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dcj710 01-10-2013 05:44 AM

Installing a second electric water heater
 
Need to install a second electric water heater for a basement shower.

Our needs have changed, and current (relatively new) 55 gal isn't providing enough hot water for early morning showers since the temps have dropped.

I've read that they should be in series. Any suggestions, minimum size, schematics, etc. appreciated. Thanks.

md2lgyk 01-10-2013 08:16 AM

I would not put the heaters in series. Any time you used that shower, you'd be drawing water from both of them. Wouldn't accomplish much except to increase your electric bill. As for size, I think a 30 gallon unit would be more than enough, or a 20 gallon if there is such a size.

jagans 01-10-2013 08:19 AM

Why not in parallel, so you draw from both, doubling the Qty of hot water? Id hate to see your electricity bill! :(

paintdrying 01-10-2013 09:55 AM

55 gallon not enough? My advice is 20 years old but I think it will still apply. The best way is to disconnect the old heater and get the same type, then when you reconnect both of them every piece of pipe connecting them must be the same length. Each heater needs to work together. One working more than the other makes no sense. Water heaters may have changed in 20 years their maybe a better way now.

md2lgyk 01-10-2013 10:18 AM

Series or parallel, any time you use the shower you'll be drawing water from both heaters. I would plumb the shower's water heater totally separately.

Bondo 01-10-2013 10:36 AM

Quote:

Our needs have changed, and current (relatively new) 55 gal isn't providing enough hot water for early morning showers since the temps have dropped.
Ayuh,.... Just how big is the Army that showers at yer house,..??

55 gallons of hot water, is Alotta hot water.....

DexterII 01-10-2013 10:45 AM

Quote:

Originally Posted by dcj710 (Post 1090195)
55 gal isn't providing enough hot water for early morning showers since the temps have dropped.

Particularly since you alluded to the problem appearing, or at least worsening as the outdoor temperature drops, I would look at insulating pipes and/ot areas that the pipes pass through, before adding the expense of a second water heater. You may have some areas to address that could result in eliminating the need for a second heater, as well as reduce your home heating bills.

DidIDoThat 01-10-2013 11:45 AM

Quote:

Originally Posted by dcj710 (Post 1090195)
Need to install a second electric water heater for a basement shower.

Our needs have changed, and current (relatively new) 55 gal isn't providing enough hot water for early morning showers since the temps have dropped.

I've read that they should be in series. Any suggestions, minimum size, schematics, etc. appreciated. Thanks.

If you added a tempering valve to the existing tank, you can turn the temp up an increase your volume of usable hot water by as much as 50%

jagans 01-10-2013 11:53 AM

I bet you have teenagers, right? Send them into the military, then your 55 will work fine. :thumbup:

By the way, outdoor temp drop should have nothing to do with it, unless someone is heating up the bathroom with steam before going in there. The HWH is going to heat the water up to your set point, regardless of outdoor temp.

I guess I am assuming you dont have uninsulated copper lines that run through an unheated crawl space in Antarctica. :eek:

bcgfdc3 01-10-2013 04:36 PM

If 55 gallons of hot water is not enough you may want to look into a tankless on demand system. They are a little pricey but the usage cost would probably offset that and the cost of a whole seperate tank and install.

Just my opinion

TheEplumber 01-10-2013 07:37 PM

Quote:

Originally Posted by dcj710 (Post 1090195)
Need to install a second electric water heater for a basement shower.

Our needs have changed, and current (relatively new) 55 gal isn't providing enough hot water for early morning showers since the temps have dropped.

I've read that they should be in series. Any suggestions, minimum size, schematics, etc. appreciated. Thanks.

Have you bothered to make sure your existing heater is firing on all cylinders?

tylernt 01-11-2013 12:56 PM

Quote:

Originally Posted by TheEplumber (Post 1090653)
Have you bothered to make sure your existing heater is firing on all cylinders?

^^^ This.

As for water heaters in series or parallel, it costs the same to heat a given volume of water regardless of whether you use one heater, two in series, or two in parallel. Or three or four. Watts is watts and BTUs are BTUs -- it requires the same amount of energy to effect a 20F rise of temperature in 40 gallons of water no matter how you configure your heater(s). Whether in series or parallel, each of two heaters will only have to work half as hard as one heater for a given number of gallons.

So, if you only pay by kWh, your bill will not increase unless you also increase your consumption -- and even then, your bill will only increase the same percentage you increase your consumption.

What will increase is the peak electric consumption. If your utility monitors and charges for peaks, then yeah, two heaters will spike your bill in a most unpleasant manner.

jagans 01-11-2013 01:21 PM

OK I have to ask what seems to me to be a pretty obvious question.

Piped in parallel, water would be drawn from both heaters at the same time, and therefore both heaters would cycle on at about the same time, replenishing the hot water in both tanks sooner. If they are in series, you are dumping the hot water from heater 2 into heater 1. Since it is already hot, heater 1 will not cycle on untill all the hot water in tank 2 is used up. Is this sound thinking?

I think that the poster that recommended an on demand unit is correct with this particular family, as they seem to have an insatiable appetite for HW. I don't know if an electric on demand unit can keep up, but there is probably one that can.

I have heard that Rennai, and Takagi makes very good units.

tylernt 01-11-2013 01:26 PM

Quote:

Originally Posted by jagans (Post 1091055)
Piped in parallel, water would be drawn from both heaters at the same time, and therefore both heaters would cycle on at about the same time, replenishing the hot water in both tanks sooner. If they are in series, you are dumping the hot water from heater 2 into heater 1. Since it is already hot, heater 1 will not cycle on untill all the hot water in tank 2 is used up. Is this sound thinking?

That's my understanding, yes.

Quote:

I think that the poster that recommended an on demand unit is correct with this particular family, as they seem to have an insatiable appetite for HW. I don't know if an electric on demand unit can keep up, but there is probably one that can.
They do make them, but they often require an electrical service upgrade. Some of them can require 120A to 150A just for the water heater, let alone the rest of the house.

dcj710 01-14-2013 02:05 PM

After the initial post, I checked out the Price/Pfister (shower in basement) online and found a number of people reporting mix cartridge failure about 1 1/2 years after installation. That number is about right, so I replaced the cartridge and the problem is solved.

Interesting replies regarding different ways of adding more hot water. Thanks for the suggestions.




Quote:

Originally Posted by jagans (Post 1090262)
Why not in parallel, so you draw from both, doubling the Qty of hot water? Id hate to see your electricity bill! :(

PARALLEL

Quote:

Originally Posted by md2lgyk (Post 1090257)
I would not put the heaters in series. Any time you used that shower, you'd be drawing water from both of them. Wouldn't accomplish much except to increase your electric bill. As for size, I think a 30 gallon unit would be more than enough, or a 20 gallon if there is such a size.

NOT IN SERIES

Quote:

Originally Posted by md2lgyk (Post 1090346)
Series or parallel, any time you use the shower you'll be drawing water from both heaters. I would plumb the shower's water heater totally separately.

PLUMB SEPARATELY. (This is the direction I was inclined to go in. Was told this would also eliminate the change in shower temp water when someone runs water for another purpose)


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