AO Smith Vertex, Bradford White High Performance, Or Eternal Tankless

[handyman923]

I am looking to replace a 10 year old Bradford White conventional 50 gallon water heater. We are a family of 4 with two small kids so we take a lot of baths. Also, we have a dual showerhead shower in our master that uses 4 gpm when we have both heads on. Needless to say, we often run out of hot water.

I am considering the following systems:

1) AO Smith Vertex (GDHE-50-NG) - This 100,000 btu heater has a 1st hour rating of 129 gallons and a recovery of 129 GPH. I like the fact that it is energy efficient, can deliver 3.2 gpm (at 60 deg rise) once the tank is empty, and recovers quickly due to the 100,000 btu's. However, I have read on these forums that a lot of pros don't like AO Smith and am also a little concerned that there are a lot of parts and electronics that could break down. The installation cost is probably a little more due to the venting, electrical, and condensate line.

2) Bradford White High Performance (GX-1-55S6BN) - This 80,000 btu heater has a 1st hour rating of 200 gallons and a recovery of 86 GPH. My basic understanding of this unit is that it superheats the water (160 or 180 deg?) and then uses a mixing valve to bring the temperature back down. I like that it has a great 1st hour rating, it is a pretty simple design without electronics to break down, and I can use my old venting. The recovery at 2.2 gpm (at 60 deg rise) is not as good as the vertex, but then again you are starting with a ton of water. I am a little concerned that the mixing valve could fail and that you could be scalded with 160 deg water. Also, I read that the minimum input for the mixing valve is 0.25 gpm. Is it possible to trickle a faucet to wash your hands and not reach this 0.25 gpm?

3) Eternal Tankless (GU195) - This 199,000 btu tankless can deliver 6.4 gpm at a 60 deg rise. I like that this tankless doesn't have the cold water sandwich problem, can give us endless hot water, and is efficient. However, I could see situations where we are starting a bath and taking a shower at the same time and exceed the 6.4 gpm. Then there is the cost of adding 40 ft of 1" gas line, and more parts to break down. I also read some very mixed reviews of this on Amazon.

At this point, I am probably leaning towards #1 or #2, but I am not sure. What do you think? Are there any other models I should consider?

Thanks so much for any advice!

[jadnashua]

If you have the vertical space where you can install one, with the showers, a waste heat recovery system would mitigate the need for a super large WH. There's a lot of discussions here, so use the search function. With a lot of tub baths, there's usually some time inbetween, so there, the recovery rate is less important, and the waste heat recovery system won't work. One way to make any WH appear larger is to run them hotter. Where I live, they require a tempering valve, regardless of what temp you run the WH. Mine's fairly old, and still seems to work. In a tub/shower, the modern valves all have a high limit adjustment you should use and check periodically. I prefer a thermostatically controlled valve in the shower/tub. There, it doesn't really mater what the incoming hot is, it adjusts itself to your preference.

[Dana]

What Jim said- a mid-sized drainwater heat recovery heat exchanger rated for >50% recovery at 2.5gpm, and the smaller/cheaper 76KBTU/hr Vertex and a 125-130F storage temp on the tank would allow you to take a 4gpm shower all night and day, no need for a bigger burner or a bigger tank. It's like adding another 50KBTU or more of burner to the system, but it's a "burner" that uses no fuel. (In OR there are even rebate subsidies for drainwater heat recovery heat exchangers, in steps by rated efficiency.)





EFI is the US distributor for PowerPipe, and they will open an account & honor the published price via phone with a credit card, and they don't tack on handling charges to the shipping- they're a very reasonable outfit to deal with.

[handyman923]

I like the idea of a drain waste recovery system, but I read that it needs to be installed on a vertical drain pipe, is this correct? We just have a crawl space, so everything under is horizontal. I do have 2" shower waste lines coming down from the 2nd floor, but they are in 2x4 walls, so I don't think the heat exchanger would fit...

Any other thoughts?

Thanks!

[Dana]

Yes, the heat exchanger has to be vertical to work. But even a 2-footer (Power Pipe R4-24 ) delivers 30% return, and would put out as much hot water in shower mode as the Vertex 100.

You might call Renewability (the makers of PowerPipe) and find out the exact outer dimensions of the 3" versions. The outer wrap is squared off and flat- if it's 90mm or less it'll just make it into a 2x4 cavity, but even if it's 100mm you can make it work with a bit of sculpting on the gypsum. Assuming you have at least 8' to work with, even with 2"x3" reducer couplings you should be able to fit a 3" x 72" in there, which runs ~59% return efficiency @ 2.5gpm.

