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Electric Tankless Water Heater

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Mar 04, 2014, 02:50 PM
plant a ceed
Electric Tankless Water Heater
My wife and I are empty-nesters, and recently bought a 2 bd, 2 bath condo. It's 902 sq ft, top floor in a two-story multi-unit complex.

We want to install an electric tankless water heater for two reasons: 1) we need the additional space in the "service closet" where our HVAC, water heater and stack washer dryer sit; and 2) the unit has had minor water drainage issues prior to our purchase that have been addressed and corrected, and we want to prevent reoccurrence of similar issues (hate to upset our downstairs neighbors).

Conversation with our plumber and internet research seems to show electric tankless WH's might not be the way to go. Can anyone relay their experience with them, or give any advice or other options for tankless/point-of-use versus traditional tank?

Thank you

plant a ceed
Mar 04, 2014, 06:01 PM
Here is a 6 year old review by Consumer Reports on tankless water heaters. I'm not a fan of them in most situations. Plumbing runs need to be short for maximum savings, water needs to be soft or they'll scale up very fast requiring annual maintenance. You will gain space with one, but I doubt you'll save money taking the higher purchase and installation cost and marginal energy savings. If you don't have gas available I'd probably stick to a tank and install a pan below it with a drain that is piped into the waste system. That will handle slow leaks but not a high pressure leak.

General Disclaimer

Any advice given here is general in nature and is not necessarily valid for your given area. If in doubt check with your local codes enforcement department for what is required when doing electrical, plumbing or structural work on your house. Permits may or may not be required in your area and home owners may not be able to DIY some tasks. I have no way of knowing if you have the skills needed to complete the tasks you are asking about, when in doubt seek professional assistance.

My advice may be worth exactly what you pay me for it. :-) For the record I did not stay in a Holiday Inn Express last night.
Mar 05, 2014, 12:15 PM
I looked into them. require (4) 40-amp circuits. don't have the room, and I don't like burning all those innocent electrons. I don't trust the ratings, cost is four times that of installing another standard electric heater, and there is some evidence that they can't provide enough water for leisurely soaking bathers in a row.

not my style.

sig: if this is a new economy, how come they still want my old-fashioned money?
Mar 06, 2014, 11:25 PM
The only time an electric tankless makes any sense is for a small, point-of-use heater - like in a remote bathroom or a vacation cabin. As a whole-house unit, they are a complete waste of time and money. Because:

1. Install cost. As pointed out above, they take 3 or 4 - 40 amp circuits. Most houses have 200 amp service with only a small amount of room for future expansion. So you are looking at adding a second service supply to the home.

2. Cost to run. Even by the manufacturers own specs, an electric tankless costs about the same or more to run compared to a standard tank electric water heater. The electric tankless cost more than a gas tank heater.

3. Water temperature. Tankless water heaters can raise the groundwater temperature by 40 to 45 degrees. Most groundwater is in the 62 to 64 degree range. Do the math and you get lukewarm water at it's hottest.

4. Water pressure. Even when new and clean a whole-house tankless unit can handle 2 to 3 faucets running at the same time. Once the internal lines start to scale over that will get worse.

5. Leaks. Just because there is no tank doesn't mean it can't leak.

Overall, you will be better off replacing your conventional tank with another one. The only down-side here is the space that it takes up.