Keeprite NG furnace code "fail to ignite"

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Ok, good info.

From what I can find, any of these can cause that alarm:
* Gas is shut-off.
* PCB not sending 24 VAC to gas valve.
* Bad gas valve.

The pressure switch is before the HSI in the Sequence of Operation, so if that didn't make, your HSI wouldn't light-up. So you're good there.

I had to download the Kenmore manual to find this info (it's not in the Keeprite Manuals, for some stupid reason), but you can find it here:


See pages 50-52.

So back to Square One. Is the gas "on", and if so, is the gas valve receiving 24 VAC on the MV terminal 17 seconds after the HSI warms-up?

And just an FYI, when the gas valve does energize, you'll hear it, if you're listening for it. You can also feel it, but it's light.
 
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One other thing.

The Sequence of Operation depends on whether you're using a single, or two-stage thermostat. If you're using a two-stage stat, pull the W2 wire at the terminal strip, otherwise the furnace is going to "see" a High Heat call, which somewhat negates what I've said above.

From top of Page 51:

24VAC signals applied to W1 terminal of FCB.
• Same response as single stage thermostat operation described above except the burners, inducer, and blower will not go to high
heat rate, and High Heat Fan speed unless a W2 signal is applied.
24VAC signal applied to W1 and W2 terminals of FCB.
• Same light−off routine as described for the signal stage thermostat operation except burners light at High Heat rate, the inducer
remains on high speed after ignition, and the FCB will delay High Heat blower operation for the 30−second High Heat Fan
On Delay.
NOTE 6) The FCB responds without delay to the presence or loss of W2 (with W1 constant). W1 & W2 result in high inducer, High Heat
rate, and High Heat Fan speed. W1 only results in low speed inducer, Low Heat rate, and Low Heat Fan speed.
 
Heres 2nd video I just took this morning. You can feel/hear gas valve click. I didnt measure V yet, but appears to be going thru the proper steps up until the control valve. It clicks, waits a few seconds then igniter shuts down.
 
4spdragtop said:
Heres 2nd video I just took this morning. You can feel/hear gas valve click. I didnt measure V yet, but appears to be going thru the proper steps up until the control valve. It clicks, waits a few seconds then igniter shuts down.
Click to expand...

Sounds like the gas valve is kicking-in at both 1:33 and 2:12 (of course I could be wrong), but from what I can see in the Manual it's supposed to do that 4x, then give you a "6+1" code (middle of page 51).

Are you shutting it off (releasing the door interlock), or is shutting down on it's own?

Also, did you do any work on your gas line over the summer? Maybe your line just needs to be purged of air. (Got a couple pipe wrenches? Power down the furnace, and then CAREFULLY AND SLOWLY crack open the union located on the outside of the unit to purge. You'll know when you're done purging, as you'll smell the gas.)
 
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When furnace was installed, it had the old style round thermostat that had mercury level in it. I changed the thermostat to a newer cheap programmable one. So I'm assuming original mercury Tstat was single stage. Not sure of one I installed? I'll chk here shortly.
Will grab VOM also.
Oh, the furnace is shutting down on it's own. I'm holding the door interlock switch down completely. Then releasing it after 2 attempts to light.
ProjectBazza said:
One other thing.

The Sequence of Operation depends on whether you're using a single, or two-stage thermostat. If you're using a two-stage stat, pull the W2 wire at the terminal strip, otherwise the furnace is going to "see" a High Heat call, which somewhat negates what I've said above.

From top of Page 51:

24VAC signals applied to W1 terminal of FCB.
• Same response as single stage thermostat operation described above except the burners, inducer, and blower will not go to high
heat rate, and High Heat Fan speed unless a W2 signal is applied.
24VAC signal applied to W1 and W2 terminals of FCB.
• Same light−off routine as described for the signal stage thermostat operation except burners light at High Heat rate, the inducer
remains on high speed after ignition, and the FCB will delay High Heat blower operation for the 30−second High Heat Fan
On Delay.
NOTE 6) The FCB responds without delay to the presence or loss of W2 (with W1 constant). W1 & W2 result in high inducer, High Heat
rate, and High Heat Fan speed. W1 only results in low speed inducer, Low Heat rate, and Low Heat Fan speed.
Click to expand...

67Dart273 said:
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Click to expand...

ProjectBazza said:
Sounds like the gas valve is kicking-in at both 1:33 and 2:12 (of course I could be wrong), but from what I can see in the Manual it's supposed to do that 4x, then give you a "6+1" code (middle of page 51).

Are you shutting it off (releasing the door interlock), or is shutting down on it's own?

Also, did you do any work on your gas line over the summer? Maybe your line just needs to be purged of air. (Got a couple pipe wrenches? Power down the furnace, and then CAREFULLY AND SLOWLY crack open the union located on the outside of the unit to purge. You'll know when you're done purging, as you'll smell the gas.)
Click to expand...
 
Time to make the call and write the check.
 
I put in a Coleman furnace a few years back, it was suggested to me by my local REA ( HEAT PUMP) cost savings, blah blah ..

It was / is a pos , its one of these modulating things it did something really similar, had it looked at under warranty multiple times.

Friend of a friend is a pretty handy HVAC tech, he came out messed with it a little , flipped t-stat to emergency and knock on wood , hasn't bothered since, been 3-4 years i think
 
When you swapped-out the stat, have you ever had heat since then?

The old T87 stats were indeed single stage, and your furnace can run with a single stage stat just fine, as it has internal logic to change from Low to High, as long as it was set-up properly initially.

When you changed the stat, did you change any wiring, or DIP switches, in the furnace?
 
4spdragtop said:
Oh, the furnace is shutting down on it's own. I'm holding the door interlock switch down completely. Then releasing it after 2 attempts to light.
Click to expand...
It shouldn't do that. As per the Manual, the furnace should make 4 attempts to light-off, and if unsuccessful, give you a "6" code followed by a "1" code (6+1).

You can always run some tape across that door switch while testing. Or, unplug them from the back and jump them out (after turning off the power, of course!).

From the Manual:

Heating Request with Gas Shut Off:
24 VAC signals applied to W1 terminal of FCB.
The FCB will attempt 4 cycles for ignition then go to soft lockout for 3 hours, and then try for
ignition again as long as the heat call remains. Power reset will clear lockout.
• Inducer motor turns on at high speed.
• Following a 15 second prepurge delay after the low pressure switch closes, the ignitor begins
warm up.
• The ignitor glows red−hot for 22 seconds, then turns off. The FCB flashes error code 6.
• The ignitor stays off for 17 seconds, then begins to warm up again.
• The ignitor glows red hot for 22 seconds then turns off. The FCB continues flashing error code
6.
• The ignitor stays off for 17 seconds, then begins to warm up again.
• The ignitor glows red hot for 22 seconds then turns off. The FCB continues flashing error code
6.
• The ignitor stays off for 17 seconds, then begins to warm up again.
• The ignitor glows red hot for 22 seconds then turns off. The FCB proceeds to soft lockout.
Stops flashing error code 6, and begins flashing error code 6 + 1.
 
Everything furnace/thermostat wise has worked properly for 14 years(furnace) and 2-3 years(thermostat). I wired the tstat as per tstat instructions. One wire unused...like an ECU lol.
ProjectBazza said:
Sounds like the gas valve is kicking-in at both 1:33 and 2:12 (of course I could be wrong), but from what I can see in the Manual it's supposed to do that 4x, then give you a "6+1" code (middle of page 51).

Are you shutting it off (releasing the door interlock), or is shutting down on it's own?

Also, did you do any work on your gas line over the summer? Maybe your line just needs to be purged of air. (Got a couple pipe wrenches? Power down the furnace, and then CAREFULLY AND SLOWLY crack open the union located on the outside of the unit to purge. You'll know when you're done purging, as you'll smell the gas.)
Click to expand...

ProjectBazza said:
When you swapped-out the stat, have you ever had heat since then?

The old T87 stats were indeed single stage, and your furnace can run with a single stage stat just fine, as it has internal logic to change from Low to High, as long as it was set-up properly initially.

When you changed the stat, did you change any wiring, or DIP switches, in the furnace?
Click to expand...

ProjectBazza said:
It shouldn't do that. As per the Manual, the furnace should make 4 attempts to light-off, and if unsuccessful, give you a "6" code followed by a "1" code (6+1).

You can always run some tape across that door switch while testing. Or, unplug them from the back and jump them out (after turning off the power, of course!).

From the Manual:

Heating Request with Gas Shut Off:
24 VAC signals applied to W1 terminal of FCB.
The FCB will attempt 4 cycles for ignition then go to soft lockout for 3 hours, and then try for
ignition again as long as the heat call remains. Power reset will clear lockout.
• Inducer motor turns on at high speed.
• Following a 15 second prepurge delay after the low pressure switch closes, the ignitor begins
warm up.
• The ignitor glows red−hot for 22 seconds, then turns off. The FCB flashes error code 6.
• The ignitor stays off for 17 seconds, then begins to warm up again.
• The ignitor glows red hot for 22 seconds then turns off. The FCB continues flashing error code
6.
• The ignitor stays off for 17 seconds, then begins to warm up again.
• The ignitor glows red hot for 22 seconds then turns off. The FCB continues flashing error code
6.
• The ignitor stays off for 17 seconds, then begins to warm up again.
• The ignitor glows red hot for 22 seconds then turns off. The FCB proceeds to soft lockout.
Stops flashing error code 6, and begins flashing error code 6 + 1.
Click to expand...

20231009_115343.jpg


20231009_115434.jpg


20231009_115443.jpg
 
Good info, thanks!

