Water Heater does not heat all 6 gallons

[bluefinger1]

I have a 6 gallon Suburban water heater, on the last trip we ran out of hot water much quicker than usual.

When we got home I ran the water heater, made sure it was nice and hot, then measured 3.5 gallons of water before it got cold.

If it wasn't heating at all, or just warm I could understand it, or if we were just blowing through all 6 gallons I could understand that.

But how could it heat only half of the 6 gallon capacity? Maybe an air bubble?

Thanks for your help.

[bluefinger1]

Francesca Knowles wrote:

bob_nestor wrote:
Not trying to be a smart a$$ here, but the hot water is discharged by pumping in cold water. That cold water mixes with the hot water remaining in the tank reducing the temperature. At about 3 or 4 gallons the hot water will be fairly cool. The amount of hot water one gets out is dependent on the temperature of the cold water coming in too.

First thing that crossed my mind, too.

But surely the O.P. thought of that and turned the incoming water off and then finished the "test" via draining by gravity into a measuring vessel...

Right, O.P.?

Wrong, I did it the dumb a$$ way. I did expect it to cool off, just not as quickly as it did. I will try it again by turning off the water and gravity feeding it.

Thanks all for your suggestions.

[Artum_Snowbird]

And certainly, if you are filling a tub or bucket with hot water at full speed, the mixing effect will take place much faster than sipping at the hot water with the burner on during a navy shower.

[Francesca_Knowl]

bob_nestor wrote:
Not trying to be a smart a$$ here, but the hot water is discharged by pumping in cold water. That cold water mixes with the hot water remaining in the tank reducing the temperature. At about 3 or 4 gallons the hot water will be fairly cool. The amount of hot water one gets out is dependent on the temperature of the cold water coming in too.

First thing that crossed my mind, too.

But surely the O.P. thought of that and turned the incoming water off and then finished the "test" via draining by gravity into a measuring vessel...

Right, O.P.?

[bob_nestor]

Not trying to be a smart a$$ here, but the hot water is discharged by pumping in cold water. That cold water mixes with the hot water remaining in the tank reducing the temperature. At about 3 or 4 gallons the hot water will be fairly cool. The amount of hot water one gets out is dependent on the temperature of the cold water coming in too.

[LittleBill]

is the units a true 6 gallon unit? or a 6 gallon usable.

based on the fact people don't shower at full hot, thus mixing cold, which makes it 6 gallon usable?

[bluefinger1]

Huntindog wrote:
Probably full of calcium and junk reducing it's capacity.
You can try removing the plug or anode rod and flushing it out.

It is only a year old, but I'll check it.
Thanks

[Huntindog]

Probably full of calcium and junk reducing it's capacity.
You can try removing the plug or anode rod and flushing it out.