Tankless Electric Water Heater
14.6 at 240
14.6 kW, with 14.6 at 240V - Marey Eco150 - manual explicitly says 6 ga wire but 70A breaker [1]. Manual [2]. Plumbing code defines hot water as 110F. Rise at 2/1.5 GPM is 51F/68F. Compare to the 13 kW Rheem-like systems below [3] with 44F/59F rise at 2 GPM/1 GPM.
- Avg groundwater temp is 52F in Maysville MO. [4]
- 13kW gets us to 96F/111F at 2 GPM/1 GPM, and 14.6kW gets us to 103F/120F
13kW
- $329 Richmond 6 ga menards ETL UL side [5] [6]
- $290 Rheem side outlet 73%-ETL UL 6/2 wire [7]
- $200 Ecosmart 11 - 13 kW 6 ga side outlets. 71% good review Amazon's Choice [8]
- $230 EEmax good review 74%, UL ETL 6 ga - [9]. Home Depot has it.
- 12 kW bottom outlets UL ETL. Bad reviews 48%. needs GFCI Bosch [10] [11]
- Marey 14.5 [12]
- Eemax Pro 13240 [13]
- Atmor bottom inlet with drain? [AT-S901-13] [14]. Manual for drain and outlet?
- Ariston visible mount bottom [15]
- Lolicute bottom 6/2 [16]
- Funchic [17]
13kW 4 ga
- Atmor - 4 ga [18] + [19]]
- Ariston bottom outlet 13kW Menards 4ga [20]
- Black and Decker Bottom 13 kW but says 4/2 [21]
11kW
No Tank
Typically come in the 3kW variety, but more advanced ones are 1.8kW. Otherwise, 1.5kW are mini-tank, not true tankless.
- 13 kW 6/2 wire - RTEX-13 - pro series [24]
- 13 kW requires 4/2 wire [25]
- 1.5 GPM 7 kw 30A 240 2-pole breaker [26]
- 9 kW [27]. Seems to have logic to heat as needed.
- 6kw - [28]. Seems to have proper heater logic according to a review.
- 1.8kW electric on-demand water heater - $159 - comes with aerator, 0.21 gpm activated, limited to 0.32 gpm. [29]. 39F temp rise at 0.32 gpm. [30]
- Cheapo point-of-use on-demand electric - 3kW - $68 [31]
- 3kW on Ebay, $60 - [32]
- 2.6kW - 60F rise at 1GPM - on the shower itself - [33]
Mini Tank
About 1.5 kW - worst of 2 worlds - don't have enough continuous hot water, and waste energy. You can tell by their larger size than true tankless.
Power Draw
- Great point from review from a wise electrician - 'I just wanted to clarify a few points in respect to wattage and breaker size...
The element is rated at 1440 watts (at 120 volt), As stated this would be considered a continuous load per NEC 424.3. So, 1440 watts x 125% = 1800 watts 1800w/120v = 15 amp So it seems like 15 amp would be correct? NOT SO FAST. Since the element is a resistive load the wattage rating of the element increases as the voltage increases. Any source voltage greater than 120 volt will therefore put the load on the circuit above the 15 amp rating. Depending on your geographic location there is a very good chance the power company is supplying >120 volts. This may not jive with what you have heard, but after having this discussion with many journeyman electricians over the past 40+ years I've made a point to teach my apprentices the math behind it. see less By LifeTastesGood on September 20, 2019' - ref
Links
- Tankless Water Heater
- Hot Water - will water be warm enough to use?
