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I recently moved into a condo unit in Washington, DC (2nd floor of 2 story building) and I'm looking to replace the 47-gal lowboy electric water heater that's from 2003. The problem is that there is no pan (we do have people that live below us) and, while there is a drain pipe, it's higher than the pan (see pictures below). I believe that the copper pipe connects the heater relief valve to the drain.

Also, there's no expansion tank.

The heater is in a hard to reach location in the kitchen closet, behind the washer/dryer unit. To access it, I'd have to remove the fridge from the kitchen, take off the closet door, and pull out the washer/dryer.

The tank is 31.5-32" tall and there's 19" of space above it. I'd likely have to get the exact same size replacement because the water lines coming in from the top aren't flexible. I'd ideally like a larger capacity tank because we don't get a lot of hot water with this one.

I've had 3 plumbers come in and all want to charge me between $1800-$2500 with a "play it by ear" mentality regarding the pan. Needless to say, that doesn't give me a warm and fuzzy feeling. I'd like to know exactly what is going to be done to address the pan issue because come time to sell down the road, it's important to me that the new heater will pass inspection.

Given the estimates, I'm tempted to try and do the job myself. But I need some guidance on how to address the drain being higher than the pan. One of the plumbers suggested trying to build up the floor underneath the water heater, but I don't know how feasible that is. Also, is an expansion tank necessary?

I'd really appreciate any advice on this matter. enter image description here enter image description here enter image description here enter image description here enter image description here enter image description here

Adding pictures of HVAC as it relates to the discussion in the comments: enter image description here enter image description here

