Tankless Water Heater Installer

[singleshot]

 I have a Navien that works really well. Propane fired.  The purge before ignition " fan running" gets annoying but its installed where it should not have been.

[40-year-AZ-hunter]

I've thought about replacing a traditional natural gas water heater with tankless but the cost is a barrier. They advertise energy savings and instant hot water.

For those who have them, I have a couple questions. What percentage of energy savings would you see over a tradional tank that is well insulated with extra blankets? In terms of "instant hot water", is that really true? Doesn't the heated water still have to wait for the existing water in the line between the heater and the tap to be purged? For a tap at a distance from the heater, how is that different from a traditional system?

[Swivelhead]

1 hour ago, 40-year-AZ-hunter said:

I've thought about replacing a traditional natural gas water heater with tankless but the cost is a barrier. They advertise energy savings and instant hot water.

For those who have them, I have a couple questions. What percentage of energy savings would you see over a tradional tank that is well insulated with extra blankets? In terms of "instant hot water", is that really true? Doesn't the heated water still have to wait for the existing water in the line between the heater and the tap to be purged? For a tap at a distance from the heater, how is that different from a traditional system?

There are a number of issues with flash water heaters.   First being cost of install, a larger gas line or a more robust electrical circuit will be required over a traditional heater.  Flash heaters are expensive.  This issue alone can  eliminate any ROI over the life of a flash heater.  Next issue is how much hot water will a flash heater supply?  Depends on the temperature of the incoming water supply and the size of the flash heater.  If you get water from a well that is 50 degrees and the requirement is 115 degree hot water you may need a much larger heater than a home that has an 80 degree water supply.  The question to ask is how much temperature rise will my flash heater supply at a given flow rate.  Know the average temperature of your water supply.  With flash heaters, too much is better than not enough.  In terms of "instant hot water", there is none, tankless being the key word as there is no stored hot water.  As stated, the water lines in your home will still need to be purged of tepid water.

A true "whole house" electric flash heater  (6+ gpm with a 40 degree temp rise) will draw more than a 100 amps @ 240 vac.  If your local electric rate is time of day or demand sensitive, use during peak hours will be relatively expensive.  If at all possible, opt for a gas fired flash heater.

[elkster9]

Thank you to everyone who has responded,...I'm gathering quotes. From what I have found so far, the cost of the unit I am interested in "Navien NPE240a2" residential model is between $4250-$4800 installed (rates vary based on different companies)

[eddielasvegas]

1 hour ago, elkster9 said:

Thank you to everyone who has responded,...I'm gathering quotes. From what I have found so far, the cost of the unit I am interested in "Navien NPE240a2" residential model is between $4250-$4800 installed (rates vary based on different companies)

Wow!  5 grand for this tankless system.

If you're doing this to save money over a 40/50 gal. tank system, you will never do it at that cost.

If, OTOH, you have other reasons, then good luck and keep us posted.

 

Eddie

 

P.S. Our 50 gal. gas HW heater needed to be replaced about 10 years ago so I researched a tankless system.  That info revealed what Swivelhead stated above....that are many reasons to do this upgrade (if you want to call it that), but doing it to save money ain't one of them.

[Swivelhead]

2 hours ago, elkster9 said:

Thank you to everyone who has responded,...I'm gathering quotes. From what I have found so far, the cost of the unit I am interested in "Navien NPE240a2" residential model is between $4250-$4800 installed (rates vary based on different companies)

Another consideration is water quality.  I strongly recommend a water softener.   Hard water will substantially increase the maintenance cycle on a flash heater. Also consider a sediment style filter on the outlet of the softener.  When the softener resin bed fails (which it will eventually) copious amounts of resin will distribute throughout the piping in the house.  A real pain to rectify.  In my opinion, a retrofit is too much money the ROI is not good.  New construction, relocation, etc. may favor a tankless system.  Good luck with your project.