Water Heater Help

**dachd** · 01-06-2011, 06:23 AM

Hello All!
We are a family of 6 with a 50 gallon gas water heater, kids showers & baths used to be primarily @ night, but the kids are getting older and they're now more in the mornings. 6 people trying to shower one after the other every morning...you're getting the picture!

What would be our best/most economical solution to this? A larger water heater, an additional water heater, on demand water heater, some combination???

Of course we're looking for the most economical solution both initially, and operating cost-wise. Also, our current water heater is housed in a somewhat smallish closet in our unheated attached garage (we live in NW AR) if that makes any difference.

Please include brand/model in recommendations if possible. Your help is very appreciated, Thanks in advance!

**jimbo** · 01-06-2011, 06:44 AM

Using the basci 70% rule, you get 35 gallons of water before the temp available drops to a level not warm enough for a shower. The most obvious answer is shorter showers and change to a 1.6 GPM shower head.

The next thing is to make the water heater HOTTER......BUT with a big caveat! It is just plain dangerous to send water hotter than about 130 out of the heater. What you must do is have a plumber install a tempering valve at the outlet of the heater. This will cost a lot less than a new tank or a tankless, and will stretch the available water.

Sounds like you might not have room for a second tank in parallel. So the final option is a tankless. Also the most expensive, by a lot $$$$$. Make sure you get a tankless sized for your demand. How many showers might be in use at the same time , along with a dishwasher, etc???

**dachd** · 01-06-2011, 07:15 AM

Thanks for the reply, Jimbo.

The closet that houses the h20 heater is 31"wx34"dx7'-4"h.

We have 2 showers that would run at the same time. Dishwasher is rarely run in the mornings, 99.9% @ night, so that shouldn't be factored in. The idea of a tankless is appealing, but I've seen so many bad reviews on so many of them...any recommendations on a particular brand/model for our situation?

**dachd** · 01-06-2011, 07:19 AM

If we were to go the tempering valve route, could we then just turn the temp on the heater up the whole way, or is that bad for the heater?

**jimbo** · 01-06-2011, 08:06 AM

Turning up the heater does shorten the life over all. Temperature kills things!

The big names in tankless are Rinnai and Noritz. But Rheem tankess are made by their parent company Paloma, and that is a big name internationally.

The biggest mistake is undersizing. Two showers would need a solid 5 gallon per minute. The LARGE print in the ad may show you 6 GPM. The fine print will show that spec for a rise of 40ºF. Meaning if the ground water is 50, you get 90º. If you actually want a hot shower at 110º, the spec may be 2.5GPM. So do some homework.

The unit is quite a bit more expensive than a tank. And the install will be very expensive, because in all probability you will need a new, larger gas pipe run over from the meter, and for sure your flue pipes will have to be replaced with stainless steel.

There is a ton of info and feedback all over the internet. It seems folks either love it or hate it!

**dachd** · 01-06-2011, 10:13 AM

wow, sounds like a tankless would be way too expensive....what about a larger water heater, say 75+ gal? I guess that would make a sizeable difference, especially if we coupled that w/a tempering valve?

Any recommendations on gas water heaters to stay away from?

**ballvalve** · 01-06-2011, 11:09 AM

You could feed that gas unit with a cheap 30 gallon electric rig to give it preheated water. Little space and no vent and gas line. And no problems as with tankless junk.

**dachd** · 01-06-2011, 11:20 AM

Thanks for the input, but we don't have enough space for an additional tank, the closet it's in is only big enough for one tank.

**Basement_Lurker** · 01-06-2011, 12:45 PM

40GAL for a family of 6 with teenagers is not an easy thing to live with. If you have no other location for a larger tank, then your best bet is to bite the bullet and isntall a tankless gas unit in that closet. Even if you do decide to go with a larger gas unit, you will still have to pay to have your water, gas, and venting lines moved. In the end, going with the tankless unit might be the best overall choice.

**jadnashua** · 01-06-2011, 12:47 PM

Raising the temp likely will shorten the life of the tank, but no certainty by how much. Where I live, they require a tempering valve. I run mine at 140-degrees and temper it to 120...you could play with the levels on both some, but don't want to go higher on the tempering valve. One thing you may want is to run an untempered line to the DW, as it works much better with hotter water (unless it has its own pre-heat circuit). they also make WH with a larger burner, so they can provide more hot water for a longer time, so those are your choices. The house is likely on a slab, so a drain water heat recovery system probably wouldn't be able to be installed, but that would help if you could. If it is multistory, you might look into that.

**dachd** · 01-06-2011, 12:53 PM

We're now thinking about this 75gal unit: http://www.sears.com/shc/s/p_10153_1...76000P?prdNo=3 has a 12yr tank & parts warranty.

Along with this tempering valve: http://www.watts.com/pages/_products...s.asp?pid=6888

Any opinions would be appreciated!

**Basement_Lurker** · 01-06-2011, 01:00 PM

hmm, for some reason I misread your closet size as 48`` high. That 75GAL unit with low flow heads on your showers will make a big difference.

**jadnashua** · 01-06-2011, 01:00 PM

Look into Rheem or Bradford White WH...a longer warranty often just buys the same tank and maybe a second anode rod. You'd likely have a more reliable unit from the ones mentioned. All new gas WH are required to have a special vapor ignition proof burner so if you stored combustable stuff nearby the WH can't ignite the vapors. Some burner designs are much better than others. The GE tanks at HD are made by Rheem, but BW is considered the best design by many.

**PlumbPowerHouse** · 01-06-2011, 01:09 PM

I would suggest possibly a tankless unit. As a new construction plumber, we install a lot of Rinnai and Rheem units. This solution is a little pricey, but you will never run out of hot water and the high efficiency of the product will allow it to pay for it's self in no time.

**jadnashua** · 01-06-2011, 02:40 PM

You didn't mention where you are, but that can make a difference in your choices, too. Where I live, I've measured mid-winter water temps of 33-degrees. You'd need a REALLY big tankless system to raise the water to a comfortable level with any flow. It works much better in more temperate places. It will also make a difference on your tank heater as well. The dip tube directs the cold water to the bottom, but it still ends up cooling the whole tank and the colder it is, the less you can use. The average house would need a closed combustion version since the thing needs LOTS of makeup air. For example, my basement was too small to install one in the water volume I needed (or wanted?!).