot enough to need to pull your hand out from under it. Anyone know if this is normal, or is there any fix for this?

If it's far enough away, then your pretty much sending hot water through a copper heatsink. It's just science. At your kitchen, I would think that a 110v instant water heater would be a better choice for the sink AND the dishwasher.

How far away is it? My tankless heaters are all within about 35' from their point of use. If I had to send hot water from the one at the master to the kitchen 100' feet away, I would imagine it would not only take all day to get there, it would have lost quite a bit of temperature when it did.

To test this theory out, I would measure the temperature of the outlet closest to the water heater. Let it run for a few mins before testing. Get that number. Then test your kitchen faucet. KEep in mind that there is a slug of mixed luke warm water in the pipe. Measure temp at the sink. It should rapidly increase at first and as it runs, it should eventually get up to a similar temp as the other....maybe not...but somewhat close. If so...well...that's just the way heat and dissipation works.

How far is the heater from the kitchen faucet ?

Rinnai's have a jumper switch in the control board that will allow you to bump up the temperature past the 120 degree max. It will only go up to 140 degrees though I think.

Enviroag02 said:

---

Rinnai's have a jumper switch in the control board that will allow you to bump up the temperature past the 120 degree max. It will only go up to 140 degrees though I think.

---

Yep, you can find how to up it via google.

Enviroag02 said:

---

Rinnai's have a jumper switch in the control board that will allow you to bump up the temperature past the 120 degree max. It will only go up to 140 degrees though I think.

---

Awesome, thanks for the tip. I found the video on google last night and was able to get it bumped to 140.

Just be careful at the 140 because that can burn your skin. If you run something long enough at full heat, I bet you can get too hot of water to that location.

I had the same problem and bumped to 125 and now have no issues.

Deboss is right. Our plumber was hesistant to leave it at 140 after I changed it because it wasnt hot enough. Turns out it wasnt a temperature setting issue. Sediment from a line break repair had reached the water heater and plugged a filter. That was causing the heater to cut in and out while drawing hot water. We are back down to 130 now. 3200 sq foot one story with one tankless Rinai RL94iLP.

Enviro, how long does it take for hot water to reach opposite side of the house with the faucet on? Just out of curiosity.

havent timed it, but I will tonight. Will let you know.

So my water heater is in my garage just about as far from my guest bathroom as possible. I timed it at 56 seconds to get hot.

120-125 is pretty hot. I agree w/ others that the temp might not be the real issue.

Parents house has a longer wait time than yours for hot but it eventually gets there at 120.

Just used a digital thermometer on both locations. My hot water heater is set at 130 degrees. I got 126 degrees at both locations (near the water heater in the mast bath and all the way across the house in the guest bath)...no difference at all. I have Pex plumbing btw.