They also make 2" drain versions which would surely fit, but you may have to buy them at a Canadian Home Depot (or order one through a US Home Depot) direct from Renewability at a more retail-type price.

A 2" x 72" is still returning over 50% @ 2.5gpm, and the 2" x 60" (available from EFI as well as Home Depot) still returns a respectable 46%.

In general, fatter & longer == better return efficiency, due to the greater surface area interface, and putting the tallest & fattest that fits (allow some room for the couplings) is usually worth it, even at full-retail. A 2" x 72" at full retail is still only about the price difference between a Vertex 100 and the 76K burner model, but the smaller heater + PowerPipe's "apparent capacity" and efficiency is bigger/better than the Vertex 100 without a drainwater heat exchanger.

[Dana]

BTW: The OR rebate may only apply if you're heating water with electricity, and they don't list any of the 2" drain models anyway.

[handyman923]

The other issue I see with the drain waste recovery exchanger is that the vertical 2" line is at the other end of the house. Would I need to run a 3/4" line from the house input to the heat exchanger and then back to the water heater? I like the concept, but I am not sure this will too easy to retrofit.

[Dana]

It DOES have to feed the cold water side of the HW heater AND the cold side of the shower to get the full efficiency out of it. (If it feeds just the hot water heater a 50% unit will only be delivering ~40%, which is still way better efficiency than just feeding the cold side of the shower with it.) With an open crawlspace I'd think the lateral runs of cold to/from the heat exchanger to the tank or to the cold input to the house would be pretty easy to implement, and the cold run to the shower would be pretty close to the drain pipe.

If the cold water input to the house is closer to the shower drain than the hot water heater, just putting the heat exchanger in series with the cold feed to the entire house accomplishes the same thing. (That's how my house is plumbed, with a 4 x 48 DWHX a bit north of 50% efficiency.) Under that configuration the other cold taps would be running other than cold-cold water when someone is taking a shower, but at Portland's relatively cool incoming water temps a ~50% heat exchanger would raise the incoming cold water to the mid to high 70s F in summer when the incoming water temp is highest, and about 70F in winter. When it's 75F indoors cold water stagnating in the distribution plumbing is also in the 70s, which doesn't bother most people. In warm-water areas like Florida it might take it up to an unappealing tepid temp for some people, but not in OR (or MA, where I live.) When another cold water draw is in progress, the output temp of the DWHX drops a bit too- it's something I've measured, but it's never been something anyone in my family has noticed or complained about.

Not having super-cold water out of the tap while someone is in the shower is a fairly small inconvenience to pay for the ability to take showers at half the energy use (or showers twice as long for the same energy use.) But if it's easier to plumb it to serve ONLY the hot water heater and the cold feed to the shower (or just the bathroom with the shower) it won't affect the temp of the cold water in the kitchen.

[ReviewinMalibu]

After our 2 yr old water heater failed, we had to replace it with a new model that required $1600 in parts and service. Grand Hall refused to pay any. We purchased a brand new home in 2010 that had an Eternal water heater by Grand Hall. Two years later the heater failed and had to be replaced with a new one. Eternal no longer manufactured the model we had, so they sent us the newer one that replaced it. The problem is that it cost over $1,600 in parts and labor to reconfigure and install this new model -- and Eternal (Grand Hall) refused to reimburse any of it. They said that the warranty only covered the unit, which they sent. But it was so different from the original it was very expensive to install. After only two years of use, we feel very strongly that Eternal (Grand Hall) should have backed up their product when it failed. It is ridiculous that we are out $1,600 for replacing a brand new water heater we only had for two years. If they changed the model so drastically, they need to pay for the installation when they replace a defective unit. I had multiple phone and email conversations with Eternal representatives, finally getting escalated to district manager Shawn Bacon. I emailed him the receipts for the expenses we incurred in replacing the unit. He told me since their warranty didn't cover the extra parts and labor Eternal was not going to reimburse us.

[jadnashua]

That policy is normal in the industry. It is also clearly stated in their documents. It's unfortunate, but not uncommon. I've paid a fair amount to replace my 'lifetime' WH twice now. The latest one had some configuration changes which made the installation more than a simple remove and replace. Different brand, similar policy.

[master plumber mark]

NOTICE: Dana appears to have a financial interest in Powerpipe. He posts the purchasing links, photo’s and other promotional materials. He has roughly 200+ Powerpipe shopping links posted across several forums. He also has just as many posts where he attacks anyone asking about any other manufacturer’s product. In this forum the other day, I asked a simple question about a competitor to Powerpipe and he started attacking me.

Thanks for the info