Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
Thermocouples
Dave_23
Member Posts: 190
in Gas Heating
Thermocouples
Hi there. I have a WM EG-35 steam boiler, standing pilot. Over the
weekend I replaced my second 30 millivolt thermocouple in two years.
The boiler was installed in 2001, and the stock WM-supplied thermocouple
which came with the boiler lasted about 9 years. Subsequently, I replaced
it with a Universal Honeywell Thermocouple (sorry, Honeywell...),
purchased for about $10 at the local hardware store, which lasted about
12 months. I replaced it again over the weekend with my backup spare
(another HW Universal). Any suggestions for makes and models of heavy
duty 30 mV thermocouples that may last few more years or that won't burn
out as quickly? Note 1: WM no longer supplies their original
t'couples. Note 2: The form factor of the WM t'couple mount is
screw-in, same as the HW universal. Any suggestions will be much
appreciated. Dave.
<a href="http://www.heatinghelp.com/forum-reply/1190016/Thermocouples">Reply</a>
Hi there. I have a WM EG-35 steam boiler, standing pilot. Over the
weekend I replaced my second 30 millivolt thermocouple in two years.
The boiler was installed in 2001, and the stock WM-supplied thermocouple
which came with the boiler lasted about 9 years. Subsequently, I replaced
it with a Universal Honeywell Thermocouple (sorry, Honeywell...),
purchased for about $10 at the local hardware store, which lasted about
12 months. I replaced it again over the weekend with my backup spare
(another HW Universal). Any suggestions for makes and models of heavy
duty 30 mV thermocouples that may last few more years or that won't burn
out as quickly? Note 1: WM no longer supplies their original
t'couples. Note 2: The form factor of the WM t'couple mount is
screw-in, same as the HW universal. Any suggestions will be much
appreciated. Dave.
<a href="http://www.heatinghelp.com/forum-reply/1190016/Thermocouples">Reply</a>
0
Comments
-
Thermocouple adjustment
After discussing the matter of premature thermocouple failure with WM,
Honeywell and Johnson Controls, the following has been suggested: The
premature failure I'm experiencing may be caused by overheating the
thermocouple. The techs I spoke with indicated that the thermocouple
probe may be protruding too far into the pilot flame, causing
overheating. Question: How far should a standing pilot thermocouple protrude into the flame? Just barely, 1/8 inch, 1/2 inch, as much as possible, etc? The tech from JC seemed to think "just the tip." Thoughts and suggestions?0 -
thermocouple stuff
Just type in, Thermocouple Testing Procedure in the search site area and you'll find everything you'll need to know. Tim McElwain, the host of this sub category, wrote the piece of info. You came to the right place.
0 -
Dave,
If you have any problem finding the procedure let me know. The thermocouple you need is a Johnson/BASO K16LRA-36 which is a high temperature corrosion resistant thermocouple.
The thermocouple should be 1/2' to 3/8" into the flame and the flame should be a soft blue flame not roaring or lifting and the tip of the thermocouple should be dull red not "cherry" red.0 -
Thermocouple adjustment
Thanks for the info! Now, I just have to find a distributor in our area for the Johnson/Baso item. A Google search returns no useful info...0 -
What is your
location?0 -
Thermocouple adjustment
Detroit, MI 48201. Anywhere within 10-15 miles is ok.0 -
Thermocouple adjustment
Found a place - Young Supply, near my office. I'll be ordering the K16RA-36. No one could supply or identify the "L" in the reference to K16LRA-36. Thanks for the assistance! Dave0 -
Sorry the K16RA
is correct I do not know how I typed the "L" in there. Well after all I am 70 years old! Just a senior moment.0 -
Thermocouple adjustment
No problem. The K16RA looks like just the ticket. Had I been on vacation during my recent pilot light outage/thermocouple failure, I'd have had a real mess on my hands, with outdoor temps below freezing.
It never occurred to me that a thermocouple could fail so quickly. From now on, I guess I'll have to have the neighbors check the indoor temp as well as collect mail and papers.0 -
The truth is a
thermocouple should last 8 to 10 years.
So now that we have a durable thermocouple on the way you need to have a professional do a combustion test on your equipment. The failure of the thermocouples is a warning on a combustion issue which now needs to be addressed.0 -
Thermocouple adjustment
What is the exact procedure for conducting a combustion test and what data will be collected and reported? I will attempt to do this myself, however, I'd like some detailed info so I can interview and select a qualified boiler professional or company. Thanks, Dave.0 -
Thermocouple adjustment
I meant to say "I will NOT attempt to do this myself." Sorry for the confusion...Dave0 -
The reason for the
combustion test is to determine if the system if firing correctly. The fact that thermocouples are being burned up tells me something is wrong. If you have gone through my Thermocouple Test Procedure that is available here then the next step is combustion testing.
The test will measure CO2, O2, Flue Gas Temperature, draft, and CO (Carbon Monoxide). A good combustion analyzer (Electronic) will be able to determine these parameters. Then the technician can determine from there a number of things.
There are many things that can affect operation of your system such as:
1. Not enough air for combustion
2. Incorrect venting
3. Undersized gas piping
4. Airborne contaminants, laundry room nearby, dryer operation
5. Over or under fired boiler
and many more, a professional combustion/gas technician will be able to determine any problems which need to be corrected.0 -
Thermocouple adjustment
Tim,
The Johnson Controls K16RA works great. I could tell right away it's heavier duty and more substantial than the Honeywell Universals. One issue that I did have to resolve (with a little ingenuity) was figuring out how to adjust the installed height of the K16 relative to the pilot flame. When installed as supplied into the stock WM pilot/TC mount, the K16 protruded a about 1/4 inch too far up into the flame. (Note: The Honeywell Universal did the same). What I did was install a thin hardended steel metal spacer ring over the TC "shoulder" to hold it off a bit from the flame to ensure proper positioning. Only thing I can conclude is that the stock WM TC must have been shorter in length or had a different form factor. Rest assured that the K16 TC is securely installed and is not "jury rigged." I believe my solution was reasonable, given the situation. Result: Secure mount, proper orientation of TC in the pilot flame; dull, dark orange glow from the tip to about a 1/2 inch down. Thanks again for your assistance.
-Dave0 -
Dave that is great
be sure and follow my advice and have professional take a look at the unit to perhaps fine tune it to eliminate other issues0
This discussion has been closed.
Categories
- All Categories
- 86.3K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 422 Carbon Monoxide Awareness
- 90 Chimneys & Flues
- 2K Domestic Hot Water
- 5.4K Gas Heating
- 99 Geothermal
- 156 Indoor-Air Quality
- 3.4K Oil Heating
- 63 Pipe Deterioration
- 916 Plumbing
- 6K Radiant Heating
- 381 Solar
- 14.9K Strictly Steam
- 3.3K Thermostats and Controls
- 53 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements