39.0 EcoSmart 36kw on demand hot water heater install
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- Опубликовано: 19 май 2019
- Lots of jobs are dependent on upstream jobs. In this case, I needed some nice warm water so I could get stucco done in the bedrooms over the winter... So this video is about hooking up our EcoSmart 36kw on demand hot water heater to our QO breaker panel and running a temporary water line to the bedrooms.
This is all part of our earth sheltered home building project. You can learn more at our website (www.homeintheearth.com) or at HomeintheEarth/ 
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Best install vid i have seen on this unit. And I’ve seen a few. Thanks and well done!!
easily one of the most informative installs I have watched thank you!
you should alternate sides of the breaker panel for each breaker so you are not pulling all of the power from one leg.
Always enjoy an update! Keep up the awesome work. Looking forward to the next one!
Thanks for explaining the electric connection.....
Wow that was easy. Cool to see the progress.
According to the installation manual, a separate ground conductor for each incoming circuit is required.
Yea, its easy for them to say that, but they would be seriously over sizing things. The 4 grounding wires would all be screwed to the same little bus bar and no current flows thru them during normal operation. If there ever was a short, the current would flow back thru that wire for a tiny fraction of a second before the breaker would trip. Even if all 4 circuits shorted at once (incredibly unlikely) with full amps, one 8 gage wire would be more than enough to carry the load for such a short time.
Have you installed one of these? Honestly, I was doubtful that I could have fit 3 more 8 gauge wires thru the knockout they gave me. I definitely couldn't have fit it thru the conduit.
Your voice is sooo soothing 😅
Some places don't have enough room in a panel for double breakers. Sometimes you gotta run a sub panel off the main just for this water heater.
Yea, that 4 breaker requirement really makes this difficult to add to existing construction. Most houses just can't handle the amps required, even with a sub panel.
Good video Keep it up :-)
Interesting, how are your electrical bills since then? I'm thinking of getting Retex-36 for a similar setup with a longer runway. Even at 70% derating, the code-allowed current would be over 150 amp: 38.5 x 4 = 154. This particular 36kw model is listed for a maximum draw of 150 amp, so 1" conduit should be fine. That's what they mean by "the 4 sets of #8 wire" statement in the manual. Not clear though why THHN/conduit option was selected in this temporary non-wet setup, instead of just 4 sets of Romex 8/2? Another minor potential issue may be a single #10 ground wire, kinda weak for the possible flow. A thicker single wire would probably be safer. The unit's ground bar has 4 slots with Romex in mind.
Honestly, heating with electrical is one of the decisions I am most nervous about. However, I was also concerned about the idea of burning natural gas in such a well sealed house. I also considered geothermal, but the cost was just too high to ever pay its self off. In the end, it was the availability and low cost of the install that tipped me toward electrical and I am still hoping I don't regret it. Once I am actually living there, I will be able to evaluate and compare the costs more clearly.
That one winter when I was shooting hot water on to the stucco walls ended up adding to the electrical bill. I forgot what the numbers were, but it was a noticeable bump over simply running the lights and power tools.
Nice video. Question though. Do you know on the 36 KW unit, if it would run with only the first two circuits connected, so it could be run as 18 KW, but have the capacity be used as 27 or 36 at a later time?
Yes, for sure. You can hook up just the first couple circuits and it will work just like an 18kw unit would work. Keep the flow rate down and it doesn't touch the 3rd or 4th circuits even if they are hooked up. But if you exceed that flow rate, you will see that you don't get enough heating, just as you would with an 18KW unit.
Just a heads up, because you put 8 current carrying conductors in that Smurf tube, you must derate all to 70%. 8ga thhn is rated for 55amps, 55*.70=38.5. So that 8 ga wire is only rated for 38.5 amps. You can get around this by running a second conduit and splitting it up. 4-6 current carrying conductors derates to 80% or 44amps on 8ga thhn. Also, reidentification of conductors smaller than 4awg is not permitted. You could run a 10awg equipment earth conductor, but it must be green or green with yellow stripe. Most home centers and hardware stores sell wire by the foot, so you can avoid having to buy a spool
The unit came with instructions saying to use the 8 gauge wire with the 40 AMP breakers (check the video at 0:43). Are you saying that the ENT conduit is the problem? The inspector told me (and I found it in a chart) that I was allowed nine of the 8 gauge wires in my 1 inch ENT conduit. That was perfect for my situation. Actually, the unit itself came pre-punched with a hole for the 1 inch conduit, so that was clearly what was intended. Not sure if it was officially passed in my last electrical inspection, but I think the guy did look at it and didn't say anything.
