Tankless Water Heater

Originally Posted By: Barry Thirtle
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A question on the first picture. Does the gas valve belong on the equipment side of the flex line or on the supply side?


Barry


Originally Posted By: jpope
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Good call. I would think that it should be on the supply side. I didn’t even catch that.



Jeff Pope


JPI Home Inspection Service


“At JPI, we’ll help you look better”


(661) 212-0738

Originally Posted By: kmcmahon
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anyone know what the price difference is between these and a tank type heater? Also do you know how long it would take to make up the diffence in energy savings?



Wisconsin Home Inspection, ABC Home Inspection LLC


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Originally Posted By: lfranklin
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A while back they ran almost $1000 around here. As they get more common thought the price might come down a little nachi_sarcasm.gif nachi_sarcasm.gif


Originally Posted By: jpope
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I think that their longevity is the real kicker. The average water heater uses 212 therms per year, these units use about 180. If you know your price per therm, do the math.


I was told that the Rinnai was $1200, installed. A standard tank in CA with seismic straps is about $400, installed.


--
Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738

Originally Posted By: ssmith3
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I have the Bosch Aquastar 125 I put it in 4 years ago and have had no problems with it. Had to fight with PG&E for 1+ yrs for a rebate of $200.00. They claimed it was NOT a water heater according to their definition. I called the local TV station and they jumped all over it. Got my 200 clams.


Here's a link to pics I just took of it for all to see. Not to many moving parts to break.



http://www.msnusers.com/boschaquastarwaterheater/shoebox.msnw



Scott Smith


Marinspection


Vice President NorCal NACHI Chapter


I graduated from collage. Now my life is all mixed up.

Originally Posted By: Bob Smith
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I have been asked to research the effects of tankless water heaters in relation to proper sizing of utility transformers


in the residential sector. Do you have any information/studies regarding how the electric utility companies are having to


make adjustments to handle any additional loading? Any information at will be most helpful.


Sincere Thanks, ![icon_smile.gif](upload://b6iczyK1ETUUqRUc4PAkX83GF2O.gif)

Bob Smith
Load Research Analyst
OGE Energy Corp


Originally Posted By: ssmith3
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Bob, The one I have is gas. I think most of the larger “whole house” units are gas. I may be wrong there, but icon_rolleyes.gif



Scott Smith


Marinspection


Vice President NorCal NACHI Chapter


I graduated from collage. Now my life is all mixed up.

Originally Posted By: Bob Smith
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Hi Scott,


Thanks for the fast reply! With the additional demands an electrical unit could add we are very interested in what it may take to meet the demand. With a few units out there it might not pose any problems, but if we have some builders that promote them to everyone in their new additions, we could have several on a circuit and over load the transformer if not sized for that load.
Hey I appreciate the reply, and maybe someone out here has run into the problem..

Take care and happy holidays!
Bob.


Originally Posted By: jpope
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forum and pose your question to Joe T., Bob B., and/or Greg F. (I know there are more of you, but those are the first to mind).


These guys are experts in electrical systems, commercial and residential, and Joe is (I believe) a consultant for the NEC.

They can probably answer your questions more so than the average HI.


--
Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738

Originally Posted By: Bob Smith
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Thank you Jeff, I will give that a try!


Regards, Bob.


Originally Posted By: dhartke
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In terms of energy cost, how do they compare with a Rheem Marathon tank heater?


Originally Posted By: M. Hancock
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Jeff Pope, rwashington and others,


Please be aware that there are numerous very important items to inspect with these gas units. As you well know, they are relatively new in the states and most plumbers don't follow the manufacturers instructions or don't know how to install these.

Jeff, in your first photo, it appears to me that this unit is not located near the gas meter and it appears that the gas pipe feeding this unit is ?", and it feeds another gas appliance, BBQ?. Based on the maximum input rating of 199,000 btu/hr, I'm guessing that the gas pipe for the whole house was never resized and is probably to small, possibly way to small. If you think about it, a 50 gallon tank style water heater has a max btu input of about 40 to 50K. A pretty sizable difference.

