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blckolds · Jan 22, 2009, 06:36 PM

My house has copper piping running through out it. It also has hot water boiler for the heat. After 10 minutes I'm running out of hot water. I went out and replaced the hot water heater since it was getting old. It's a 50 gallon gas tank. Than I replaced the water pressure reducer. And whatever I do I can not get the water to stay hot. In the beginning it gets hot however after few minutes I have to start turning the cold water off in order to keep the temperature close to the same degree.

I have couple questions, I'm not sure if they are valid or can be related to this problem. Water pressure regulator I put in has a maximum of 35 psi. Since the cold water is feeding both hot water boiler and the hot water tank is that pressure sufficient? Water department came out and checked the input to the house and it's at 90 psi. The reason I'm asking this is cause I was talking to someone at the water department who said since the hot water heater works with gravity if there is not enough pressure going into the tank you won't have enough pressure to push it out. Also I thought maybe there is a cross between hot and cold water pipes but I turned the valve to the hot water tank and turned the hot water on. Once the hot water ran out it didn't turn into cold so I don't think that is the case. I am seriously lost! Any help would be greatly appreciated it. Thank you in advance

Berk

massplumber2008 · Jan 22, 2009, 07:29 PM

Hi Berk...

With all the information presented I'm thinking that it may be possible that the DIP TUBE (see picture) of the new water heater has been damaged during installation or it may simply be defective from the start...

To make this even more difficult, that pressure regulator with a 35 PSI maximum concerns me here, too... BUT I DON"T THINK THIS IS THE ISSUE HERE.. ;)

Did you solder fittings directly onto the nipples at the heater.. If so, you may have melted the dip tube and that would present as about 5 minutes of hot water with a need to choke the cold water flow down as you have... hmmm.. Here, cold water would be introduced at the top of the heater (instead of at the bottom) and would mix with the hot water (at top of heater) and produce warm water after only a few minutes... depending on where issue at dip tube is...

If you didn't solder fittings onto the nipples then could also be that the dip tube is cracked or broken off somehow... hmmm..?

Check temp. at all faucets.. Is this isolated to tub/shower valves only? Did you solder fittings onto nipples at heater, etc..?

It could also be other things, of course! Let us know more here...

MARK

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afaroo · Jan 22, 2009, 08:05 PM

Hello Berk,
I agree with Mark, it could be the Dip tube.

Water pressure of 35 psi is low but has nothing to do with your problem in this case, you can increase the pressure to 45-60 psi if you want, click on the link below and you will see how the dip tube works, good luck.

John

How a water heater dip tube works and what it looks like.

blckolds · Jan 22, 2009, 08:57 PM

You guys are awesome, thank you so much for quick responses! They were not welded on so that's one thing out of the way :) As for the temperature at other faucets. It is generally same through out the whole house, one doesn't get hotter than the other. Dip tube does sound like it could be the issue. I will try to take it apart and see I can find any issues with it. Just as a side question, I don't know if this could help you guys. But in the beginning the hot water boiler use to function much more efficiently. If you turned it up to 75 it would get so hot, it would run people out of the house. It doesn't want to heat up above 73 degrees. I don't want to confuse anyone with more info but thought maybe this could be related to the issue I'm having. Again I really appreciate your help!

Berk

Milo Dolezal · Jan 22, 2009, 09:37 PM

Hey guys, let me jump in...

Berk, it is normal to run out of hot water in 10 minutes with 50gln hot water heater. If you are using 4gln per minute shower head you get maximum of 12 minutes of hot shower. However, once you start depleting hot water, cold water will start entering your heater diluting existing, and still unused, mass of hot water, making it warm. This is especially noticeable in winter months.

You have 3 solutions to this problem. First one is easy and inexpensive fix. Second one is costly but will produce highly satisfactory results. Third one is also costly, but lot cheaper then #2.

1. Install, and use, Low Flow Shower head. At 2.2 gln per minute, you will just about double your showering time.
2. Install Tankless hot water heater. It has endless supply of hot water.
3. Install another 50 gln hot water heater in synch with the first one. It will now act as Hot Water Storage Tank. First heater pre-heats water to 110F , water transfers to the Second heater which will heat water to the desired temperature, usually around 125F.

You can also install good insulation on your hot water pipe and thermal jacket on your hot water heater. It won't do too much but will raise the R-value of your heater by few Points.

Let us know what you plan on doing... Milo

afaroo · Jan 23, 2009, 10:29 AM

Originally Posted by blckolds

in the beginning the hot water boiler use to function much more efficently. If you turned it up to 75 it would get so hot, it would run people out of the house. It doesn't wanna heat up above 73 degrees. I don't wanna confuse anyone with more info but thought maybe this could be related to the issue I'm having. Again I really appreciate your help!!

Berk

I really didn't understand of this 75 degrees and 73 degrees, do you mean that you are setting your gas valve at this setting if this is the case the setting is low you should set the gas valve at least at 120 degrees, Thanks.

John

massplumber2008 · Jan 23, 2009, 12:24 PM

John...

Blkolds is talking about setting his THERMOSTAT at 75 and how it used to heat up super fast... now has trouble maintaining 73... ;)

Milo had some great additional ideas for you to check on blkolds. Was this reduction in hot water the reason you replaced the old heater or is this a new issue since you installed the new heater... let us know.. ok?

For now, I don't think the issue between the heat and the hot water are related... but let's see. Answer all questions...

Thanks.

afaroo · Jan 23, 2009, 12:33 PM

Thanks Mark I read it wrong.

Regards,
John