Thermcouper
- Thread starter jabpp4
- Start date
Help Support House Repair Talk:
notmrjohn
Obnoxious Knowitalll
- Joined
- Sep 20, 2012
- Messages
- 251
- Reaction score
- 25
If only 4 years old, your thermocouple probably has a diode attached to it, that may be part that is actually being damaged.
. Not enough air flowing through the combustion chamber to carry the heat up through the flue causes heat build up, which kills the thermocouple. Make sure exhaust flue is large enough, not leaking, unobstructed inside, and runs in as straight and short route thru roof as possible and extends above roof far enough. Also make sure plenty of air is getting to unit to increase air flow, could be plenty of air to keep it burning but not enough to keep thermocouple cool. Larger or another opening into heater compartment, opening should be as low as possible.
Have all your replacements been same brand? Another brand may be more rugged and dependable.
. Not enough air flowing through the combustion chamber to carry the heat up through the flue causes heat build up, which kills the thermocouple. Make sure exhaust flue is large enough, not leaking, unobstructed inside, and runs in as straight and short route thru roof as possible and extends above roof far enough. Also make sure plenty of air is getting to unit to increase air flow, could be plenty of air to keep it burning but not enough to keep thermocouple cool. Larger or another opening into heater compartment, opening should be as low as possible.
Have all your replacements been same brand? Another brand may be more rugged and dependable.
Wuzzat?
Well-Known Member
- Joined
- Jan 20, 2010
- Messages
- 2,471
- Reaction score
- 176
Sounds like they are being severely abused by some as yet unfound root cause.
Measure the voltage output of your thermocouples to check what temps. they are seeing. Common voltages are 25 mV up to 750 mV and when they are turning on a gas valve the voltages may drop to half.
also check the current flow. (Edit: this is nearly impossible without special equipment).
As circuits go this cannot be much simpler.
Measure the voltage output of your thermocouples to check what temps. they are seeing. Common voltages are 25 mV up to 750 mV and when they are turning on a gas valve the voltages may drop to half.
also check the current flow. (Edit: this is nearly impossible without special equipment).
As circuits go this cannot be much simpler.
Last edited:
