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.
Lochinvar ignition trouble
JCattles
Member Posts: 1
in Gas Heating
I have a lochinvar knight kbn150, it was installed in 2006 and ran flawlessly until now.
The boiler fails on ignition, I have removed and cleaned the burner, cleaned the heat exchanger, replaced the flame sensor. I have tested gas pressure with a manometer, I have 9"water at inlet, at outlet side of gas valve I get about 8" negative during purge and then it goes to -2" when fan slows, when gas valve opens I get zero. I can see the spark through the sight glass when it attempts to fire, no flame.
I even got on a ladder and smelled the air exiting the exhaust when the boiler purges after ignition trial and can smell gas. I am dumbfounded, I have fuel, I have spark, but no flame!
All I can think of is the gas valve isn't allowing enough fuel by during ignition, but that seems unlikely and I don't want to drop that much money on a hunch.
Any ideas?
The boiler fails on ignition, I have removed and cleaned the burner, cleaned the heat exchanger, replaced the flame sensor. I have tested gas pressure with a manometer, I have 9"water at inlet, at outlet side of gas valve I get about 8" negative during purge and then it goes to -2" when fan slows, when gas valve opens I get zero. I can see the spark through the sight glass when it attempts to fire, no flame.
I even got on a ladder and smelled the air exiting the exhaust when the boiler purges after ignition trial and can smell gas. I am dumbfounded, I have fuel, I have spark, but no flame!
All I can think of is the gas valve isn't allowing enough fuel by during ignition, but that seems unlikely and I don't want to drop that much money on a hunch.
Any ideas?
0
Comments
-
Call tech
There might be some kind of over heat cut off fuse that might be tripped, or a high limit, I know when those two things happen on some product the gas valve won't even try to start.0 -
What's the error
Whats the error your getting?0 -
Ignition
Verify the proper spark gap. Even if it sparks, the airflow may blow the arc off of the ignitor. You can also adjust the venturi ratio but will need an analyzer to verify the results.
Is this direct vent or Category IV?0 -
Board
Remove the ignition cable from transformer on the board. Attempt to fire the unit. If the spark does not jump to the grounding post replace the board. If it does make the jump. Check the gap on your igniter. After that move towards valve adjustments ect.0
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
- 100 Geothermal
- 156 Indoor-Air Quality
- 3.4K Oil Heating
- 64 Pipe Deterioration
- 917 Plumbing
- 6.1K Radiant Heating
- 381 Solar
- 14.9K Strictly Steam
- 3.3K Thermostats and Controls
- 54 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements