York P2MP horizontal furnance bad ignitor?

[Edwardh60]

I have 2 York P2MP systems, one not working. The diagnostic led was not flashing any codes. There is a pressure switch for the led, push it in, the led flashes one time, I guess for "system lock out." The blower works fine. With the thermastat set to auto and heat, the light comes on and the display says the heater is on, however, nothing happens.

I think the flame ignitor might be bad. Comparing the ignitor in the broken system with the one thats working, it looks like a gray covering with diagonal slits is missing. If I buy another ignitor and put it in the broken system, how do you reprogam the system or otherwise get around the system lock out? Does the system reset it self? I have seen other web sites say to turn the power off to the system for no more than 20 seconds, and turn the system back on, to reset. Is that correct?

Thanks for your help.

[Ladyfire3374]

Disclaimer: most of the York gas systems I have worked on have been commercial units.

A typical gas ignition sequence goes something like this:

-there is a call for heating from the thermostat

-the induced-draft fan comes on. This creates an area of lower pressure in the area of the vent.

-the induced draft is "proved" by a pressure switch that measures the pressure. If this switch does not see an adequate pressure drop, the ignition sequence stops here. The ignition module may allow a certain number of attempts before it terminates the cycle.

-The igniter heats up

-The gas valve opens, letting gas flow and ignite.

-The flame must be "proved" to continue the flow of gas. This is done by some type of flame sensor. Again, the ignition module will typically allow several attempts before it terminates the cycle.

From this, you can see that several parts (including the ignition module itself) can prevent heating operation. I'm not telling you this to discourage you, but so you'll know what the possibilities are.

First, since there's no useful code, I would shut off the power as you described to reset the board/module.

Then, the simplest way to check the igniter is to swap the "known good" one into the non-functional unit. If that unit then works, the igniter is your problem. Unfortunately the Law of Old Furnaces applies here, in which parts subjected to lots of heating and cooling (like igniters, pilots, burners and their mounting hardware) become brittle fairly quickly and my break when you try to remove them. Keep this in mind in deciding whether to try the "known good" method.

My suggestion to you is to hold in the door switch and watch your working unit operate several times. This'll show you what it's supposed to do. Then do the same for the non-working unit and see how far into the cycle you get. That'll help you pinpoint where the problem is without just throwing parts at it.

[applianceman18007260692]

post some pictures of the furnace in action

[dilkey]

check to see if you have voltage at the ignnitor on a call for heat, this should be pretty simple, if you have it replace it, if not and you are lost call a hvac co. remember safety first,

[ACtechGUY]

Not all control boards blink trouble codes. some just have a LED to show that they are getting power.

If you have a hot surface ignitor to ignite the flame and it has any hint of white residue or powder on it , The ignitor is bad , or it will be VERY soon. A good ignitor will be totally dark( blackish) in color . the white indicates a spot where the ceramic has cracked due to age and use. Typical hot surface ignitors seem to last about 5 to 10 years, depending on use.

When you install the new ignitor , DO NOT touch the dark colored ceramic with your bare hands . The oils on you hand will cause the new one to fail quickly.

Reseting a "locked out" furnace control is a simple as turning off the 110 volt power. Most Furnce control boards are 'stupid'(no built in memory) and do not retain info after a power recycle. simply turningthe power off and on will let them try to restart normally if they are "locked out"

To see if the furnace is locked out . turn off 110 volt power to heater for 10 seconds. turn heater back on . (make sure thermostat is not on heat when heater is powered back up , some boards will go into a 5 minute delay when powered up with a call for heat). Then turn on heat at thermostat. The induced draft fan (the tiny little fan in the burner section)should start to run. if it does not then you have a #1 a problem with the thermostat or thermostat wiring, # 2 bad induced fan motor, # 3 bad control board # 4 half a dozen other things.

If induced fan runs and ignitor does not glow within 30 seconds, then ignitor is likely bad( especailly if it has white powder on it). It is also possible that the pressure switch is not closing..If the switch does not close then the ignitor will not glow.

If ignitor glows and gas flows and burners ignite and the flames go out.... then clean flame rod.

then......well, I have run out of stuff.

