Larger Water Heater + Small Water Heater

**BigJim** · 03-03-2013, 08:44 AM

It takes a good while for the hot water to get across our house to our bathroom and is a waste of water waiting for the water to get warm. Here is my question, we have a 10 gallon water heater that we only used one time and is in good shape. Would it work if I were to install the small water heater close to the bathroom and hook the hot water side of the larger water heater to the cold water side of the smaller one. That way we could have hot water quicker. Will this work?

Canucker · 03-03-2013, 08:52 AM

If you've got it, might as well use it. Pipe it in series. It'll work the way you want
You'll have the added cost of running it though, mostly standby losses but still a cost.

**BigJim** · 03-03-2013, 09:44 AM

Quote:

Originally Posted by Canucker

If you've got it, might as well use it. Pipe it in series. It'll work the way you want
You'll have the added cost of running it though, mostly standby losses but still a cost.

Hadn't thought about that, will the water get cold after the small tank is emptied as cold water from the other tank fills the small one or will the couple of gallons of cold from the larger one not make much difference?

**oh'mike** · 03-03-2013, 10:37 AM

Jim---E-plumber showed a return loop device that used the existing cold water pipe---that was a year ago---let's see if he remembers it----

vsheetz · 03-03-2013, 11:40 AM

Another way to go is to install a small tank-less on-demand heater local to the far end of the house. Be sure to get one that is temperature activated, not flow activated, so it will cut out once hot water from the main heater arrives.

old_squid · 03-03-2013, 12:28 PM

Only drawback I see would depend on how long the line is and how big, meaning how much cold water it can hold. That cold water is going to replace the hot water out of the small tank instead of coming out of the faucet. You might get hot water that slowly cools off and eventually warms back up as the little tanks volume gets replaced with the hot water from the main tank.

Research hot water reciculators. Some mount right below the sink and connect to the cold and hot water lines. Some have a push button you mount and when you are going to need hot water the pump runs and moves the cold water from the hot water line back through the cold water line until it sense the hot is there. You'll need to check with your local plumbing code though to see if that is allowed, so don't.

**TheEplumber** · 03-03-2013, 01:56 PM

Quote:

Originally Posted by oh'mike

Jim---E-plumber showed a return loop device that used the existing cold water pipe---that was a year ago---let's see if he remembers it----

Here is one version- with reviews-
http://reviews.homedepot.com/1999/10...ws/reviews.htm
I don't know if your idea will work. A couple thoughts come to mind:
Are you prepared to open a wall to grab the hot line and tie it to the heater the return it back into the wall? How will you handle the T&P valve? Are you willing to sacrifice the space compared to a small under counter pump? Like old_squid said, you might end up with a slight momentary cool down. Then you're firing the small heater- consuming electricity while the bathroom is not in use. I understand the heater is free- sounds like a good idea- but I don't know if its worth the effort to test

**BigJim** · 03-03-2013, 01:57 PM

Mike, hopefully he will drop by and tell us about it, that would be cool.

Vince, I already have the small tank and hope I can make that one work, I appreciate the suggestion.

OS, the line is at least 35 feet from the tank and is half inch line, the line could take several turns but if it were straight it would be about 35 feet from shower to tank. That is what I was thinking, the water would cool off some before the small tank was emptied and the hot from the big tank kicked in.

**BigJim** · 03-03-2013, 02:11 PM

Quote:

Originally Posted by TheEplumber

Here is one version- with reviews-
http://reviews.homedepot.com/1999/10...ws/reviews.htm
I don't know if your idea will work. A couple thoughts come to mind:
Are you prepared to open a wall to grab the hot line and tie it to the heater the return it back into the wall? How will you handle the T&P valve? Are you willing to sacrifice the space compared to a small under counter pump? Like old_squid said, you might end up with a slight momentary cool down. Then you're firing the small heater- consuming electricity while the bathroom is not in use. I understand the heater is free- sounds like a good idea- but I don't know if its worth the effort to test

Thanks EP, we must have posted about the same time. That would probably be the best and cheapest in the long run, even with the tank I have, being paid for, the pay back would be short. I haven't heard or seen one of the valves before now, that is really nice, thanks for the information, I appreciate it.