2 water heaters, series or parallel??

[curbguy]

The whole story as short as I can make it. Currently 1 40 gallon electric water heater. I am replacing with a 50 gallon gas. When this is done I want to put a electric 40 gallon in master bath I got for $30 brand new. I will use existing circuit to power it. What I want to accomplish:

MB is about 90 feet away from water heater. With circulating pump installed takes about 1 to 2 minutes for hot water to hit bathroom. Without pump it can take up to 4 or 5 minutes. I have no issues of running out of hot water. I just want to set up 2 water heaters so I can remove pump and get hot water faster to MB. I also want to do this the most efficient way possible.

My thought is to supply MB (2nd) water heater with the hot side from the 1st water heater and this will save me money not having to have the electric heat as much water. The first will supply the rest of the house as they are all within 10ft and only as far away 25 feet of 1st water heater. I believe the circulating pump in my case is costing me lots of electricity. I am just looking to get hot water to my MB quickly and saving money on utilities. If I supply cold water to MB it would seem to me this is more expensive as I have a gas WH heating cold water and the electric doing the same.

Any thoughts on this? Anything else I need to know to do this correctly??

Thanks for your help.

 

[IFIXH20]

In order to install the 2nd water heater for the MB only , you need to tap into the main hot water trunk line that feeds the MB. Where are your water lines (under slab, attic, basement) ? Not sure how much you will save using two source of energy instead of one. If the MB has it's own water heater you still will not have instant hot water at the fixtures. Check out a Grundfos or other system with timers, if you are not running out of hot water , this may be the way to go.

 

[havasu]

I'm also wondering why a small Grundfos wouldn't be a better, cheaper and more energy efficient way to get hot water to the master bath. I had one for years and it was great.

 

[curbguy]

IFIXH2O said, "Check out a Grundfos or other system with timers, if you are not running out of hot water , this may be the way to go. "

HAVASU agreed. I went and looked up Grundfos and I am not sure what products you are referring too, Grudfos what?? What exactly do I need to look at.

I have a crawl space and all plumbing is accessible. I have checked the plumbing of the recirculating pump and it is hooked up correctly per instructions. It has electricity and I can hear it running. I have it on a timer to run early, midday, and early evening.

I thought of one other thing. My shop, (out building) has a small apartment in it that my son lives in. The shop water was tied into the cold water supply just under the MB as that was the closest place to tie in and that is what the plumbers recommended. Could the circ pump be trying to circulate the water to the shop as well. It is a 200 foot run to the shop. If this is the case then would a hot water heater be the answer with these circumstances?

I have the extra water heater, I bought it for $30 at a local retailer that was going out of business and never installed it. So the cost of the water heater is negligible. My electric bills are very high, much higher than neighbors. I realize I have to residences, but my son works lots and is not using electric all the time and it is a small apartment. I did have the shop electric turned off for 2 days and had the utility company keep track of difference and it is about $60 bucks a month for the shop. I am sure that can go up or down depending on time of year and other factors, but my bills are close to $300 a month in the winter and $200 in the summer. So I am looking to shrink my electric bill if possible. One of the reason I am going to a gas water heater and gas dryer as soon as the new utility/ laundry room is done.
I would still have the electric water heater for the MB, but being supplied with hot from the gas water heater. The circ pump not running possibly out to the shop, and that may decrease my electric usage???

Any of this making any sense???

Thanks for your time.

 

[Beni]

Hum...While the elect. water heater for the MB would work, The circ pump should be doing a better job of getting hot water out to the end of the run. I assume all your hot water and hot water return piping is insulated. Otherwise your heating the crawl space with the hot water piping when the circ pump runs....

I would turn the HW pump on and check to see which lines get hot. I would check the cold water piping too as its not too uncommon to see it going to the cold side.

A check valve should be installed on the cold water line serving the main water heater. if there is hot water upstream of the check valve, the check valve needs to be replaced...