Gas and Oil Home Heating Furnaces - furnace not lighting completely
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sksliwinski
11-25-03, 07:36 AM
I was surfing trying to figure out what was wrong with my 2 year old gas furnace with an electronic ignitor. When I read this response I believe this scenerio is what is happening....
"The little blower must run before it is safe to light the burners. This can be "proven" by a centrifugal switch in the motor or by an air pressure sensor (and possibly in some other way.) Once this has happened, the control board lets it run for 10 to 20 seconds to purge any possible fuel from the combustion chamber. Then it will allow the furnace lighting sequence to take place. Again, this sequence varies. If the gas valve opens the lighting of the burners must be proven or the board will shut down the gas valve and retry. After several tries, the board will lock down and stop trying to fire the furnace. "
Our furnace will heat to proper temps for a few days straight and then have trouble "lighting". This is a weird little quirk, but if I take an air pump and blow some air in when the electronic ignitor gets red hot and stimulates the "fire" to ignite all the burners it will help the furnace to light. I live in the Northern Il and cannot rely on this method all winter and am a new homeowner and not "experienced" in the ups and downs of homeownership. Please help me, is there something I can clean or do to try and fix this before calling in the professionals? Also if cleaning might work, any hints on what to and not to use to do this? Compressed air? Wire brush? Cleaning solutions? I appreciate any help you can offer.
Thanks.
Sharon... the newest homowner on the block
:confused:
"The little blower must run before it is safe to light the burners. This can be "proven" by a centrifugal switch in the motor or by an air pressure sensor (and possibly in some other way.) Once this has happened, the control board lets it run for 10 to 20 seconds to purge any possible fuel from the combustion chamber. Then it will allow the furnace lighting sequence to take place. Again, this sequence varies. If the gas valve opens the lighting of the burners must be proven or the board will shut down the gas valve and retry. After several tries, the board will lock down and stop trying to fire the furnace. "
Our furnace will heat to proper temps for a few days straight and then have trouble "lighting". This is a weird little quirk, but if I take an air pump and blow some air in when the electronic ignitor gets red hot and stimulates the "fire" to ignite all the burners it will help the furnace to light. I live in the Northern Il and cannot rely on this method all winter and am a new homeowner and not "experienced" in the ups and downs of homeownership. Please help me, is there something I can clean or do to try and fix this before calling in the professionals? Also if cleaning might work, any hints on what to and not to use to do this? Compressed air? Wire brush? Cleaning solutions? I appreciate any help you can offer.
Thanks.
Sharon... the newest homowner on the block
:confused:
mattison
11-25-03, 08:04 AM
If you have an air prover switch you can try removing the rubber tube and cleaning it out and where it connects to the furnace.
It's always a good idea to have a pro clean and safety check your furnace at least once a year. Most good companies chrage under $100.00 .
It's always a good idea to have a pro clean and safety check your furnace at least once a year. Most good companies chrage under $100.00 .
Narroc
11-25-03, 09:37 PM
Sounds like the sensor which senses that the flame is going to needs a clean.
A bit of Fine sand paper rubbed up and down the wire where the flame touches the probe, TURN the power of before trying this. Propably has a bit of crud on it.
Be careful you don't bent the wire as it will be brittle and can break.
Alternatively go buy a new one.
A bit of Fine sand paper rubbed up and down the wire where the flame touches the probe, TURN the power of before trying this. Propably has a bit of crud on it.
Be careful you don't bent the wire as it will be brittle and can break.
Alternatively go buy a new one.
Sharp Advice
11-26-03, 07:26 PM
Hello Sharon. Welcome to the Heating & Cooling topic & our Do It Yourself Web Site.
Based upon the problem description, chances are the prover element and or flame sensor element is dirty, defective or has a poor electrical connection.
Correctional methods for this condition and several others are provided below.
Most likely part to cause this type of problem is the flame sensor. The flame sensor is an element device usually located on the burners. It's a round sensor that has leads extending from it.
