Undersink Tankless Water Heaters Unavailable, Why?

[Lost_in_the_HTTP]

Amazon.com

All similar ones are the same, unavailable, out of stock. Why?

Some kind of recall?

 

[allisolm]

Could be your location. Shows as available in FL. VA, and TX.

 

[jmagg]

available in ny

 

[Greenman]

Available in MS.
That thing needs a 35 amp single pole breaker. I had no idea they made such a thing.

 

[waffleironhead]

When i worked retail, i sold a few of the rheem brand point of use. So, a decent name brand, not some chinese crap brand.
Every single one was returned. Why? Because our ground water temp is so low in northern wi that these things dont work here.
So i caution you to check the temp rise you are looking to acheive, because these little units are not rated for cold climates.

 

[Greenman]

When i worked retail, i sold a few of the rheem brand point of use. So, a decent name brand, not some chinese crap brand.
Every single one was returned. Why? Because our ground water temp is so low in northern wi that these things dont work here.
So i caution you to check the temp rise you are looking to acheive, because these little units are not rated for cold climates.

I never thought about that, good call,

 

[[DHT]Osiris]

When i worked retail, i sold a few of the rheem brand point of use. So, a decent name brand, not some chinese crap brand.
Every single one was returned. Why? Because our ground water temp is so low in northern wi that these things dont work here.
So i caution you to check the temp rise you are looking to acheive, because these little units are not rated for cold climates.

Couldn't you just turn up the temperature on the unit to account for the groundwater temp difference? There's a pretty big delta between the hottest groundwater and coldest in the US but I imagine it's designed for somewhere in the middle, couldn't you just crank it for the northern climes?

 

[waffleironhead]

Its really just a function of how much power the unit is rated for. These little units heating elements are so small and use so little power(relatively) they can only handle so much temp rise. They also only kick in at say .25 gallons of flow rate. So as designed they can only handle so much temp rise at so much flow rate. If you could overide the flow rate kick on, im sure you could heat enough, but then flow would be at a trickle.
Either need to buy a bigger unit with more heating elements, or run 2 little ones in series.

 

[Lost_in_the_HTTP]

I can't imagine they would be geo-blocked.

Also looking at a more typical 5 gallon tank model that would sit under the sink. The ones I've seen only have a 1500 watt element and would easily fill a bathroom sink for a quick splash when needed.

My 30+ year old 40 gallon tank has a 5000 watt element and I can almost hear the electric meter groaning when it cycles.

 

[jmagg]

I can't imagine they would be geo-blocked.

Also looking at a more typical 5 gallon tank model that would sit under the sink. The ones I've seen only have a 1500 watt element and would easily fill a bathroom sink for a quick splash when needed.

My 30+ year old 40 gallon tank has a 5000 watt element and I can almost hear the electric meter groaning when it cycles.

Have you ventured outside of Amazon for the product?

 

[WelshBloke]

Couldn't you just turn up the temperature on the unit to account for the groundwater temp difference? There's a pretty big delta between the hottest groundwater and coldest in the US but I imagine it's designed for somewhere in the middle, couldn't you just crank it for the northern climes?

Use two in series! 😆

 

[[DHT]Osiris]

Use two in series! 😆

That should actually work fine, just set the first in series to a lower temp so it doesn't overheat any of the initial components of the first. Annoying increase in maint and costs though. Be more efficient to drop a few kg of uranium in your well.

 

[Micrornd]

All electric "instant" water heaters depend on a flow sensor to turn the unit "on and off", and thus require a minimum flow to turn on the heating element. They also have a temperature sensor to regulate the heating element to produce the desired temperature (the temperature may be adjustable or not, depending on the unit.

Follow please - The minimum flow required vs the final temperature required determines how long the heating element (turned on) needs to stay in contact with the water (pipe).
If the heating element is too small (wattage) the water may not stay in contact long enough to be heated to the desired temperature and reducing the flow rate, in an attempt to increase the "heat contact" time, may then have the flow fall below the minimum that the flow sensor requires to "turn on".
All this determines the advertised flow rate, temperature rise, and wattage requirement of an "instant" water heater. (the principles are the same for "gas" units).
All manufacturers have charts for all their models showing flow rates vs wattage vs temperature rise and that's the best place to start.
Get a list of manufacturers available to you (online or local) and check their websites for the models available to find what you really need.
(And if they don't have a website, don't think of buying them, while water and electricity don't mix, if done improperly they can with deadly results)

I have purchased more than a dozen from the Stiebel Eltron line (their units have various names (Stiebel Eltron, AquaPower, Tempra, etc.) depending where they are sold - Lowes, Home Depot, supply houses, etc.) and can vouch for their build quality and accuracy of their technical data.

Electric Hot Water Heater | On Demand Heating | Stiebel Eltron USA

Tankless water heaters can save you money and energy! Innovative, efficient water heating products have always been the cornerstone of Stiebel Eltron.

www.stiebel-eltron-usa.com

BTW - 2 in a row (of the same size) very rarely works because of the flowrates involved and 2 different sizes inline is just a waste of money, when you can buy 1 of the correct size.
Hope that helps you.