[encantotom]

wow, that is a little cheaper than tearing into the unit.

good troubleshooting

tom

[Trainer]

Boy, just to share how challenging it is to diagnose long distance, I drove down from Baytown to Sweeny to do an annual service on a heater this morning. First thing I did was remove the radiator cap and check the coolant level (now why didn't I ask Bill to do that?). It was down 1/2 gallon but the overflow tank was full. So either the cap or hose was leaking.

Sure enough after finishing the service, when I fired it up and the tank started to heat up, the tube started to leak. Cut off 1.5 inches, reconnected and fired back up and all was well.

So I second the recommendation to observe the coolant level in the overflow tank rise as the heater warms up and fall as it cools down to ensure the tank stays full all the time.

[bikestuff]

I can hear the poor guy saying....."But my overflow tank said I was full!". Funny!

Rudy, I hope that guy sings your praises! "Man, you did a great service job....I now have a lot more hot water!"

[Chester Stone]

This exact same thing happened to me. However, when I filled the Aqua-Hot tank, I neglected to take some out of the full overflow tank, so when I ran the unit, the overflow tank overflowed all over the place.

[bestgenman]

Bill, look again at Steve's drawing, it is different than the tubes you were refering to wheras Steve's drawing is correct and I believe the return you have pointed is the return from the engine heating circuit. Just so you don't diagnose incorrectly down the road and cost you a bunch of cash!

I noticed my overflow tank not changing level when cool or hot and the cap was also bad however a new cap didn't help. I found the top of the tank neck uneven from old gasket etc. After cleaning with scotchbrite, it began to work properly. The lesson learned is: the cap and overflow cannot have any air leaks!!

Also, be sure to check the PH of your tank mix, it should be well above 7, even up to 9 is fine. If it goes acidic it can ruin the tank. ( another lesson learned from experience!! )

Gordon

[rheavn]

It is a good reminder that the little things that cost very little can be the cause of some big problems.

Congrats Bill on a job well done!!!

[Tony Van Helden]

Hi Guys, I'm a new by on this forum and found Bill's "no hot water" problem of about 4 yrs. ago. I have an 2003 #646 with the same issue. I have gone through the same final steps as Bill and still no hot water. The only thing that I have not done is install a new mixing valve. It looks like I would need to take the burner out in order to get at it. How big of an issue it to do that? Do I need to drain the tank and then remove? The front hot line coming down out the ta k is very hot, but this cools fast past the elbow. There is no hot line leading to the mixing valve. Could this present a plugged up system somewhere? Any guidance here would greatly appreciated.
Tony Van Helden

[Richard]

Tony,

Taking out the burner is easy peasy. Disconnect the computer on the side and remove it from the clip. There are two 10 mm hex head bolts that hold in the burner. One you can see, and the other is 180 degrees away. It will be blind to you. It takes a 10mm socket on an extension to reach them. Once the burner is out, the mixing valve will be readily apparent.



First step is to open and close it a few times. Sometimes they just crud up. If that doesn't work, then take the guts out of a new one, and replace the guts of the old one. You do not have to remove the valve body.

[Trainer]

Tony,

Call me and we can discuss in more detail what Richard has shared with you. It will not take long to determine what to do.

Both Bill and Richard are with me at Bella Terra now. Wish were here with all the Newells.

Rudy. 7 one 3. 8 one 8. 3234

[House Divided]

The Home Depot website has a rebuild kit (just the internal parts) for the Watts valve. Shipping took a few days but i paid $18 and change for the kit and picked it up at a local store. The kit is not stocked in-store.

As Richard said, installation is pretty straightforward.