Cleaning the element is a simple matter of using a fine grit piece of sanding paper or steel wool. The part may have to be removed to accomplish this task. The connection points of this device should also be checked to insure a good clean connection.
If cleaning this part does not resolve the problem, replacing it should. However, it may not. Which indicates there could be any number of other problem possibilities.
When the unit is in a lockout mode, try unplugging it for 5 minutes, then plug it back in and retry. Below is a detailed list of additional information which may apply.
Electronically operated and controlled appliances often require several tests on several componets to determine the exact cause of a problem. The procedures and methods vary and at times can become rather complexing. Be aware that only your heating contractor may be able to resolve the problem.
Listed below are a few of the potiental and or possible causes for the problem description you provided:
If the pilot lighting system has an electronic sparker that lites the pilot flame, and there is no sparking, the sparking element and or electronic module are the most likely defective parts. Clean both the sparker and pilot assemblies first and retry.
Also check for a good electrical connections, etc. to the sparking device, spark module and the pilot flame sensor. If the pilot flame is lighting but the burners fails to lite, a poor electrical connection could be the problem.
The wire that should be cleaned is usually green in color and attached to the sparker module. The other end of this wire will be attached to the furnaces frame.
Be sure the terminal connection is clean and free of any rust and or corrosion. Wire brush or use sanding paper to clean the effected area, then reattach the terminal end exactly as you found it prior to removal.
The pilot flame sensor sends a signal to the main electronic sparking module or control circuit board that a pilot flame is established. The pilots flame will be heating the sensor element directly. If the sensor is dirty, clean it as described below.
Once the signal is received at the main spark module, the main module allows the gas valve to open, sending gas to the burners. If the signal is not sent or recieved, the module will not allow the burners gas valve to open. Therefore, either no burner flames or the burner flames will cycle on and off intermittently.
Below is a list of some of the possible problems and solutions for heating appliances using a hot surface type ignition system. Pick and choose which type, problem or condition applies to the heating appliance you have.
Defective Glowing Hot Surface Ignitor:
The glow ignitor may glow but just be too weak to allow current to continue to flow to the magneto coil and other parts it supplies current to.
The glow ignitor may not be functioning. If it fails to glow, chances are it's burner out. Replacing the Glow Ignitor {Hot Surface Ignitor} may solve the problem.
The main computer circuit board also controls and regulates functions of the heater. It too may have a defective componet.
Defective Solenoids:
The solenoid is inside the body of the gas valve body. Solenoids also supply voltage to a glow ignitor, {if applicable} gas to the pilot flame, {if applicable} main burner gas and or other parts and componets within the entire electrical loop.
Defective Gas Valve:
Remove entire unit as an assembly. Take the entire assembly to your local appliance parts store for testing. Gas valves are not repairable. Replacement is the only option, if defective.
CAUTION:
Do Not attempt to repair the gas valve.
This is a NON repairable item!
The ideal method for determining if either the solenoid, gas valve, gas valve parts, electronic parts or componets, circuit boards or other componets are defective, is to remove the item or items.
Take the entire assembly and or componets to the local retail appliance parts store or heating appliance dealers retail store and have the entire assembly and or parts inspected and or tested, as needed.
Flame Sensor:
This part is located on the burner or near the pilot assembly. If it's defective, it will cause the gas vale to shut down or not function at all or cause the problem your describing.
The flames sensor element, is the part which the pilot flame heats once a pilot flame is established. Cleaning the flame sensor element with fine grit sanding paper or steel wool may solve the problem.
Not all furnaces have a seperate flame sensor element. If your heater is equipped with one, insure the flame sensors element is connected securely and correctly in the pilot assembly, is being heated by the pilots flame, is properly connected to the computers module or spark module and that either or both module is in turn grounded well and correctly.
If the furnace has a power venting system, a vacuum leak can cause the problem as well as moisture in the hoses, defective switches, controls or sensors. A blocked or restricted flue vent to the outside may be all or part of the problem.
