Dual hot water heaters not always hot

[jricci1960]

I have two 40 gallon hot water heaters in my house. The cold input comes in and splits off into both tanks. The hot output comes out of both tanks and joins into one pipe which then distrubutes the hot water throughout the house.

I have noticed in recent months that one shower will be hot and the other shower will be warm. It doesn't seem to matter which shower starts first. Sometimes the one that starts first is warm and the second shower is hot and sometime the shower that starts second is warm and the first shower is hot. Sometimes both showers are fine. :scratchhead:

How do hot water heaters work when there are two of them? Do they both get drawn from equally or does it work some other way?

Thanks in Advance,

Joe "Warm Shower" Ricci :)

[Aaron91]

Hey Buddy how's it going?

Your gonna have to give us some more information like...

Are they gas or electric(nat or pro), or is it a mixture, one elec and one gas?

How old are the heaters? Check around for a tag with a serial number on it and post it up here.

Picture's always help.

So far we know there's 2- 40 Gallon Water Heaters.

[JCsPlumbing]

A little more info please.

When were the heaters installed?

How long have you lived there?

Any changes in people living there?

When does this seem to happen? Morning? Evening?

Municipal water or well water?

Based on the small amount of info I'll guess drain them both a couple of times with the water ON. Blow out any sediment.

Could be water heater "stacking" based on usage behavior.

Might be pressure balancing valves being used at the same time.

[haycad]

also what type of shower valves do you have? did i understand correctly its always the same shower thats warm. (master or main?)

[Aaron91]

It doesn't seem to matter which shower starts first. Sometimes the one that starts first is warm and the second shower is hot and sometime the shower that starts second is warm and the first shower is hot. Sometimes both showers are fine. :scratchhead:

Haycad- He said it depends, it goes back and forth and sometimes they're both fine.

[rombo]

from where the cold and hot split to each tank are all pipes the same length (symmetrical piping).

or the other common one on electric tanks is one tank has blown an element and is acting like a mixing valve

[haycad]

he doesnt clarify if its the same shower unit that does it.

[drtyhands]

Are there any other devices connected to the hot water system,pumps,valves etc.

[JCsPlumbing]

Do you have any River Birch trees in your area?

[MrsSeatDown]

Either all your questions scared him away or he asked and left not expecting a reply. . . peculiar:scratchhead:

[NHMaster3015]

One of the elements is burned out.

[drtyhands]

One of the elements is burned out.

I don't see it.How does one out of four elements feeding one house supply alternate the shower valve temperatures.

Thanks:)

[jricci1960]

They are both gas hot water heaters. Both where installed on Aug 2000. I have lived ther the entire time and there has been no changes as to the number of people that are living there. I have municipal water. We take showers in the morning so I've only noticed it then. Don't know if it happens at night.

[jricci1960]

also what type of shower valves do you have? did i understand correctly its always the same shower thats warm. (master or main?)

They are both Delta Monitor single lever shower values. No it's not the same shower all the time. It changes.

[PLUMBER RICK]

shut off one heater and test the temperature at the tub with a 5 gallon bucket and a thermometer.

a 40 gallon should deliver 70% (28 gal.) of hot water 100 degrees plus.

fill and dump the 5 gallon bucket in the tub.

then repeat the process with the other heater.

chances are you have a bad thermostat.

rick.

[jricci1960]

There are no other deviced connected to the hot water heater.

[jricci1960]

from where the cold and hot split to each tank are all pipes the same length (symmetrical piping).

or the other common one on electric tanks is one tank has blown an element and is acting like a mixing valve

Yes they are the same length. What do you mean when you say one tank is acting like a mixing valve?

[rombo]

i mean on may not be heating and is mixing the hot water from the functioning with cold water from the broken tank