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

  • 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 2, 2017 at 14:53
  • 1
    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 2, 2017 at 14:56
  • Do you have any gas appliances?
    – mmathis
    Jun 2, 2017 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 2, 2017 at 15:14
  • 1
    Are you sure you need a bigger tank? I'd be grading tanks based on first hour recovery, not size... Jun 3, 2017 at 0:22

2 Answers 2


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.


Drew k

  • 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. Jun 2, 2017 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.) Jun 2, 2017 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. Jun 2, 2017 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. Jun 3, 2017 at 2:32
  • 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. Jun 3, 2017 at 10:42

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

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