Thermocouple life in a Heatilator Fireplace

[joe_pinehill]

I replaced the thermocouple over the summer. We kept the pilot lit once it started getting cooler. The pilot will not stay lit now, and it looks like the pilot thermocouple is eroded or there is a lot of build up on it. Will cleaning the build up sometimes be a fix?. I bought this part on Amazon.

What is the life of a thermocouple. Are you better turning the pilot off when not using the fireplace?

And maybe a dumb question, are all thermocouples equal. Will you get a better quality part from a shop like Mountain View (cost $24) vs Amazon (cost 12)

 

[DAKSY]

You can try cleaning it, but take a close look at the end that's constantly in the flame. If it's compromised in any way, you will have to replace it.
My 12 year-old insert still has the original TC, but there is no guarantee it'll be good when I light it this year. They fail when they fail, & cost generally isn't a factor. Next time you buy one, buy two, just because.

 

[joe_pinehill]

I took the fireplace apart to get a better look at the thermocouple. The top is ablated off. Any suggestions on the best source for a thermocouple?

 

[DAKSY]

Usually, they are available at True Value hardware stores, but take the old one with you to ensure the threads match up.

 

[joe_pinehill]

You can try cleaning it, but take a close look at the end that's constantly in the flame. If it's compromised in any way, you will have to replace it.
My 12 year-old insert still has the original TC, but there is no guarantee it'll be good when I light it this year. They fail when they fail, & cost generally isn't a factor. Next time you buy one, buy two, just because.

thanks for the fast reply. Its not the cost as much as it was a PITA to install the flare nut on the valve. Its a blind installation to start the thread. See the photo I just uploaded. Any advice on where to order the replacement? $12 vs $24 it would not surprise me if they are all made in the same China Great Wall Thermocouple factory.

 

[joe_pinehill]

One more question on installing a new thermocouple. I wrote earlier I replaced the TC in summer. I installed the TC in the pilot bracket, ran the line and then screwed the flare nut in to the valve.

Is it easier to install the flare nut into the valve first?

 

[DAKSY]

Not usually. It's entirely up to you tho.

 

[joe_pinehill]

Has anyone placed a ceramic cover over the thermocouple on a gas fireplace? It seems odd the one i replace only lasted a few months. Or could my pilot be set too high?

 

[DAKSY]

You can check your pilot like this.
Turn the burner off, leaveing the pilot on
With a multimeter set to Volts DC, & the probes on the
terminal block screws labelled TH & TH-TP, you should
have a reading of about 550mV...
If it's over 600, you can damage both the thermocouple & the
thermopile.
Use the pilot adjustment screw to set it to a favorable mV reading.

 

[Sam1942]

How do you get the thermocouple out of a heatilator fireplace: Does it screw out?I can’t get a whench or pliers around it. Sam

 

[DAKSY]

How do you get the thermocouple out of a heatilator fireplace: Does it screw out?I can’t get a wrench or pliers around it. Sam

One end of the TC unscrews from the valve.
The other end is usually held in the pilot assembly by a retainer nut.
IIRC, the wrench size is 3/8"