@@SimonHomeintheEarth Its not a problem with ENT, but rather a problem with current carrying conductors in ANY conduit. If you refer to NEC Table 310.15(b)(3)(a) it outlines the derating. The way is is written, you could have 8 14ga current carrying conductors in a 6 inch conduit and would have to derate. The conduit size is fine, With 8 current carrying conductors of 8ga size and 1 equipment ground of 8ga size, you are looking at 38.5% fill in 1 inch conduit. The reason for derating is heat, ALL current carrying conductors generate some level of heat while current is being passed through them. You can run another 1 inch or 3/4 inch conduit and split it. If you don't have a copy of the NEC rules in effect in your location let me know, and I'll arrange to get you a copy.
@@coshtor I agree with Clayton. Good catch. They probably anticipated the use of NM cable. Don Witt, PE
@@azdonw I'm thinking they anticipated nm, or a pull box and nipple below. Simon, a nipple (conduit less than 18") is exempt from derating.
@@coshtor Thanks for the info. I have the internet, so no problem finding the NEC tables. So, you are saying I should separate it into multiple conduits and then run them all into a box and then feed it from a box into the unit thru a shorter piece of conduit? At least the cost of that change won't be too much of a problem.
interesting choice, I think I favor the tank based heatpump based heaters.
any particular reason for not going with one of those?
I was avoiding tank heaters because they waste energy storing heat all day. The heat pump ones are more efficient, but the cost for those is about 4x what I paid. We will see how it goes. If the costs to operate the on demand one are too high (in reality as opposed to what the manufactures claim) perhaps I'll try out one of those heat pumps in series with it.
One other thought on this that I did consider at the time... The heat pump sucks heat out of the air to put it into the water. I plan to use that hot water to heat the rooms, so during the winter, it would be like plugging an extension chord back into its self.
@@SimonHomeintheEarth actually the idea is to extract heat from outside the house, not internal to it :)
ultimately its always more efficient to move heat (from outside to inside or vice versa) then to generate it. so I'm a big fan from an efficiency standpoint (and longterm costs)
Great video! Saw this on their website: 300 amp household service recommended. Mine is 200 amp. Do you think 200amp is enough?
most modern houses are designed with 200amps service , you can request a 400amp but that’s mostly for business
It depends how much of your panel is already in use. There are also rules for allowing for excess, etc. You would probably need to upgrade. If you can get natural gas, I'd suggest you go with one of those instead.
Did you crimp a terminal onto your 8 gauge wire or just strip them and insert them into the water heater terminal block?
No terminal required. The water heater was designed to take the wires directly and then had a screw to hold them mechanically.
Can you add a recirc valve or pump to get hot water faster at the faucet?
Yes
That's the first time I've seen a panel filled with blue flexible ENT conduit, no NMD in your home?
Nope, no NMD. ENT is readily available in stores here and is the only flexible conduit rated for being encased in concrete (that I know of). Is there any advantage to using NMD over ENT? Or is NMD just something you are more familiar with?
Buen día amigo cuánto se cobra por la instalación de un calentador así gracias espero la respuesta
I don't know. It only takes a few hours. Talk to a local HVAC guy.
Seems ridiculously simple. What were your hot water costs per month on your electric bill? Anyway to isolate and figure out?
That was the worst part. Electric is not the cheap way to heat water. Maybe I should have used natural gas, but that install was expensive, I didn't think I would need much and I didn't like the idea of combustion in my underground home. Also, the cost of natural gas has doubled in the past couple years, so maybe it wouldn't have been cheaper.