The second thing that should be looked at is the flex connector is probably not rated for 199K btu. It appears from the photo that the connector is a BrassCraft ?" I.D. 36" long. Looking at BrassCraft flow capacity chart, that connector is only rated for 125K btu and thus not rated for this installation. If it were ?" I.D. it would be rated for 255K btu and would be acceptable for this installation.

The next item to be aware of is the installation of the pressure relief valve. As you may have noticed, these units do not come with an opening built in as a typical water heater does, so it must be built into the hot water outlet piping. This is something that I have seen missed.

Next and a very important item is the venting system. In the photos posted by Richard Moore on 8/22 and Jeff Pope on 9/30, both are installed on the interior of a structure. These units are classified as a Category III vented appliance and therefore must use a vent approved for use. This typically means that the vent is stainless steel and all joints are sealed with silicone. There are only a handful of manufacturers of these vents and I'm sure they aren't cheap. They include Fas-n-Seal, Heat Fab, Saf-T-Vent, etc. PVC and B vents are not approved for this use. At least the photo posted by Richard Moore appears to be PVC.

Another thing to be aware of is the clearance to combustibles listed in the installation instructions. Even outdoors this is an issue. I have seen an outdoor installation where the requirement was 36" from the lowest projection of an eave, above the unit, to the vent termination, on an installation similar to the first photo.

Those are the biggest items that come to mind. I hope I didn't run on too long.

Just here to help! ![icon_smile.gif](upload://b6iczyK1ETUUqRUc4PAkX83GF2O.gif)


Originally Posted By: dspencer
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I install these myself. You must be Certified by Rinnai to purchase these for one. If you ever see any venting other than the PVC with Aluminum pipe insert for vent this is WRONG.( you might cause the vent pipe is about 100.00 for 3’ but is designed for air intake as well.)


As for the other brands...Rinnai is the best on the market (has a 4 gas chamber system, most others 1-2).

These systems also can have temperature change stations mounted at more than one location. If this is the case test the one location with water running and (keep water on!) then check the other station, you should not be able to change the tempature until the water is off from other location.


Originally Posted By: M. Hancock
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Darren,


Please note that Rinnai allows for Heat Fab Saf T Vent SC to be used as well. "The only vent/air intake systems approved for use with this appliance by CSA are the Rinnai/Ubbink vent system or the Heatfub Saf-T Vent SC vent system." This quote is directly from Rinnai's installation manual with misspellings left intact.

Saf-T Vent has an outer lining of stainless steel.

I can not find a listing in either UL or CSA for the vent quoted by Rinnai as acceptable to use, the "Rinnai/Ubbink" vent. I searched under Rinnai, Ubbink, and Rolux, the parent company of Ubbink. I would say this vent, with the PVC outer lining, should not be used without proof of a proper listing.

Just my thoughts.
[/quote]


Originally Posted By: dspencer
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My supplier only sells Rinnai vent kits only. Here are all specs for the system.


http://www.OhioInspectionsGroup.com/Rinnai.pdf from my training info. This will give you all piping sizes for vents, gas and water…have more info if anyone needs it.


Originally Posted By: rspriggs
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to create enough flow for the Aquastar to sense it!


A little warning for fellow off-the-gridders . . .



Exploring Planet NACHI . . . One house at a time.


Russ Spriggs,
Idaho Chapter Pres.
Coeur d'Alene, ID Home Inspectors
Coeur d'Alene Home Inspectors

Originally Posted By: psisler
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Can anyone tell me if there is a height requirement for mounting these type water heaters to a wall. I have looked but cannot find it. Such as distance to the floor/ceiling? Thanks.


Patrick


Originally Posted By: jorbeck
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I installed a Bosch Aqua Star 125NG in my house about four months ago. Really like it. It is a space saver and also quite efficient. As for what to look for, I would go to the manufactures installation instructions, i.e. on mine it strongly states that the vent must be a 5" B-vent with a minmum rise of 6 ft. Also it was very plain about the required clearances around the entire unit.


Absoutly love this thing, it opened up more floor space in my garge, which is small, and better yet my gas consumption was cut in half after installation. (my old water heater was 18 years old with lots of sediment in the bottom.