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NinjaDave 09-22-2009 04:18 PM

Hot water issue
So I have 3/4" piping running throughout my house and a 40 gallon water tank. I couldn't get the water for my shower/bath to stay hot for longer than 2 mins, then it would go from hot to freezing in like 30 seconds.

So we went out and bought an 80 gallon tank, i figured that was the problem. No such luck, I just got it up to 5 mins of hot water and it would go from hot to lukewarm.

Well, the tub had a single knob to turn the water on. So we went out and bought a two handle set up, I figured the single knob was mixing too much cold into the water. No such luck.

Now the water heater is turned up to 125. When I had it higher, the water got hotter, just didn't last longer. And the heater is on the other end of the house from the bathroom. Is it the 3/4 piping? Only thing I can think of. It's not insulated, so I was thinking of boxing in the I-beam and insulating it after I ran my electric for the basement.

Any other ideas as to why this may be?

kok328 09-23-2009 07:36 AM

Is this a new problem?
Is this an electric or gas water heater?
Why would you replace the water heater given these symptoms?
3/4" piping for the runs will eventually reduce down to 1/2" at the destination points. I don't even know that they make fixtures that accept 3/4" piping.
Building a boxed in I-beam won't help much, you should probably consider insulating the pipes themselves w/pipe wrap.
Did you make sure to install a dip tube in the new heater?
Is there any sediment (i.e.-calcium) clogging the hot water flow and thus only allowing for cold water?

NinjaDave 09-23-2009 08:02 AM

I bought the house about a year ago, and it's been an issue for us since we bought the place, how long it's been like this I have no idea.
Electric heater.
I didn't think a 40 gallon tank was big enough?
Dip tube? I didn't install the heater, my mother-in-law's handyman did (she paid for the whole thing). What is it? And how can I check to see if it's been done?
There shouldn't be any sediment, they heater is only 3 months old. And it's been like this before it was installed.

kok328 09-23-2009 09:35 AM

Being that this an electric unit and it's relatively new, I have to assume that the elements and tstats are working and set correctly.
Dip tubes typically come preinstalled on hot water heaters but, those not familiar with them, tend to discard them as they think that it's just some type of protective device installed for tranporting the heater. You'll have to disconnect the cold water supply line and see if there is a long tube installed that directs the incoming cold water supply to the bottom of the tank where the heating occurs and also forces the hot water to the top of the tank where it exits the hot water output line. While your at it, you might also want to see if the handyman installed the dip tube on the wrong side of the heater (hot side versus cold side) I'm not sure if this even possible but, I've seen stranger things happen.
I didn't mean sediment in the tank but, sediment in the fixtures (i.e.-mixing valve and/or pressure balancing valve) I also assume that this is not the problem being that you replace the entire fixture thus a missing or incorrectly dip tube can be primary reason.

NinjaDave 09-23-2009 10:59 AM

ok, i'm gonna have to go get a pipe wrench, since i don't seem to have one and the biggest wrench I have is 15/16 and it's a hair too small.

NinjaDave 09-23-2009 12:46 PM

I may have solved it, and it wasn't the heater.

It seems when they came and installed the washer, they hooked a hose going from my utility sink to the cold outlet on the washer and the hot directly from the pipes. Well the sink only has one handle (has to be removed from the hot to the cold and vice versa). Well, the hot water comming from the sink was constantly on, as was the cold. I turned the hot water off from the sink. So I think it was draining the tank, or at least a good portion of it.

kok328 09-23-2009 01:51 PM

If you say so, I know both the hot and cold going to my washer are always on.

NinjaDave 09-23-2009 02:52 PM

that's the thing. I do. I have the hot comming straight from the pipes and the cold comming from the sink (I could have it comming from the pipes too, just been too lazy to switch the hoses). The Sink though had both the hot and cold turned all the way on.

I'll find out for sure when I go home tonight, figured i'd give it a few hours before I jumped in the shower to try it.

Redwood 09-23-2009 04:23 PM

A hot/cold cross connection would be a likely suspect.
along with dip tube problems, slab leaks and a few other things.

NinjaDave 09-23-2009 09:17 PM

yay it's fixed. Thanks for the help guys

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