Our regular 50 gallon tank water heater is showing signs of petering out. It’s just over 11yo. I’m sorta interested in tankless units, not expecting to “save” money on gas or water bills… I just like the idea of near instant hot water. It takes damn near 5 minutes for the kitchen sink to start warming up. Estimates are all over the place so far.

Don't expect the wait times for hot water to go down unless you move the tankless closer to the faucets than the current heater, or you hook up a recirculator.

I've had excellent experiences with Rinnai. We had two at our last house that lasted over 18 years I think. We put one in our new house before we moved in.

My home is 8.5 years old and came with a Rennai installed in the garage. Never ending hot water is nice.

Make sure the installer puts in the recirc connections/valving so you can run vinegar or descaler through it annually. I purchased this descaler pump kit and use annually.

Had a Rinnai at our old house [in Todd's hood].
Had to replace the ignitor, but otherwise trouble free.

If you want the hottest out of it, find the highest it'll go without interruption. We were able to outflow [I think] outs a few times. Washer, dishwasher & a shower at the same time got a few spurts of cooler water.

Not sure what ours is now, but similar. Get enough hot demand & sometimes it can't keep up.

I sold my gas water heater and installed a Rinnai roughly ten years ago. Not one issue since then. I love it, and I've saved a bunch on gas not having to keep 50 gallons of water hot all the time. If I had a complaint it would be that it takes a minute-plus for the hot water to reach the faucet, but...you get used to it.

It will take the same amount of time or longer to get hot water at the fixture. When it's not in use, the water from the heater to the fixture gets cold and a tankless has to heat the water first and then send it the full line to the fixture replacing all the cold water. Tankless only is an improvement in endless hot water.

If you want near instant hot water at the fixture, you need a re-circulation pump. You put a check valve crossover at the furthest appliance connecting the cold and hot water lines, then put a pump on you water heater that will pump hot water into the system that crosses over to the cold line at the valve and returns to the water tank. They have timers on them so you can set when you want it to go off. I put mine to run for 15 minutes, then off 45 minutes starting 30 minutes before my wife wakes up. This gives me hot water in about 10 seconds. If you wanted faster you could run it longer.
Here is a link to one at home depot.
https://www.amazon.com/Grundfo...584138871755756&th=1

Thank you all for the input. Just read responses a min ago cause I fell asleep at 9:30. I’m fighting a nasty respiratory bug.

I’m wondering if jeffxjet’s suggestion is the way we should go. One plumber offered this solution as well. A new 50g tank and the pump was still significantly less than a Rinnai system. Our biggest problem isn’t necessarily running out of hot water but rather waiting for hot water.

Also, I'm reading about recirculating pumps built into some tankless units like Rinnai… this would nearly fix the waiting for hot water also, correct?

The tankless wont help with the waiting for hot water, the pump will. I had the pump in my old house because it was a long distance from the heater to my appliance. When I moved to my new house, I took the pump with me but left it packed because the runs were shorter. After a year of waiting for hot water i got tired of it again, dug the pump out and reinstalled it and everything was right in the world again. It takes less than 10 seconds to get hot water now. And its a very simple install, best upgrade you could do. And the plus side is that you can get the pump now, and wait until your water heater fails later to replace it. You can do one at a time, unless you want to replace the heater at the same time.

Five years ago we moved the south-side water heater location from the attic to the north-side garage floor and had the plumber run insulated pex lines through the attic. Like Jeffxjet described above, the plumbers installed a Taco brand re-circulation pump and analog timer which has been the near-perfect solution for us. In fact we get hot water faster than when the water heater was over our heads. All I had to do was determine the best times for the re-circulator to start/stop based on when we need hot water on that end of the house. The analog dial simply needs to be set to current time, then flip the switches in 15 minute increments across the face of the 24 hour dial. Not sure about digital timers and what information gets lost when the power goes out, but all I need to do is reset the dial to the current time since we don't lose the start/stop times.

Getting one of these is a no-brainer if you have a long run between hot water heater and the sink/shower/appliance you're using.

Ours is a Navien, but time to hot water seems to simply come down to which faucet is turned on. I just think tankless is the way to go. period.

I'll echo the good reviews. Mine came with the house and now I wouldn't be without one. Yes, it takes a while for the hot water to get to the furthest faucet, but it's not a terrible wait.

As tatertodd said, make sure it's plumbed to allow yearly flushing. And that's very easy to do.

Our previous home was built with the recirculation pumps. Instant hot water at every location!

The pump has a learn mode with an internal "clock" which remembers higher demand times, e.g. morning showers. But it forgets everything with a power interruption. Not a good mode for lots of reasons.

Power draw was minimal for that pump. I ran it 100% of the time. The house was very well insulated, so it really was not inefficient to circulate the hot water.

There was a thermostat mode where it sample the return water temperature once in a while (unspecified interval) and if not warm enough then the pump would run. This mode was not good at keeping water hot at the faucets. It is possible the pump location was not ideal for this mode.

