I am having a problem with a tankless water heater that is less than a year old. The manufacturer is blaming the plumber for installing galvanized dielectric unions in line with the copper pipe. They are voiding my 10 year warranty. I am in the city, with city water that comes mostly from wells and also have a water softener installed. Does it seem feasible that corrosion from these fittings could have caused a problem in less than a year?

Your installer should have used dedicated "Water Installation Kit." That kit is designed to properly connect thankless heater with house plumbing. It appears like your Installer tried to save few dollars and created this unpleasant situation instead. I would call him and ask him to come back to correct his installation.

Question: What is wrong with your heater ? What brand heater is it ?

Back to you. Milo

Im curious also. What brand is the heater? You really should have gotten ahold of the installing plumber instead of going directly to the manufacturer. The original plumber most likely could have gotten it warrantied for you, but now that you have spoken to the manufacturer, you may be out of luck. Plumbers sometimes have ways of getting products warrantied from their supplier without going through the manufacturer. Wishing you the best of luck here. Please do let us know the brand though, may ring a bell for problems with them with dielectrics or not.

The unit is an Eternal made by Grandhall. The unit started having problems with an error code after only 10 months. The plumber was trying to make the unit more servicable with the unions. They have been removed but the manufacturer is saying corrosion from the unions have damaged the unit which is now only a year onl. I have city water and a water softener. Hard to believe in this short of time that could be the case. I saw the unions he removed that had a small amount of corrosion but I can't believe the unit can't handle it.

Im curious also. What brand is the heater? You really should have gotten ahold of the installing plumber instead of going directly to the manufacturer. The original plumber most likely could have gotten it warrantied for you, but now that you have spoken to the manufacturer, you may be out of luck. Plumbers sometimes have ways of getting products warrantied from their supplier without going through the manufacturer. Wishing you the best of luck here. Please do let us know the brand though, may ring a bell for problems with them with dielectrics or not.

The unit is an Eternal made by Grandhall. The plumber got the same answer so I contacted the manufacturer directly. The plumber I used is a good one that sells a different brand of tankless but I researched the units and thought this was better and a better company. I was wrong. The plumber spent made 3 trips and spent over 5 hours troubleshooting the unit and hasn't charged me for any of that time.

Oooh, eternal. I have only had one experience with them (or I guess you could call it three to be more exact). I first installed one about three years ago. A few months later the heat exchanger was leaking. I had used dielectrics. Got a new one, and did not use dielectrics per manufacturers suggestion. Guess what, about a month later, another leaky heat exchanger, same location as the first. Sent pics of install from gas piping to venting to condensate drain, etc, to get another warranty. Get the third one, and no more than two months later, another leak, same general area of heat exchanger. Water quality had been checked by this time and checked out just fine. No more warranty, just could not get them to stand behind, it (however, our supplier made it right). Changed from the eternal to a navien and the navien has been in for over two years without a lick of trouble. Not sure If we just got a bad batch (leaks were internal on the heat exchanger, it was hard to even get in there and see the leaking area, but was at a welded joint on all three). Needless to say, I have not, nor ever will install one again. The homeowner originally chose the eternal because of the stainless steel heat exchanger, the one item that kept failing. Anyway, that's my story with eternal tankless. Wishing you the best of luck with your situation.

PS, I searched the web for days back then trying to find other people that had problems of the same nature with the eternals, but came up empty handed. I believe they may be a great product, but had to stay away from them because of the personal experience I had with them. Aside from the fact that I did use dielectrics on the first unit (my bad, I admit) I did not use them on the second two, and the rest of the install was above and beyond manufacturers install instructions. Yet they still leaked internally. Hope you can get them to stand behind the warranty one way or the other, but if they don't, I would suggest using a different brand. Maybe look into Navien, or go with your plumbers other product that they recommend. Good luck. Take care.