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GEAF 12-16-2008 11:27 AM

carrier 58mvp ingnitor part #/ignition problem
Hi all,

I have a 9 year old Carrier 58mvp propane furnace.

The burners do not light at all, at start up, and goes into ignition lockout.

Can anyone confirm that the correct part number for the ignitor is LH33ZS004? Any other generic or improved ignitor that I can purchase?

I've seen code 14 and 34. We hear and see it spool up, and the ignitor starts to glow for about 5 seconds, then it shuts off. Tries 2 more times, then it goes into lockout.

We reset it, and 20% of the time, we can get the burners to light and the furnace works great, until the temperature reaches it's programmed setting, shuts off, but then won't turn back on again when the heat is needed again.

We assume it's not the flame sensor, as we're not getting any flame at all at the burners.

We've cleaned the furnace and the burners thoroughly.

We've checked the green wire at the sheet metal. We actually replaced the end bit, as it looked corroded, but it did not help.

Gas pressure? It is cold now, 20 degrees, so pressure is a possibility, but why would the furnace work part of the time, when we reset it?

We had a heat pump installed 4 months ago, and they did test that the auxillary heat furnace came on, when the temperature is below 35 degrees, and they even cleaned/serviced the furnace during installation. That day was 85 degrees outside, so perhaps gas pressure wasn't an issue.

We'd like to replace the ignitor, before we call out a hvac tech to increase the gas pressure. The ignitor is a light yellow (ceramic?) piece that we can see above the burner box. It does look like it has a burn mark on it.

Any helpful instructions on replacing the ignitor too?

Thanks much, thank goodness for fireplaces!

SKIP4661 12-16-2008 04:49 PM

The part # is correct for this furnace. It may be an ignitor problem. You should check the ignitor for resistance at the plug in the ignitor leads. If it is the ignitor, it is difficult to get at for replacement.
I have seen similar problems caused by the circuit board also.
If the ignitor is not functioning it is not a gas pressure problem.

GEAF 12-16-2008 07:09 PM

Thank you Skip,

I bought the ignitor today, $38 and replaced it. Not too bad of a job, just one screw and the bracket just needed to be bent to remove the old one, and bent back after I put in the new one.

Turned it on. Burners fired right up on the first try! Real test will be late tonight, when the furnace has to start up again to maintain the heat in the house, but I'm pretty confident that we found the correct culprit.

The old ignitor did have black burn marks on the ceramic piece, and the wires looked a bit heat damaged too. The element itself looked pretty good though. Probably why the ignitor would light up for 5 seconds, before shutting off and locking out.

I did drop the old ignitor on the garage floor, when the wires snagged on my shirt. Sure enough the element broke, so they are fragile.

Thanks to this forum for all my research information. I did do all the "free stuff" first, inspecting, cleaning and pushing in plugs, but $38 for a repair can't be beat.

petervand 01-02-2011 12:21 PM

carrier 58mvp
I have a 15 year old propane furnace with a 3500 sq ft . My house is cold. I turn the furnacce on and the house get margainlay warmer. It goes from 13 degrees - 18 in 1 hour. but never gets hotter than that.
It does not go into second phase heat? i think but not sure?
what do i have to do and check?
any help woudl be great,
i live in pemerbton BC so no service si around here...

yuri 01-02-2011 01:20 PM

Do you get snow there or does it just rain all the time.:laughing: LOL. Check the intake and exhaust pipes for blockage. May be partly blocked and not allowing the furnace to go to 2nd stage high fire. Look at the viewing window in the bottom door for error codes. CAREFULLY count the flashes (short and long look similar) and get the code from the sticker on the inside door, may be on the back of it.

petervand 01-02-2011 02:43 PM

hi yuri

no rain just cold ....

thanks we hav:thumbsup:e checked all the intake and output to make sure they are open. :thumbsup: you can feel it drawing air.. but how much should this be?
there is an intake on each floor of this 3500 sq ft home.

how do we know if the furnace does not go into second stage fire?

i am going down to look at the flame.

i put the furnace on and it was 13 degrees 2 hours later it is only 18 degrees. the thermastate is in the living room and upstairs is colder! the house should be at 21 for comfort... URGGGG


yuri 01-02-2011 03:55 PM

Intake and exhaust plastic vent pipes from the furnace that go outside the house. Have you changed your air filter lately?

petervand 01-02-2011 03:58 PM

carrier cold!

just checked the flashes they are as follows- steady yellow light

the intake and exhaust are okay and there are no blockages

it has taken 4 hours for the house to get from 16 - 19 degrees. ? the house is cold.
it is propane driven and costs alot! :eek:

petervand 01-02-2011 04:00 PM

thanks yuri.... not fixed yet but appreciate your help.. what next?

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