I ended up adding a solar hot water system and hooking it up to the front end so the water now is pretty much full temp going into this heater now (the solar actually gets it hotter and I used a thermal mixing valve to add in some cold water). Anyway, on sunny days (and the night and morning after) hardly turns on at all now.
is it better to have the tank the close to the breaker?
The longer the cable, the more voltage drop along it. But you also have certain minimums. It is also important to have the hot water as close to the final taps as possible...
Cool
Curious why didn't you use an on demand gas heater?
No gas supply ;) But also, I am not sure that combustion is a great idea in a very well sealed underground house.
I was just wondering if you could leave one of the heating elements unwired and this unit still work properly I don’t want to under size my house would rather over size and I thought I’d I went with the 36 and didn’t need it if I would just leave one breaker off if it would still work correctly if anyone could answer thanks
Yea, I have learned a lot about these things using them for the past couple years. The first heating element is required. You can leave the rest unwired (or turn off the breakers) if you wanted and it would still work just as well as the smaller units.
When I installed it, I thought it measured the incoming temp and then would increase the energy flowing thru the 4 resistors until the outlet temp reached the target (standard way that most control systems work). But I am now certain that it doesn't work that way. Instead, what it does is measure the incoming temp and then calculate how much many amps are needed in the first resistor. Most of the time, that is all it uses. If you are running multiple showers or something like that and the flow rate goes up, then its calculation finds that it needs the second resistor, etc. If it uses the second sensor, that is just a check on its programming.
How do I know? Well the first resistor burned out on one of my units. It was the darndest thing because we would have no hot water if we only ran one tap, but if we ran more, we would get "warm" water. Basically, the algorithm thought it was dumping energy into that first resistor. When the flow rate went up, it also turned on the second one. Since the second one was working, we actually got some warm water out. I ended up moving the 4th one into the first slot and things were fine while I could go online and order another element. The 4th element looked totally unused. The 3rd looked rarely used, etc. all the way back to the first that looked really worn out. Pictures are posted on our Facebook channel.
@@SimonHomeintheEarth thanks that’s what I was looking for I think I’m going to go with a 27kw and give it a try hope I don’t regret getting the 36
I didn’t see a ground wire connected in the main panel
2:27, you can see a black wire with green tape on it. I just didn't bother to buy green wire because it is cheaper to buy it by the 50 ft roll.
yikes! NEVER POWER before flowing water through!
How many ground wire you connected all 4 or just 1
Please respond i appreciate
Thank you.
Just 1 , from main panel to water tank cold side
Look at the fken thing can u can see
Yea, just one. Current doesn't flow thru the ground wire during regular use. If it does go thru the ground wire, it is just for a tiny fraction of a second to trip the breaker if something goes wrong, so the wire doesn't need to carry the working load.
The EcoSmart manual calls for a separate ground wire per circuit.
@@sghantous Yes, the manual calls for much much more capacity than would be needed in reality. Think about it this way... My entire breaker panel has only got one little ground wire to ground the whole thing. Even if I ran 4 wires from the unit to the panel, there would still only be one wire from the panel to the ground. I won't be running current thru the ground wire to the ground like that anyway, I am only using it to catch a fault and trip the breaker. Current would only flow for an incredibly brief time. As an engineer who can do the math, I have absolutely no worries about running the full amps thru that wire for much longer than it would need, and I also know that such a scenario is so incredibly improbable that I have a much greater chance of winning the lottery.
Wow. 36kw! How much power do you expect to use continously (middled out on off cycles) for heating in winter?
I don't know yet. It may be a bit life changing once I calculate costs per second of shower time ;)
The manufacturers claim it is efficient and it has an Energy Star rating, but that is probably in comparison to an electric hot water tank, which is just the worst possible situation.
How many man hours were put into this project
I think it was just a few hours (all within one morning). Brody arrived at 10:00 or 11:00, just in time to help me run the tube to the garage and test the hot water.
@@SimonHomeintheEarth Very Interesting
Does it need a ground cable?
Yes, and it has one.
@@SimonHomeintheEarth lol fuckkk a year too late thanks 🤣🤣🤣