And finally, a picture of my electric panel enter image description here

littleK
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  • The exact same size replacement might not be feasible due to efficiency regulations requiring thicker insulation. One the exact same size externally will necessarily have a smaller tank. The copper tubing isn't flexible of course, but would be cut and fit for a new tank anyway, so you'll end up using that height if you want the same capacity. – Tim B Jun 02 '17 at 14:53
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    How big is your condo? A 47 gallon tank should provide plenty of water for even a 3-4 BR, 2-2.5 BA house (I have a 50 gallon tank in a 4BR, 2.5BA). I suspect your current tank may be full of sediment, severely restricting its capacity. Replace it with a like sized one (or even a smaller one, depending on condo size, maybe a 40 gallon) and you probably won't have hot water issues anymore. – mmathis Jun 02 '17 at 14:56
  • Do you have any gas appliances? – mmathis Jun 02 '17 at 14:57
  • No gas, everything is electric. The condo is 1100 sq. ft. (2BR, 1BA). Any thoughts on the pan and drain situation? – littleK Jun 02 '17 at 15:14
  • How strong is your electric service? This has "tankless" written all over it. @mmathis "absolutely no gas in the building" is very common for condos. I am at a site which is the same, with a heat pump (on 20A breaker) interchanging with water from a service coolant loop. In summer that coolant goes through a cooling tower, in winter it is heated with gas in the boiler room. – Harper - Reinstate Monica Jun 02 '17 at 15:17
  • I would love to go tankless, but I've seen mixed reviews on electric ones. Also, the plumbers I've spoken with say they won't install due to cost of electric bill during the winter time as well as the hardness of DC water. But I'd imagine that hard water would effect tanks more? And given the mechanics of a tankless, I can't imagine it would be more energy than a tank? I have yet to test amps, but I'd have to expand the electric box. There's no more empty cartridges. – littleK Jun 02 '17 at 15:26
  • Is there any reason (code reqt or practical) for the drain to be that high off the floor? If not, you could cut it off say 4" above the floor, then put a new heater on a platform the same height as the drain so a pan could drain by gravity into the drain pipe. I assume the drain is plastic and so it could be cut off easily by a DIYer. If it is cast iron, it can still be cut off, but this would require a special cutter which one could rent. When you install a new tank you will cut the copper lines and you should connect the new heater with flexible lines with an insulating coupling. – Jim Stewart Jun 02 '17 at 15:41
  • Not sure if there's any justification behind the drain height, but I can ask other owners in the building about their setups. It appears to be plastic, so I think that cutting it would be a feasible option. What type of platform would you put the new heater on? – littleK Jun 02 '17 at 15:50
  • A central electrical resistance tankless heater would draw more current than you have available. Replacing the existing tank with a new one of the same type is going to be the only practical solution. The heat pump heater described by @Harper would heat water for much less electric power than resistance heat, but requires the extra water heat exchange loop to the roof. This must have been installed as new construction. I doubt you could do this as a replacement. Is this heat pump a tankless or a tank? What is the noise level when the compressor is on? – Jim Stewart Jun 02 '17 at 15:57
  • @Jim With "heat pumps" I was referring to our HVAC... but you raise an important question. What if his old water heater *is already* the heat pump exchange type? Probably not. – Harper - Reinstate Monica Jun 02 '17 at 16:01
  • Our HVAC is a heat hump, and it is positioned directly above the water heater. Not sure how I'd determine if the water heater is tied into it. – littleK Jun 02 '17 at 16:05
  • extra unexplained pipes. @littleK Tankless water heaters are awesome when idiots are not involved. Speccing correctly requires skill. It uses less electricity *overall* but **much more** in the moments of use, hence my interest in your electric service. What matters is the ampacity of your panel, not the spaces available (there are ways around "full".) – Harper - Reinstate Monica Jun 02 '17 at 16:06
  • How can I determine the ampacity of the panel? – littleK Jun 02 '17 at 16:08
