Does anyone want to recommend a good electric water heater?

[mikefamig]

I just noticed something interesting. The expensive Marathon has a 6 year parts warranty and the cheaper models have 9. Maybe they used cheaper parts in the Marathon to offset the cost of the more expensive plastic tank and construction.
 
Mike.

 

[RAL]

I've been reading and I'm liking the Rheem Marathon because of the light weight, availability at HD and absence or anode rods. I have no exterior access to my basement and have to get this heater through the family room and down a flight of stairs to get into there so light weight is good and the lack of anodes means that maintenance consists of just draining the tank once in a while. It uses about 4700 kwh/year which is as good as most standard electric heaters and 400 less than what I have installed now.
 
http://www.homedepot.com/p/Marathon-50-Gal-Tall-4500-Watt-Lifetime-Electric-Water-Heater-MR50245/100209103#specifications
 
or the Rheem Performance Platinum
 
http://www.homedepot.com/p/Rheem-Performance-Platinum-50-gal-Medium-12-Year-5500-5500-Watt-Elements-Electric-Water-Heater-with-LCD-Display-XE50M12EC55U0/204318353
 
Comments?

 
 
My choice would be the Marathon water heater over the Rheem with the traditional metal tank.  I prefer the idea of a plastic tank and no anode. The Rheem also has the added complexity of the electronic control panel.  Although the Marathon costs more up front, I figure replacing a metal tank model in 10-12 years will cost you more in the long run.  But you've had a pretty good run with your old water heater, so that's something to consider, too as well as how long you plan on living in your current house.

 

[RAL]

I just noticed something interesting. The expensive Marathon has a 6 year parts warranty and the cheaper models have 9. Maybe they used cheaper parts in the Marathon to offset the cost of the more expensive plastic tank and construction.
 
Mike.

 
Water heater parts warranty coverage periods are puzzling.  
 
I guess I would worry less about the Marathon since it doesn't have a whole lot of parts that are likely to fail - primarily the heating elements and thermostats.  Neither of them are terribly expensive to replace and aren't difficult to do yourself.  On the other hand the Rheem has the electronic controls, which would concern me more when it comes to the cost of replacement parts.

 

[mikefamig]

Now I found that I can get a $400 rebate from Connecticut if I buy a hybrid heater. That would make the Geospring hybrid cost $599 at Lowes. I still don't want an air conditioner in my basement but I thought that someone out there may like to know. New York has an even larger $500 incentive.
 
Mike.

 

[Madcodger]

I am replacing my almost 14 year old water heater this weekend just as a precaution (ugly when they go on their own, sometimes) with a Geospring so will be able to report back on noise, cold exhaust, etc. Will be installed in the basement, 1/2 of which is finished and used as an office every day, with the other half utility / storage.

The one thing I'm not seeing in this thread (which surprised the heck out of me given that this is CT) is any discussion of either automation or monitoring of the Geospring. Given that I have an Elk M1G, ISY 994 with Zigbee, and Homeseer - any ideas / suggestions?

 

[mikefamig]

I am replacing my almost 14 year old water heater this weekend just as a precaution (ugly when they go on their own, sometimes) with a Geospring so will be able to report back on noise, cold exhaust, etc. Will be installed in the basement, 1/2 of which is finished and used as an office every day, with the other half utility / storage. The one thing I'm not seeing in this thread (which surprised the heck out of me given that this is CT) is any discussion of either automation or monitoring of the Geospring. Given that I have an Elk M1G, ISY 994 with Zigbee, and Homeseer - any ideas / suggestions?

Please post back what you learn. Before you jump into it I suggest reading the installation manual entirely. A heat pump requires a minimum amount of cubic feet of space to work properly. If you put it in a closet it will not get enough air circulation to make heat.
 
As for automating it I think that it is best to leave the heat pump hybrid water heaters powered at all times. When in heat pump mode they run on less electricity but they take a long time to heat the water so they run long. I don't think that it's a good idea to turn it on and off. THe conventional electric heater can recover pretty quickly so you can turn it off whenyou go to work and then back on an hour before you return and it will recover temp.
 
Mike.

 

[ricklearned]

On another thread I posted a similar question about automating a geospring. I am doing what Mikefamig cautions against. I also have concerns about turning it off snd on, but found no better alternative. I use a OmniIIe to close a 30 amp relay. The water heater runs only from midnite to 6am when my TOU rates are the lowest. I also only run it in heat pump mode. It is also off when my alarm is in away mode
Here is the link to my other post:
http://cocoontech.com/forums/index.php?/topic/27040-Geospring-water-heater-control.#entry218789

 

[mikefamig]

On another thread I posted a similar question about automating a geospring. I am doing what Mikefamig cautions against. I also have concerns about turning it off snd on, but found no better alternative. I use a OmniIIe to close a 30 amp relay. The water heater runs only from midnite to 6am when my TOU rates are the lowest. I also only run it in heat pump mode. It is also off when my alarm is in away mode Here is the link to my other post: http://cocoontech.com/forums/index.php?/topic/27040-Geospring-water-heater-control.#entry218789

 
I'm no expert on the subject for sure. My fear is that by turning it off for a lenght of time the water in the tank will get cool. Then when it starts back up it may use the electric heating elements to recover quickly and defeat the purpose of teh heat pump. Can you force it to run heat pump only and if you do will the heater be able to recover in a reasonable amount of time?
 
Mike.

 

[RAL]

You can run the water heater in heat pump-only (efficiency) mode, hybrid mode, where it uses the heat pump and resistance heating coils together to recover more quickly when necessary, or in resistance-only mode.
 
In efficiency mode, it does take longer to recover than in hybrid mode. I would figure 1.5 to 2x as long.
 