FYI:
The do-it-yourself person can test some of these parts yourself using a voltage tester, continuity tester or an ohm meter. However, do not rely totally and solely on any of these tests to determine if the part or componet is functioning correctly.
TIP:
The only positive proof any part is functioning correctly, is to carefully remove the part or parts you suspect to be the potential culprit, and have the local appliance parts store person test it or check it. Appliance parts dealers carry replacement parts for all appliances and are listed in the phone book under appliances.
Additional Suggestions:
Read the manufacturers online web site for product information, problem possibilities, causes and solving methods, part locations, disassembly, reassembly methods, repair procedures and instructions, pictorials and schematics which may be available.
An excellent source for original replacement parts is your local retail appliance parts store, the local heating dealers and agents retail part stores. Bring the make, model and serial numbers. The info will help to determine the possible problem causes.
Heating Agents & Appliance part stores test and stock replacement parts for almost every heater brand. The locations for the dealers, agents and retail part stores are listed in the phone book.
To save time, read the existing questions in this form and those in the heating & cooling forum on heater problems using electronic ignitions.
In doing so you're bound to find the same or similar problem asked. The reply or replies contained within the question will be all of the possbile solutions.
If you need further assistance, use the REPLY button to add any additional information or ask additional questions after attempting the correctional method or methods offered.
Regards & Good Luck. Sharp Advice. TCB4U2B2B Company Enterprises. Web Site Host, Forums Monitor, Gas Appliances Topic Moderator & Multiple Forums Moderator. Energy Conservation Consultant & Natural Gas Appliance Diagnostics Technician.
Personal Reminder:
Buckle Up & Drive Safely.
"The Life You Save, May Be Your Own."
Based upon the problem description, chances are the prover element and or flame sensor element is dirty, defective or has a poor electrical connection.
Correctional methods for this condition and several others are provided below.
Most likely part to cause this type of problem is the flame sensor. The flame sensor is an element device usually located on the burners. It's a round sensor that has leads extending from it.
Cleaning the element is a simple matter of using a fine grit piece of sanding paper or steel wool. The part may have to be removed to accomplish this task. The connection points of this device should also be checked to insure a good clean connection.
If cleaning this part does not resolve the problem, replacing it should. However, it may not. Which indicates there could be any number of other problem possibilities.
When the unit is in a lockout mode, try unplugging it for 5 minutes, then plug it back in and retry. Below is a detailed list of additional information which may apply.
Electronically operated and controlled appliances often require several tests on several componets to determine the exact cause of a problem. The procedures and methods vary and at times can become rather complexing. Be aware that only your heating contractor may be able to resolve the problem.
Listed below are a few of the potiental and or possible causes for the problem description you provided:
If the pilot lighting system has an electronic sparker that lites the pilot flame, and there is no sparking, the sparking element and or electronic module are the most likely defective parts. Clean both the sparker and pilot assemblies first and retry.
Also check for a good electrical connections, etc. to the sparking device, spark module and the pilot flame sensor. If the pilot flame is lighting but the burners fails to lite, a poor electrical connection could be the problem.
The wire that should be cleaned is usually green in color and attached to the sparker module. The other end of this wire will be attached to the furnaces frame.
Be sure the terminal connection is clean and free of any rust and or corrosion. Wire brush or use sanding paper to clean the effected area, then reattach the terminal end exactly as you found it prior to removal.
The pilot flame sensor sends a signal to the main electronic sparking module or control circuit board that a pilot flame is established. The pilots flame will be heating the sensor element directly. If the sensor is dirty, clean it as described below.
Once the signal is received at the main spark module, the main module allows the gas valve to open, sending gas to the burners. If the signal is not sent or recieved, the module will not allow the burners gas valve to open. Therefore, either no burner flames or the burner flames will cycle on and off intermittently.
Below is a list of some of the possible problems and solutions for heating appliances using a hot surface type ignition system. Pick and choose which type, problem or condition applies to the heating appliance you have.
