Having a tankless heater doesn't change the fact that there's volume in the pipes between the heater and point of use. That's the same as for a tanked heater. Volume divided by flow equals how long you have to wait.

The further the point of use is from the heater, the longer you have to wait. One way of mitigating is to use home-run piping, which PEX pipe accommodates well. You run smaller-diameter pipes from a common manifold to each outlet. Then you get hot water quicker, but you still have to wait at each outlet. For example, with a common pipe, the sink by the shower gets hot water fast after you've showered. With home-runs, you get hot water faster at the shower, but have to wait for it at the sink, too.

One advantage of the tankless is its small footprint and the ability to mount outside (and save the cost of the expensive vent piping required). This would allow you to put it closer to the point of use.

You might look into recirculation (which is more complicated w/ tankless than a tank heater) or a hybrid system. There was an article in Fine Homebuilding w/in the past year about putting in a small, electric tank heater (10 gal or so) downstream of a tankless to provide buffering and quicker delivery of hot water.

Good luck. Sounds as though you were misinformed or confused about what a tankless would/wouldn't do.

The time it takes for the hot water to get to your faucets or shower is related to the distance the water has to travel from the hot water source to the sink and the diameter of the hot water building supply pipe (typically 3/4 inch) as well as the feeder pipe to the sink (typically 1/2 inch).

A 3/4 inch pipe holds about 8 ounces of water for every 3 feet of pipe. So if your tank (or tankless) unit is 90 feet away from a faucet, you would have to push out about 1.8 gallons of cold water (plus whatever water is in the feeder pipe, a 6 foot section of 1/2 inch pipe holds about 8 ounces of water) before the hot flows. A typical sink faucet will run at 1.5 gallons per minute maximum flow rate - so you are looking at over 1 minute to get hot water in this scenario.

With tankless units, there is also a small delay between the time the unit senses water flowing through it (which triggers it to fire) and the time the unit heats the water up to the set temperature.

There are 3 ways you can eliminate the long delay. The first is to put a hot water source (tank or tankless unit) closer to the sinks that are far away from the current source. The second way is to use point of use hot water generators under key sinks that you use. These POU units are very small tanks or tankless units designed to service just once sink. The last method is to install a recirculating loop where you constantly circulate hot water through the hot water building supply.

I have a Rinnai tankless system that we installed in the basement directly below the master bathroom. From the time I turn on a shower or sink, hot water is flowing within 10 seconds. That was the good news.

The bad news was that the kitchen sink and 3 other sinks that we use often are over 120 feet away from the Rinnai tankless units. Just before we finished the house, we discovered that it was taking several minutes to get hot water at the kitchen sink - and that was unacceptable to us. I wound up installing a recirculting loop. This was not the way I would have preferred to do it, but space and venting in the basement on that side of the house was an issue.

You could just live with the delay you have - 1 minute isn't that bad. If you decide to fix the delay, I recommend posting some details on the plumbing forum and seeking advice on how best to correct.

4-ways

Just get one of these:

The Ultimate in Energy Efficiency with Hi-Tech Comfort
Endless Hot Water Supply
Ultra Condensing 98% Efficiency
Built-in Circulation System ("A" model only)
-For internal circ to allow minimal hot water draw requirements or built-in external circ
ECO Navien Technology
Extended Lifecycle
PVC Venting & Easy Installation
Optimal and Stable Operation
Leak Detector
Air Intake Filter
Space Saving

Here is a link that might be useful: Navien America