If you have such a pump installed, ask the plumber to configure it for easy replacement if it fails.

We replaced the 50 gal gas water tank with a Rinnai, mounted it outside so we didn't have to make an exhaust run.

Yes it takes a little time to get HW at the farthest connections, but it's not really that bad, you're not waiting 10 minutes for HW.

Get the largest one you can, so you can run multiple appliances/showers if needed. Especially if you have a house full of teens.

NG is the least expensive, then LP, electric are not really efficient vs a tank. Out LP bill cut in half when we dumped the gas tank, the tankless only uses fuel when you need HW, tanks are constantly working to keep the water hot consequently they use more fuel.

We have one of their heaters and has been great. Good quality. I like them. Have no experience with their water heaters.
Sounds like you need a circulation pump in your hot water line so you do not have to wait for hot water and waste water waiter for hot water to arrive.

When our water heater died, we replaced it with a Rinnai tankless. Absolutely love it!!! The big win though was not changing the wait for hot water, it was not running out of hot water with two teenagers taking showers.

At our last house (around 25 years ago) it was a *long* way from the water heater to the master bath. We ended up plumbing a return line to the water heater and installing a recirc pump. That did away with the wait for hot water.

When we went to tankless at this house, we were told that a recirc pump wouldn’t work with tankless. Supposedly there was one tankless out there that had its own recirc pump built it, but it was crazy expensive.

Also, in my mind there are two benefits to tankless: 1) You are not heat water unless you need hot water. (A vacation home that you occupy occasionally would likely see significant savings from not keeping 50 gallons of water hot when you’re not around to use it. Yes, you can turn it on and off, but you will have to wait a bit while it heats.) 2) You are not limited to 50 gallons of hot water. No danger of the kids running you of hot water.

With a tankless, instead of cranking it all the way up to make the water as hot as possible to minimize the chance of running out, you can use a lower setting and just mix in less cold water for the desired temp. This may be safer, though I never managed to scald myself with the tank turned all the way up.

Some years after plumbing in the recirc system in our last home, I became aware of systems that go under your sink and pump from the hot water line to the cold water line. I assume the work on a timer or more likely a temperature sensor, and when the water in the hot line goes cold, fire up the pump and pump water from the hot line to the cold line until the water warms up. No additional plumbing lines required, just connects to the hot and cold supplies for a sink at the furthest point. They might even have been available when we did the work on the last house, but I didn’t know about them. I have zero experience with these systems and don’t know how well they work are don’t. I do know that a recirc pump at the water heater with a return line will do away with your wait for hot water.

Whether recirculating hot water, tankless, or both is best will depend on your situation. The recirc was awesome in the last house. The runs are shorter in the new house and the water heater much closer to the master, so we prefer the tankless here. Only you can decide what is going to best meet your needs.

Lotsa good info guys. Thank you again. I’ve got one more plumber coming tomorrow for a third estimate, figure I’ll make a decision after that.

So I’m reading more about tankless Navien and Rinnai..the two systems every plumber seems to recommend here, and I’m reading that some models say they have a “recirculating pump” built in..?? Is this going to rectify the issue we’ve talked about above (waiting 5 min for hot water at my kitchen sink)?

quote:

Originally posted by dry-fly:
So I’m reading more about tankless Navien and Rinnai..the two systems every plumber seems to recommend here, and I’m reading that some models say they have a “recirculating pump” built in..?? Is this going to rectify the issue we’ve talked about above (waiting 5 min for hot water at my kitchen sink)?

I looked on amazon for the rinai with built in re-circulation pump, and it looks like it satisfies your requirements, no direct knowledge but from the brochure it seems correct.

quote:

Originally posted by dry-fly:
Is this going to rectify the issue we’ve talked about above (waiting 5 min for hot water at my kitchen sink)?

It won't be five minutes. From the heater to my kitchen sink is roughly 40 feet. It takes about a minute to get there. The bath on the far end of the house...a little longer,

Again, not a big deal...you get used to it and it's a small price to pay.

We have put in over 100 instant hot water heaters in the homes we built…

First, I’m assuming that you want a gas instant hot water heater vs. an electric one. Good.

The location of the water heater will play a big part in how long it takes the hot water to reach your faucet etc. we always tried to install one nearest the master bath. We frequently installed a second one in many of the larger homes we built too (>5000SF).

We started out installing Rinnai heaters and they were very dependable. The last few years of my business we switched to Navian primarily due to 2 reasons. First, they were slightly more efficient and 2, they could use a smaller vent flue which made them easier to place where we wanted too.

Both are very good. In my own home that I built in 1997 I installed a propane fired tanked water heater and tracked my propane usage for several years. When that heater died I switched to a Rinnai and my propane consumption DROPPED by 30%.

So needless to say I’m a big fan.