[Edwardh60]

http://i1115.photobucket.com/albums/k547/edwardh60/IMAG0005.jpg

heres a link to picture of the york flame sensor in question. it differs from the one in the unit that is working as there is no spiral gray covering.

http://i1115.photobucket.com/albums/k547/edwardh60/IMAG0006.jpg

this is left side of the ignitor. Maybe it is a newer designed ignitor than the one in the working unit.

How do you get to it to take it out and replace it?

http://i1115.photobucket.com/albums/k547/edwardh60/IMAG0007.jpg

this is the pressure switch that operates the Diagnostic LED.

http://i1115.photobucket.com/albums/k547/edwardh60/IMAG0008.jpg

this is the instuctions to read the Diagnostic LED. When the button is pushed, it flashes once for "System lockout, check furnance."

Please let me know if you can tell from this pictures and descriptions if the ignitor is bad and if so, how do you pull the old one out.

THanks.

[Edwardh60]

Tested the resistance of the ignitor, read 18. Another site said the range should be between 25 and 100 ohms. Would this cause the system to "lock out?" I turned the unit off for 10 seconds, tried it again, nothing happens.

[RegUS_PatOff]

18 should be OK (unless it's actually cracked)

depends on temperature and what type of OHM meter your using .. digital ?

[Edwardh60]

yes, using a digital multi-meter, Cen Tec.

The ignitor does have a line going thru the center of it, looks like it was made that way. My other, working unit has an "older" york ignitor, gray with diagonal spaces thru it. I think the broken unit has a "newer" type ignitor but have not seen one like it researching parts.

My system now is in total lock out. Fan will not run. I have tried powering off the system for 1 second, did not come back on with the fan, tried 15 seconds, nothing happened, tried leaving it off for an hour, nothing. So, cant do much more diagnostic work since system wont come back on at all.

Any suggestions on how to bypass or unlock the system?

[RegUS_PatOff]

some info:

http://www.yorkupg.com/PDFFiles/035-14592-001-A-1202.pdf

http://www.hvacc.net/pdf/upd111507/Residential%20Documentaton/Gas%20Furnaces%20Res/P1/P1DP%200/YS1995-502-95%20lockouts%20and%20rollout%20code%201&5.pdf

[Edwardh60]

Well, gave up and called an HVAC tech. His conclusion was the mother board was bad and estimated a new board would be between $80 to $200. Hate to spend more money on this old unit when I need a new one, but, hopefully can get it running cheap and get thru the winter.

[Ladyfire3374]

It happens.

That's pretty reasonable for a board.

The proprietary (commercial) Carrier stuff I used to work on could get quite expensive, like $900 for a condenser fan motor. Which is why it would get replaced with a generic motor that would only last a couple of years...

Let us know how things work out.

[ACtechGUY]

Ahh... the Infamous 900 DOLLAR , Mystery horse power motor...... used on larger condensers and some chillers.

Lets not forget about the 300 dollar 1/2 hp condenser fan motor with ears. Carrier really sticks it to you with the proprietary motors and controls sometimes .

That being said , York is pretty bad most of he time with their proprietary controls as well . Give me a generic Honeywell or White Rodgers control board any day, they tend to be downright cheap.(by comparison)

[Bobice]

Ahh... the Infamous 900 DOLLAR , Mystery horse power motor...... used on larger condensers and some chillers.

Lets not forget about the 300 dollar 1/2 hp condenser fan motor with ears. Carrier really sticks it to you with the proprietary motors and controls sometimes .

That being said , York is pretty bad most of he time with their proprietary controls as well . Give me a generic Honeywell or White Rodgers control board any day, they tend to be downright cheap.(by comparison)

Just York ? All the manufacturer's are yucky. The best I had a factory trained technician (like that one) tell a customer his ice maker stopped because I used a Whirlpool D/W water valve rather then a Scotsman. Showed the customer that both are made by Eaton valve and put into the various mfg. boxes. Put them side by side, customer saw the only differance $165.00

[dilkey]

i dont agree, before you install a generic fan motor on a carrier unit, you have to know the application, is it controlled by a motormaster,or a p66 control, which needs a oem ball bearing motor only, i work on alot of crac units in chicago only oem motors can handle the amps,if its for comfort cooling only generic is ok.