Tankless Takes Forever To Get Hot Water To Shower

[ChaseGizmo]

I had a tankless Rinaii water heater installed in a house just built. It is located about 60 feet from the farthest fixture.

When I open a faucet or try to fill the tub it takes forever for the water to get hot.

I am wasting gallons of water waiting.

What can be done so that all the fixtures in the house get instant hot water?

One of my friends told me to check out a Lainge ACT909 which I did, is this a good option or will something else work better.

The house a full basement with the pipes in the ceiling exposed.

Suggestions and advise is appreciated.

[joed]

Insulate the pipe. Only minimal help.
Move the tankless closer to the fixture. You can't use a recirculating system on a tankless.

[Fischer]

What can be done so that all the fixtures in the house get instant hot water?

Suggestions and advise is appreciated.


You're kind of out of luck with instant hot water everywhere. The idea of tankless heater is to save the cost of heating the water in a large tank when it is not being used. The actual efficiency of a tankless is pretty close to a tank.

Pex piping helps by having a manifold that is correctly sized for the appliance which in turns limits the amount of water between the heater and that particular appliance. In other words a 3/8" pipe to a sink at the far end only has to have 3/8" of water. If you have a 3/4" pipe that feeds several branches before that appliance you have to heat that whole section of 3/4" to get water to the 3/8" line.

3.14159265 x R sq x L then divide by 231 if your in inches or X by 7.48 if the pipe is in feet . This will tell you how much water you would save by using a dedicated line.

[pushkins]

The Laing ACT909 web page says it is specifically for tankless H2o systems. It basically cycles to replace cooling water in the hot water line with water from the tankless at a preset temp.

[scuba_dave]

Where are you located?
I'm in MA & with current outside Temps the incoming water Temp is near freezing. That means the work a tankless has to do to raise the water temp is that much greater

I insulated my pipes (tank water heater) & it did help
The new tank water heater came with a 30" section of pipe insulation
Only the pipe near the WH was hot, so I didn't think it would have much effect. I checked it a few hours later & the copper pipe at the end of the 30" insulation was hot

I added another 4' piece & checked the next day. The pipe at the end of 6.5' of pipe insulation was now warm. So I insulated all of the hot water pipes. My basement is between 55-63, so it helps with heat loss, thus requiring less hot water

[AllanJ]

The Laing ACT909 web page says it is specifically for tankless H2o systems. It basically cycles to replace cooling water in the hot water line with water from the tankless at a preset temp.
I do not think it is wise to use a recirculating system with a tankless. This will force the tankless to cycle on and off more often all night long, likely shortening the life of its mechanical parts.

[joed]

One of the major selling points of a tankless is that you can put near where the water is needed thus eliminating the need for recirculation.

[pushkins]

I cannot see why cycling on every 30 minutes or so for 30 seconds at best (depending on the cycle temp. setting) would harm the unit. It would be no different than daily use in almost any home. I originally come from a place that tankless heaters are in far more than 60% of homes old and new, yes it is better/ideal to have the tankless unit close to it's main use but in retro fit situations in older homes this is sometimes far too expensive or impractical to achieve. The "then what do I do solution" is to install a recycling system to help alleviate the long hot water wait problem.
I read here all the time about objections to tankless systems for one reason or another, be it price or their ability to work well.
Price, yes they are pricey here in the U.S far more expensive than almost anywhere else and labor to have one installed if you can find a plumber who can/wants to do it, will most often run more than the unit itself.
As for the ability of the unit to service the average family's needs, the vast majority of Europe, Australasia, and Africa use tankless systems, I've been into rural villages in China on the Russian border where tankless systems supply families and have for years.
Price is the biggest issue here in he U.S and thus helping to drive fears, $1K for a reasonable unit, plus well upwards towards $1K installation all said and done, compare that to, $500 buys you a very good tank heater and maybe $200 installation (gas for gas models). They are advertised in all real estate sales pitches as " Hot water upgraded to a tankless system".

[Wgoodrich]

I suggest you install a second instant hot water heater. If you split the system with a heater at both ends of the house you have less plumbing to heat up to get the water to your appliance and allows you to install two smaller instant hot water heaters instead of one larger instant hot water heater. Cost factor and service size should be compatible to one big heater versus to smaller heaters.

Just my thoughts

Wg

[Yamaguy]

I am a Rinnai certified installer, and the best way to decrease the time it takes to get the hot water to the fixtures is to run a recirculating pump/line. One of the biggest misconceptions is that a tankless unit gives you instant hot water, but it doesn't it's continuos hot water. Water moves at 7fps~ IIRC and that does not change with a tankless unit. When you run a recirc. line in conjunction with a tankless unit it is best to have a small water heater to do the heating, not the tankless unit. If you look at the studies Rinnai has done the duty cycles of a unit with a pump are over 100 times higher over the life of the unit, and because of this the warranty is severely shorter.