  • @Harper, from my experience the existing heater here is a simple electric resistance heater. I don't think a heat pump water heater tank would work in this application: (1) insufficient vertical clearance (2) insufficient space for heat extraction (3) possibly noise generation unacceptable – Jim Stewart Jun 02 '17 at 16:18
  • I've added two pictures of the HVAC that sits above the heater in case it helps with this discussion. It's at least 15 years old. – littleK Jun 02 '17 at 16:27
  • @littleK there will be a breaker larger than the others, or, in the upper left corner. It will have a number on it, probably 100, 150, 225, something in that range. – Harper - Reinstate Monica Jun 02 '17 at 16:44
  • Added a pic of my electric panel as well. #1 & #3 is heat pump, and #2 & #4 is AC, and #6 is water heater. – littleK Jun 02 '17 at 16:45
  • A suitable platform could be built with a 2x4 frame with 3/4" plywood on top, which you can make (and should) even if you have a plumber install the heater. Plumbers as a group are not especially good carpenters and with a little planning you can make a really good platform. Find out if there are any code or other requirements on the height of the drain. It could be that the height must be above certain other drains in the house. If you can't cut it off or don't want to, just make the platform the height of the drain as it is, and get a water heater which will fit on it. – Jim Stewart Jun 02 '17 at 16:50
  • There are commercially available stands required in most jurisdictions for water heaters in basements and garages. Usually they elevate the heater 18" which is more than you need and could possibly be too high for the heater you would want. See http://www.homedepot.com/p/Eastman-21-in-D-x-21-25-in-W-x-18-in-H-Water-Heater-Stand-86278/205365245?cm_mmc=Shopping%7cTHD%7cG%7c0%7cG-VF-PLA-D26P-WaterHeaters%7c&gclid=Cj0KEQjwmcTJBRCYirao6oWPyMsBEiQA9hQPbiDWsmb9T-MBOR2J0DD-ydbBpLtM2W4MN-ZtzzQWHFwaAnls8P8HAQ&gclsrc=aw.ds – Jim Stewart Jun 02 '17 at 17:01
  • Hmmm. 1-3 is a double-stuffed 2-pole, 100?/30. The 100 can't possibly be the main breaker since it's too little to serve the two 2-pole 60s and two 2-pole 30s. Oversubscription is normal but not *this* much on the *big stuff*. 5-7 is baseboard heat? The main breaker is not there. This may be the time to consult with the building's superintendent – Harper - Reinstate Monica Jun 02 '17 at 17:01
  • Thanks @JimStewart. I'll look into building or purchasing a stand, as well as what is up to code. – littleK Jun 02 '17 at 17:14
  • @Harper, #5 is electric oven range and #7 is dishwasher. The master circuit breaker for each individual unit is in a separate utility closet located in the front of the building. Same goes for master water shut-off. This place used to be an old car garage, renovated in the 1970's. – littleK Jun 02 '17 at 17:14
  • Yea, 10&12 is Dryer & Washer. I'll see if I can get into the main utility closet to examine the main. – littleK Jun 02 '17 at 17:35
  • 5-7 are a 2-pole, can only be one thing, range then. 60A is generous. I see now, 1-3 is both your heat pump (30A) and auxiliary heat (100A). The upshot of all this is your service is quite impressive and could likely support on demand heater(s) even right at point of use (i.e. Near instant). Next question is if on demand can play well with the hard water. Relevant advantage here is an on-demand takes much less space. – Harper - Reinstate Monica Jun 02 '17 at 17:46
  • Home Depot has a 24" square stand which you would probably need for a squat form electric tank, but it is 18" high which might be too high for your application, but maybe not. You should not cut off the drain until you find out for sure that it does not have to be say taller than the toilet bowl or the tub wall. This drain is in a not readily accessible space and in case of a sewer blockage you don't ever want it to overflow before other places do. – Jim Stewart Jun 02 '17 at 22:08
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    Are you sure you need a *bigger* tank? I'd be grading tanks based on first hour recovery, not size... – ThreePhaseEel Jun 03 '17 at 00:22
  • I'm going to follow the advice @JimStewart and just replace with another tank. I'll build a platform out of wood to match the height of the drain so that I don't have to cut it. Then, I'll just get the largest tank that will fit in the space. I'll cut the copper water lines and replace with flexible hosing to allow for additional space. The only question I have now is do I also need to install an expansion tank? Thanks for all of your help. – littleK Jun 03 '17 at 14:44
  • Noted, @ThreePhaseEel, I'll be sure to check compare tank recovery times. – littleK Jun 03 '17 at 14:52