Defective Glowing Hot Surface Ignitor:
The glow ignitor may glow but just be too weak to allow current to continue to flow to the magneto coil and other parts it supplies current to.
The glow ignitor may not be functioning. If it fails to glow, chances are it's burner out. Replacing the Glow Ignitor {Hot Surface Ignitor} may solve the problem.
The main computer circuit board also controls and regulates functions of the heater. It too may have a defective componet.
Defective Solenoids:
The solenoid is inside the body of the gas valve body. Solenoids also supply voltage to a glow ignitor, {if applicable} gas to the pilot flame, {if applicable} main burner gas and or other parts and componets within the entire electrical loop.
Defective Gas Valve:
Remove entire unit as an assembly. Take the entire assembly to your local appliance parts store for testing. Gas valves are not repairable. Replacement is the only option, if defective.
CAUTION:
Do Not attempt to repair the gas valve.
This is a NON repairable item!
The ideal method for determining if either the solenoid, gas valve, gas valve parts, electronic parts or componets, circuit boards or other componets are defective, is to remove the item or items.
Take the entire assembly and or componets to the local retail appliance parts store or heating appliance dealers retail store and have the entire assembly and or parts inspected and or tested, as needed.
Flame Sensor:
This part is located on the burner or near the pilot assembly. If it's defective, it will cause the gas vale to shut down or not function at all or cause the problem your describing.
The flames sensor element, is the part which the pilot flame heats once a pilot flame is established. Cleaning the flame sensor element with fine grit sanding paper or steel wool may solve the problem.
Not all furnaces have a seperate flame sensor element. If your heater is equipped with one, insure the flame sensors element is connected securely and correctly in the pilot assembly, is being heated by the pilots flame, is properly connected to the computers module or spark module and that either or both module is in turn grounded well and correctly.
If the furnace has a power venting system, a vacuum leak can cause the problem as well as moisture in the hoses, defective switches, controls or sensors. A blocked or restricted flue vent to the outside may be all or part of the problem.
FYI:
The do-it-yourself person can test some of these parts yourself using a voltage tester, continuity tester or an ohm meter. However, do not rely totally and solely on any of these tests to determine if the part or componet is functioning correctly.
TIP:
The only positive proof any part is functioning correctly, is to carefully remove the part or parts you suspect to be the potential culprit, and have the local appliance parts store person test it or check it. Appliance parts dealers carry replacement parts for all appliances and are listed in the phone book under appliances.
Additional Suggestions:
Read the manufacturers online web site for product information, problem possibilities, causes and solving methods, part locations, disassembly, reassembly methods, repair procedures and instructions, pictorials and schematics which may be available.
An excellent source for original replacement parts is your local retail appliance parts store, the local heating dealers and agents retail part stores. Bring the make, model and serial numbers. The info will help to determine the possible problem causes.
Heating Agents & Appliance part stores test and stock replacement parts for almost every heater brand. The locations for the dealers, agents and retail part stores are listed in the phone book.
To save time, read the existing questions in this form and those in the heating & cooling forum on heater problems using electronic ignitions.
In doing so you're bound to find the same or similar problem asked. The reply or replies contained within the question will be all of the possbile solutions.
If you need further assistance, use the REPLY button to add any additional information or ask additional questions after attempting the correctional method or methods offered.
Regards & Good Luck. Sharp Advice. TCB4U2B2B Company Enterprises. Web Site Host, Forums Monitor, Gas Appliances Topic Moderator & Multiple Forums Moderator. Energy Conservation Consultant & Natural Gas Appliance Diagnostics Technician.
Personal Reminder:
Buckle Up & Drive Safely.
"The Life You Save, May Be Your Own."
Narroc
11-26-03, 11:10 PM
DON'T use steel wool. You risk the chance of a bit of the 'wool' catching on the sharp bits around the sensor and shorting the sensor. very fine sand paper is better. also watch your hands on the sharp bit that do tend to catch your hand/fingers.