Water heater thermostat?

[ChopperBill]

WH quit working on electric. Ran the hot water until the gas kicked in and shut the gas down and turned it on electric and grabbed my test meter and went checking. There was no 110 at the element but there is 110 on the high limit switch and on the thermostat (both are on the same assy). Heated it up on gas until it hot to temp. Checked the 110 thermostat again. Has 110 on both sides of the high limit switch and the thermostat. Checked the 12v thermostat assy and it had 12v on both sides of the high limit switch but only 12v on the input side of the thermostat. I surmised that the 110 thermostat assy was bad. I guess mainly because there was not 110 at the heater element when it should. I check the ohms on the thermostat and it had them but cant remember the figures. I have a thermostat on the way (only $19) and ordered the element as a backup ($20 but back ordered). Did I do good in assuming it was the hi limit/thermostat assy?

 

[Rickhansen]

Sounds like a good diagnosis to me.

As a final test to satisfy your curiosity, you could jump the thermostat with an insulated clip lead. Remember to not leave it in place too long or you will continue to heat until the high limit trips. As I recall, the thermostat twists to release from the retainer. I had one that kept overheating, and found it was loose in the retainer and not making good contact with the tank to sense the temperature properly.

 

[ChopperBill]

Thanks Rick. Guess I could have used a jumper wire but now it is 150 miles away in its mountain spot. I fried my very expensive meter by being careless while checking the heater. Good thing I buy them 2-3 at a time for $1.99 at Harbor Freight. Dont think the thermostat can get out of place on my unit it is in a plate with the hi-limit switch and held to the heater with on bolt.

 

[Rickhansen]

Thanks Bill,
A picture is worth a thousand words, right? My water heater experiences were with another rig a few years ago. I know most of the appliances are the same, so was drawing reference of that. The assembly you show looks to be a much better design than the one in my memory, except if you wanted to replace one of the controls.

Too bad to hear about your meter. Checking continuity/resistance while the circuit was hot? Usually that just takes the fuse out. I've got a few decent Flukes that I've had for few years that I'm attached to, and few more "disposable" that wouldn't bother me much to toast.

 

[ChopperBill]

Rick I was checking the voltage when I did the Oops. Popped the breaker on 110v. I have a bunch of the Harbor Freight testers I get on sale. They work as good as my $40 meter. At two bucks each I give them away to friends that don't have one.

 

[ChopperBill]

Well I miss diagnosed this sucker! Put in the thermostat last week. Nada. Had an element but it takes a 1 1/2 socket. Brought one up. Wont fit in the hole in the tin shroud! Found out Lowes has a thin wall socket for that purpose. Also has the elements for half the price of Suburbans!! Good thing these things run on gas too.

 

[nemo45]

We are full-timers and usually shut our water heater off after we shower in the morning. Yesterday we left it on till my wife did dishes and she said the water seemed unusually hot. This morning we turned on the water heater on gas and it would not light or even try to, put it on elec., nothing. So I checked the paper work and found it was still under warranty. Got ready to call Suburban and went outside to get the model and serial no.'s. and noticed the reset buttons and thought what the heck I'll give 'em a try. I felt the buttons click when I pushed them in. So I went inside and tried to light the water heater on gas, bingo, it lit right off. I read in the literature that those resets go when the temp. gets above 180, but what I'm wondering what causes it to get above that temperature. Also, if there is something I need to do keep it from happening again.