So it's not your stat, or wiring....

So back to gas and voltage. Are you absolutely certain you have gas at the furnace? Also, have you checked voltage at the MV terminal on the gas valve?

Your HSI looks good (usually they either work, or they fail completely), and based on experience (in my opinion) I feel it should light-off the gas, but I've been wrong before. (And who knows? Maybe your gas supplier has an additive that has raised the ignition point of your NG, I don't know.) Thankfully the P/N on that plug is used by many other manufacturers, and it's a pretty cheap part, so as much as I hate "parts swapping", if you can locate a new one, by all means- have at it!

Last thing I can think of- maybe your gas valve is making, but you're not getting any gas output (bad gas valve). This is easy to measure if you have the right tools (pressure S/B around 3.5" W.C. on the gas manifold), but not too many people own a gas manometer.
 
Well, dunno why, but after 3rd or 4th cycle it lit. I didnt measure voltage at all, as it lit this time.
Hard to believe but at 14 years old this furnace is well beyond its 1/2 life....
Now to find a filter on Thanksgiving lol
Thanks all, I appreciate it. I'm not totally comfy messing with NG, but i figured we were "safe" as there is was no smell and nothing obviously was broken.
Irony is there are incentives here in Ontario(gov grants) to install a heat pump as a primary heat source as long as you have backup heat(furnace). But our 14yr old furnace is not on the "approved" list lol. So in order to get $6500 towards a heat pump I have to buy a new furnace lol.
Thanks all
 
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Steve this big push to heat pumps is BS. ALL heat pumps, unless they are in Tucson, require backup/ emergency heat, for two reasons----for additional heat during the temp range that the heat pump cannot produce enough, and full backup (no heat pump) for when it gets really cold or when the heat pump develops a problem. Since "they" are pushing for all electric, that means ELECTRIC backup heat.

So far as your problem, I would worry about WHY. WHY did it decide to quit, and why did it decide to start working?
 
I am NOT sure why the initial "no start", but the bride mentioned this was 1st fire up of the season. So that is new info. This last attempt, I closed the manual valve and reopened it. It was in open position.
Turning the control valve off/on a few times maybe helped with the *** kicking...
I agree with finding what went wrong, I'll try to source a spare igniter cheap...anything I've found is $80 range, and the 2 stage valve is around $600 lol.
Heat pumps from what I gather have improved drastically over the past few years. Anyone I know that has one likes them, but yes there are stipulations here to have another means of heat, whether ng/elec. Not sure if wood applies?
The grant essentially would "give" us a new heat pump, up to $6500. But we would have to upgrade to a new furnace. I've no idea what the cost is for new NG furnace. The current one I believe around $4k??
The new heat pump has 2 benefits(for us anyway), is that it will replace our 40 year old ac unit(drastic efficiency increase) and will heat us more efficiently (I believe).
Options...keep everything as is including our crossed fingers lol
- pay $3-4k(maybe more) for new ac and keep 13 yr old furnace...
- new heat pump(gov grant) and we pay for new furnace, not sure what they charge now ??
Theres other incentives, new windows insulation etc in this program. I took advantage of it initially in 09 with the current furnace, new windows and insulation. Only windows Dad and I didnt do were the basement ones. I may look into it this time around.
Thanks for all the help folks!
CFD244 said:
Glad that you are back in business.
Click to expand...

ProjectBazza said:
Great news! Just had to give 'er the old kick in the ***, huh?

:lol:
Click to expand...

67Dart273 said:
Steve this big push to heat pumps is BS. ALL heat pumps, unless they are in Tucson, require backup/ emergency heat, for two reasons----for additional heat during the temp range that the heat pump cannot produce enough, and full backup (no heat pump) for when it gets really cold or when the heat pump develops a problem. Since "they" are pushing for all electric, that means ELECTRIC backup heat.

So far as your problem, I would worry about WHY. WHY did it decide to quit, and why did it decide to start working?
Click to expand...
 
4spdragtop said:
I am NOT sure why the initial "no start", but the bride mentioned this was 1st fire up of the season. So that is new info. This last attempt, I closed the manual valve and reopened it. It was in open position.
Turning the control valve off/on a few times maybe helped with the *** kicking...
Click to expand...
We run into this on commercial buildings quite often, and it takes a while for the Techs to switch their brain over into the heating mode in the Fall and recall that the gas line(s) may be low on gas pressure, or have some air in them. Once they remember this (need to purge on rooftop units), the No Heat calls tend to go down.

This could be nothing more than your gas regulator has taken a "set" over the summer, and it's gotten used to supplying "x" amount of gas for the stove, water heater, or whatever. Now that you want "comfort" (furnace) heat again, it has to adjust (open) more, and as we all know, it gets harder to move the older you get.

Regardless, you'll remember this next year, right?
 
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