2 Answers2

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My advice is to leave the old water heater where it is and install a tankless hot water heater. I installed one at a shop for a friend in Georgia a few years ago. They had a shower in the shop and I showered there several times and never had any trouble with hot water. 4 gallons per minute was more than sufficient for a decent water flow shower and never ran out of hot water.

I think the link below is to the same unit I installed. It was quite small so it will take up very little space.

https://www.amazon.com/Rheem-RTE-13-Electric-Tankless/dp/B003UHUSGQ/ref=sr_1_5?s=kitchen-bath&ie=UTF8&qid=1496426163&sr=1-5&refinements=p_n_style_browse-bin%3A542712011

Drew k

Gwydionforge
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  • The description for this 13 kW 240 V tankless water heater is that it would work for one shower so it would probably not by itself work for a whole apartment. It requires a 60-A 2-pole 240 V breaker and 6 AWG wire. This would probably require rewiring of the existing circuit since the breaker for the current tank is a 2-pole 30-A breaker. The service might or might not have capacity for an additional 30 A. The real crunch would be in winter time with (depending on the climate) extremely cold inlet water. A tankless gets only one pass at the water, but a tank can still give hot water. – Jim Stewart Jun 02 '17 at 20:34
  • The current circuit is probably wired with 10 AWG wire, but that would have to be determined. How many hot water use points would be used simultaneously? How many bathrooms? The only place one really needs very hot water out the tap is the kitchen sink supply. So one could use this 13 kW electric tankless as the central heater and put a 2 kW point of use 120 V heater under the kitchen sink. If you have a dedicated 20-A circuit for a disposer, you would plug this into the receptacle for the disposer, if you can do without a disposer. (I pitched our disposer 25 years ago, but we've a house.) – Jim Stewart Jun 02 '17 at 21:24
  • See, once you realize all you'd have to do to put in an electric tankless water heater, you realize why the ~50 gal electric tank is such a good idea. – Jim Stewart Jun 02 '17 at 22:02
  • I don't recall the flow rate of the shower at the shop, but it wasn't a low flow. I selected the 4gpm for the shop but think they make higher power ones. The big thing for me was it seems silly to store a tank full of hot water when you can just make it as needed. I used electric showers for years while stationed in England in a house without any hot water tanks. – Gwydionforge Jun 03 '17 at 02:32
  • All shower heads sold in the US now are max 2.5 gpm. This however is achieved with an engineered flow restrictor which can be removed and many people do remove them. I too have used electric point of use shower water heaters in Britain (in my case in the 1970s) and according to my recollection by US standards they were low flow. – Jim Stewart Jun 03 '17 at 10:42
  • Many are low pathetically low flowing. You really need a power shower there because the water pressure comes from the cistern in the attic. I had one in '04. A tankless water heater is a good reason to keep the restrictor in the shower and conserve water. I will install one when i buy a house...eventualy. – Gwydionforge Jun 03 '17 at 15:05
  • I remember an episode of "This Old House" in which Rich Trethewey (the plumber) was in London UK. The local expert explained that water pressures in London were very low because much of the municipal water distribution network was very old and simply could not stand the pressures used in the US. I had not realized that pumps were used to boost pressure and flow at the point of use. Because of lower pressures do UK houses use larger diameter pipes in the houses? – Jim Stewart Jun 03 '17 at 15:37
  • I put a natural gas fired tankless water heater in our house in 2005. It is a basic Bosch rated at ~120 kBTU/h, a discontinued model, very simple with a standing pilot light so no electrical connection. It replace a 40-gal ng fired tank with a burner of about 40 kBTU/h. A couple of years ago I changed shower heads from standard 2.5 gpm to low flow 1.4 gpm and we started having problems with the water heater shutting off in mid shower. I had to remove the flow restrictors in the new shower heads to keep the flow rate through the heater above the cut-off. – Jim Stewart Jun 03 '17 at 15:50
  • I have not been in England since '05, and that was at RAF Mildenhall near Cambridge. My brother in Virginia used to use a gas tankless I the meat plant for water over 150 (or 175?). Had good flow and kept it hot. – Gwydionforge Jun 03 '17 at 16:02
  • Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/59815/discussion-between-jim-stewart-and-gwydionforge). – Jim Stewart Jun 03 '17 at 16:05
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Performance of the Rheem RTEX-13 240V tankless heater from a seller Q&A is below. Do you see the problem? It only supplies 4 gal/min for a 20 deg F temperature rise. What is the temperature of the inlet cold water in the winter? You would probably want 105 F water for a shower. If your inlet water is 70 F then you'd want a 35 F temperature rise which means you would get a flow rate of 2.6 gal/min. This is great for one shower. If you installed a low flow shower head with a max of 1.3 gal/min, you could take a shower and simultaneously operate one other moderate use (which only needs 105 F water).

Georgetown SupplyMinimum activation flow rate is 0.4 gpm and the maximum flow rate is 4 gpm (RTEX-13 13kW/240V).

** Temp Rise Listing (F) and Flow Rates **

20 deg F temp rise = 4.00 gpm

30 deg F temp rise = 2.96 gpm

40 deg F temp rise = 2.22 gpm

50 deg F temp rise = 1.78 gpm

60 deg F temp rise = 1.48 gpm

70 deg F temp rise = 1.27 gpm

80 deg F temp rise = 1.11 gpm

90 deg F temp rise = 0.99 gpm

100 deg F temp rise = 0.89 gpm

Jim Stewart
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