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BillyHvac
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22116
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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Hi guys. I have the EXACT same issue, Lennox furnace, retro

This answer was rated:

Hi guys. I have the EXACT same issue, Lennox furnace, retro fit with EGC1, same symptoms. I'm even in Alberta as well.

Now, I've removed my heat probe and sanded it down shiny and buffed it with steel wool (reccomended by service man). But I have had no luck yet. I have two objects with ceramic bases. I understand the one on the far left (5th burner in line to ignite) is the "heat probe". The other should be the igniter right?
The service man told me "DONT TOUCH THE IGNITER! It'll span if you look at it the wrong way". But the "Customer" above says he has two heat probes??!!

Maybe the ceramic base I see on the right (1st burner to ignite) is the other heat probe? If so, where is the extremely fragile igniter?
Hello,

My name is Billy

Do you have a different model number other than the LB number?

Customer: replied 3 years ago.
80MFG2-45/60/75-6

There are many 80MFG2- numbers. Are these model numbers?
Thank you.

The main differences between ignitor that should not be touched and sensors are that:

Sensors have (1) wire to them.

Ignitors have (2) wires

But you have the egc board which should have an orange or black spark plug type wire connected to the board on a round short tower.

Is that correct?

Customer: replied 3 years ago.
Correct, it is Grey, "7mm high performance silicone suppression cable" is printed on the side.
terrific....you do not have a ignitor that must be hamdled carefully. You have spark ignition instead of glow rod.

Those look like this:

Hot Surface Ignitor with 5-1/4" leads

You can clean everything else with steel wool that you see.

Can you try this now?
Customer: replied 3 years ago.
Yes, I can attempt this now. I will remove the "Spark Ignition" device with the aforementioned "spark plug style" wire and clean it with sand paper/steel wool. I will respond with results of test after.
Thank you...standing by

Customer: replied 3 years ago.
Some progress, test showed flame preset for 2 minutes. Much longer than before. But sadly the "probes" failed to reach their white hot state in time and the gas flow stopped. It tried again to light but was not sustained for any measurable time frame.

FYI: I also cleaned the out-let if each burner with steel wool. Unrelated probably but there it is..

Attempt cleaning again?

Ok,

so we do get ignition (flame) but it is timing out ?

What is average time of present flame.

Customer: replied 3 years ago.
2nd test flame sustained for 1:25 (m:ss)

Thank you.

And did main blower kick on to cool exchanger?

Customer: replied 3 years ago.
Negative on main blower for circulation.
Thank you.

Does this system have ac installed?

Customer: replied 3 years ago.
Negative for A/C
Thank you.

In the furnace where the thermostat wires attach....there is R, W, G, Y.

Do you see the R and G terminals?

Customer: replied 3 years ago.
Yes

Y - empty
G - empty
R - red wire from thermostat (old style w/ mercury)
C - empty
W - white wire from thermostat.
Great.

I would like you to make a short jumper wire.

I want to connect R to G. You can leave the red and white hooked up. But I want to hook R to G and then tell me if blower fan kicks on.

Customer: replied 3 years ago.
Jumper made between R & G. Fan did not start. I initiated a burn, flame sustained for 1:10, no circulation fan.

I have a brown wire (with a push connector) what is loose, not connected to anything. It is coming from the motor. There are also red, black, yellow & white wires coming from the motor.
Ok,

R to G should have brought on blower.

Based on time I believe you are shutting off on limit and not flame sense.

There should be a capacitor in the blower section



Locate and tell me if only one wire is attached

Customer: replied 3 years ago.
Yes, large & oblong, with two purple wires. Each if these wires is attached to a set of 4 push connect "male" connectors. These sets, are separate. (Almost like the way terminals on a 9v battery are separate) These wires also lead back to the motor.
Thank you,

as long as we have white motor wire to N (com) or (neutral). Black to cool and red to heat,,,the blower should work.

Options are:

The blower is not getting power = bad circuit board
The blower is getting power but has bad capacitor (will usually start with a spin while owered if cap)
The blower is getting power but the blower motor itself is bad.

It appears all your faults are currently related to the blower not kicking on.

Billy
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