DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   Two water heaters or one? (

krolling1 10-06-2012 08:57 PM

Two water heaters or one?
Preparing to move into the home we just purchased, discovered there are two water heaters (installed in series) I am pretty sure the second unit is to keep the water heated as the first heats additional water. Previous family was large. It's just my wife and I so curious as to the benifit or not of leaving heaters as they are or disconeccting the second and having the plumbing changed to use only one heater.


joecaption 10-06-2012 09:02 PM

No reason to have had two heaters hooked up like that in the first place.
It's just going to cost you twice as much on your power bill if left that way.
Post a picture of what you have.

rjniles 10-06-2012 09:32 PM

Turn the power off on the first tank. It will act as a tempering tank to feed the active tank.

krolling1 10-06-2012 09:39 PM

Two water heaters or one?
Not able to post a picture yet, haven't moved in! From what I can tell, listening to the heater(s) coming on when turning on, #1 is set higher than #2 (each is on seperate breakers which may be normal?). #1 makes that "sound" inside when first turned on #2 doesn't make any sound at all. If I just turn off the power (since the hot water outlet pipe goes directly to #2 coldwater inlet) I would have no hot water since the water in #2 (I think) should be the storage tank? Very confusing to try to explain this, hope I am not confusing you more than I am already confused!! I was thinking of having a plumber come out and disconnect #2 and re pipe #1 as the only heater used. Save #2 for when #1 bites the dust!!

oh'mike 10-07-2012 04:53 AM

Typically tank one is a 'preheating unit--tank two is set to the higher temperature---

Disconnect power to tank one---no need to per heat the water any more.

Removing it is the best option--that eliminates one more possible late night failure---(on a holiday weekend,on a Sunday)

beenthere 10-07-2012 05:21 AM

YA, just leave the first tank as a tempering tank.

AllanJ 10-07-2012 07:02 AM


Originally Posted by krolling1 (Post 1025508)
Save #2 for when #1 bites the dust!!

It must be emptied fully and the drain valve and top ports left open (nipples with gadgetry inside them removed) so any remaining drops of water will evaporate and moisture from the atmosphere doesn't condense inside.

Two water heaters in series will behave differently and require different temperature settings depending on the pattern and volume of hot water usage in the household.

krolling1 10-07-2012 01:38 PM

Thanks for your help. I had not thought of that, if that is the way we go I will be sure to drain the tank. Also, from the posts I m trying to figure out whixh tank is the one working (or pre heating). I got hot water in the line between the tanks (from #1 hot water outlet to #2 cold water inlet) but there was no hot water coming from #2 hot water outlet.

beenthere 10-07-2012 04:35 PM

No reason to drain the tank not being used to heat the water. Or to disconnect it.

Turn off the breaker to the tank that the cold water supply runs into. Thats all you need to do.

All times are GMT -5. The time now is 06:49 AM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1