Kitchen Gas Appliances - Need specs to buy thermocouple.

Hi,

First time for everything. I need to buy a thermocouple for my girlfriends house. I want to buy it at lunch time, central standard time, this Wednesday, the 25th.

Her heater is just a 2 years old. The pilot will light, but then goes out when you release the gaslight button. I have not seen the water heater. Just got a phone-in complaint tonight with this information.

Reliance company. Model 540norto 40 gal gas501
She could not see a millivolt rating on the gas valve.

What should I know before I drive to buy one?
Will hardware store or Home Depot, either, sell them?
Will a universal one work?
What style, mounting bracket, etc?
Are there just 2 or 3 main styles? I could buy them all and just keep the others on hand since I am the worlds most fanatical repair nut. What do you think?
How important is it to match the millivolt requirements to the gas valve? Is there a rule of thumb for millivots?
Tell me other product specific answers to questions I did not ask. lol :p

Hi:Mark

I sure hope I am not too late posting a reply for you.
Maybe you'll catch this prior to going to work. Sure hope so.

Thermocouples are all rated the same. The only difference is the length. Most water heaters will use one 24 inches long. They come in a packet with several different clips to fit just about every intended purpose.

Instructions are included.

The only precaution needed is to be sure you start the new t-couples threads into the mag head of the thermostat by HAND! This is to insure the threads do not enter cross threaded. Doing so might very well damage the mag head.

Next tip is to not overtighten the nut. It should be snugged up but not to the point of screaming uncle...haha

FYI: The mag head is the part the t-couples male threaded end screws into.

Hi Tom,

Thanks for the reply. I have web access during the day so I can check again before I go buy one.

Now then, I like the sound of this job already. Almost sounds too easy. :) But don't tell my girlfriend that. haha.
I will make a note to look for a 24" t-couple.

By this time tomorrow, I will be pounding my chest like Tarzan and grunting that "I did it!" grunt.

Tom is correct 24" for HWT--I just replaced one very easy--mine did not have the thread in style--only a clip retained ir--very easy!

Ok, new 24" t-couple fixed the problem, and she fired right up! Thanks Tom and red.

I was stumped, however, when I could not see how the old t-couple was attached to the pilot mounting bracket inside the tank. I couldn't tell by examining the new one either. This easy job, suddenly looked impossible! I held my tougue out and everything! :rolleyes: :confused: :rolleyes: Then 10 minutes later, I decided to remove the complete burner assembly. Ah haah! :D Better! Now, after I remove it, I can then see that all I had to do was to tug on the t-couple and it would have pulled right out :eek:, without having to remove the complete burner assembly!

Oh well, the more you do, the more you learn, right?

Ya, I pulled my burner out also--still much easier to work on--later!