Hot water heater question

I inspected a house with two hot water heaters. On one of the hot water heaters both of the water lines were hot. What would explain this?

Were they plumbed in series?

You don’t have to heat hot water. I think you’re talking about a cold water heater. :wink:

At this time of year they are all hot water heaters here Joe.:smiley:

Yes, you do have to heat hot water. If the tank temperature is set at, say, 120 degrees, when the temperature drops to about 110 degrees (still very hot) the burner will ignite and heat the hot water.

For many years I would get calls at my office from kids with that same premise, and I just loved popping their little balloon…:smiley: :smiley: :smiley:

I don’t know if they were in series. One was upstairs and the other was down stairs.

Being is series would be one explanation.

PS Jae, that would technically be “Hot Water RE heater”, kids.:wink:

Very often both lines will be hot due to the heat in the unit conducting to the cold line. The cold line should turn cold (provided it’s not in series) when a hot faucet is turned on and cold water enters the tank.

Hope this helps. :slight_smile:


Some of the answers you have received are correct, if you can decipher all of them.

I hope this will help.

I own a house that mimics exactly the setup you describe. We have two water heaters, plumbed in series. The first and main one, is powered by propane gas (that may run out at an inconvenient time…like during a snow storm) and the second is a simple electric unit, set at a slightly lower temperature, that is powered by the normal power line and during power outages, our diesel powered back-up generator.

Why all of the redundant back-ups? We live on top of a mountain, in a remote area.

Anyway, if you simply turn on all of the hot water faucets, throughout the house for a few minutes, and then check to see if the in/out lines are either hot or cold, you should be able to solve this mystery in short order.

Your CarolinaNeighbor,

BV Alvarez, Founder & CEO, Air Chek, Inc.
Fletcher, NC

By the way CarolinaInspector, I don’t mind answering questions like this, one on one. I’ve been involved in home construction and repair since 1959 and I’ve seen a lot of strange things during the past 47+ years. You may call me on my private toll-free number 1-877-684-2642 'most anytime, if you think I can help.

Connecting two hot water heaters in series is a great way to get rid of the efficiency loss factor when there is a long run between the water heater and the plumbing fixtures. You must drain off cold water in the lines from the water heater to the fixtures to get warm water. Water heater must then recuperate from the cold water makeup for the water loss to the fixture. Placing a second water heater closer to the source of use provides instant hot water and the cooler water in the pipes from the first hot water heater to the second water heater becomes absorbed in the second. This is an effective way for a plumbing system not properly designed, with long runs without a loop system incorporated.