I don't think the cooling of the tank would be a concern in most cases, unless perhaps you normally use a large percentage of the water heater's capacity while it is off. 

 

[ricklearned]

The only thing I was worried about was the electronics booting up once a day vs. two or three times in a normal year. Also, I have heard there are mechanical issues with a vacuum pump/compressor cycling too quickly. My application is on for six hours and off for several days when the alarm is on.

My preferred scenerio would to be able to set temp range for various times of the day. That way i could have a minimum setpoint during the day so at least we would have warm water. I would use a higher setpoint during my super low rate period to insure that most of the kWh consumption occurred then.That way I could avoid a scenerio whereby we had to take cold showers in the late afternoon after doing several loads of laundry and running the diswasher.

 

[RAL]

The only thing I was worried about was the electronics booting up once a day vs. two or three times in a normal year. Also, I have heard there are mechanical issues with a vacuum pump/compressor cycling too quickly. My application is on for six hours and off for several days when the alarm is on. My preferred scenerio would to be able to set temp range for various times of the day. That way i could have a minimum setpoint during the day so at least we would have warm water. I would use a higher setpoint during my super low rate period to insure that most of the kWh consumption occurred then.That way I could avoid a scenerio whereby we had to take cold showers in the late afternoon after doing several loads of laundry and running the diswasher.

 
I don't think you need to worry about short cycling the compressor.  They all tend to have pressure cut-outs that will turn the compressor off if the pressure in the refrigerant lines is too high.  Even basic window air conditioners have that built in.
 
The Geospring water heater has an Appliance Control Module (ACM) interface (which is believe is a CEA-2045 interface) that allows the water heater to communicate with a smart electric meter to adjust the energy consumption of the water heater.   From what I have read, the electric meter tells the water heater whether the electric cost is low, medium, high or critical, and the Geospring adjusts its operating mode accordingly.
 
During high rate periods, the Geospring reduces the set point temperature to 110 degrees and operates only in heat pump mode.  During critical periods, it reduces the temperature to 100 degrees, also operating only in heat pump mode if the water temperature falls below the lowered set point.
 
From what I can tell, the interface does not allow more basic control, such as adjusting the water temperature to any value or directly controlling the operating mode.  But perhaps there is a hidden diagnostic mode that would allow that.
 
Still, if you are up to hacking the ACM interface, you could probably just use the "high" and "critical" rate modes to accomplish what you want.

 

[ricklearned]

I couldn't even find an ACM interface anywhere when I looked a few months ago. I do have a smart meter, but I think it speaks zigbee and or some powerline language.

 

[RAL]

This paper gives a high level overview of the how the GE control system works.
 
GE has a control module that they call Nucleus that uses Zigbee to talk to a smart meter, as well as the ACM units on the individual appliances.  The ACM then uses a hardwired interface to talk to the appliance.  This is what I believe may be CEA 2045, which is a recent industry standard.  But I could be wrong about GE using that since I'm just reading between the lines on various articles about their smart appliances.
 
The documentation on what the ACM interface is is well hidden.  I've been looking for details for quite some time.
 
Today, I came across this recently announced interface board, which looks like it would make controlling the water heater much easier.  The Geospring is included in the list of supported devices.
 
http://makezine.com/2014/09/19/ge-launches-an-interface-board-to-let-you-to-hack-their-appliances/
 
https://firstbuild.com/greenbean/
 
The examples here make it look like you can indeed control the setpoint temperature.

 

[ricklearned]

Thanks, I will look at that some more. I did buy the greenbean, but haven't made the shlep with my laptop to the garage to test it.
 
Update: I did connect it and found that it uses command level queries to do anything. I am not up to the steep learning curve for that at this moment.
 
I did finally find where I can purchase the Appliance Communication Module and I am going to try that route. Here is the link:
 
https://www.geapplianceparts.com/store/parts/spec/DRM1E300T0
 
It costs $49 and I found an app that should work on my Android.

 

[Madcodger]

I installed the Geospring this weekend, and am very pleased thus far. Very easy installation with very good instructions. Ran it the first day in hybrid mode just to see what happened, and it made enough hot water for a nice shower within just a few minutes (exactly like a regular HW tank). Been in heat pump only mode since Sunday and with just two of us here it hardly breaks a sweat. My wife reports that after one load of laundry on sanitize setting, a long shower each, and running the dishwasher on "turbo" mode, the sink water was less hot than normal but usable, so that's a pretty good test for heat pump only, and close to our max use in a day. We'll switch to hybrid mode when guests arrive over Christmas for a few days, and see if that's sufficient (65 gallons first hour recovery). If I had a larger family (especially teens) I would consider an 80 gallon, which I think they make.

No louder than a typical small dehumidifier, and the exhaust air is not very cold (feels like a small fan moving room temp air) nor coming out at anything more than velocity of a small fan running on low-med. I cannot hear the unit from around the corner in the basement, and my wife's desk is on the opposite wall from the unit, with a ventilation grid in the wall. No complaints!

No idea as to energy savings yet but will report back as bills come in. Went from 80 gallon tank previous owners had to a 50, so immediate savings there. But expect this little jewel to pay for itself in under two years, easily. Surprisingly, GE based their stated figures based on running in hybrid mode with a 135F setting. We are running at 120F (the default setting from factory, and plenty hot) and heat pump only, so should save even more than the projected $352/year.

As for automation, a $20 interface is available for hackers. I will order in next week or so and post link. Must teach myself javascript to interface, which is planned for later this month as business slows down a bit. Plan to interface with ISY or Homeseer, and both track "on" time and allow us to set to hybrid mode from Insteon keypad (and remind us to turn that off when guests leave). More info in a few weeks...