Kitchen Gas Appliances - strange gas furnace
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02-27-01, 07:58 PM
i have an old chrysler airtemp natural gas furnace that has had electronic ignition added to it. the thermostat is programable and is set for 60 degrees from 10 p.m. to 6 a.m. it then turns back up to 68 degrees. lately it occasionally stopped turning on once it cut back at night. i had a furnace guy check it out (of course it worked fine while he was here) he said thermostat and furnace was o.k. but filters needed changed, which i did but that didn't stop it from acting up, i found out that i could start it anytime it act up by blowing into the chamber where the igniter and manifold is, what's with that? it's too old for any kind of oxygen sensor, isn't it? hope you can help. thanks
Sharp Advice
02-27-01, 08:56 PM
Hi Roy
Your furnace poses a difficult solution because it is an occassional occurrence problem. The condition is not all that uncommon to find as a technican but difficult to pinpoint an exact cauase.
My assumption here is the ignition system lite a pilot flame first, which then heats an element. It's the element that actually allows the gas valve to open and send gas to the burners. The gas is then ignited by this pilot flame.
If this is in fact the type of system on the unit, by your blowing on the flame, the air could be directing the flame onto the flame sensor element just that little bit more which is enough heat to allow the sensor to open the gas valve.
Granted, the above is pure speculation without knowing the exact type of ignition system that was retro fitted and seeing in person the unit.
The flame sensing element could be all or part of the problem. A linted pilot or a poor electrical connection could be the problem.
FYI: The repair person mentioned the filter needing to be replaced as part of good maintenance and not as it being part of the problem.
Your furnace poses a difficult solution because it is an occassional occurrence problem. The condition is not all that uncommon to find as a technican but difficult to pinpoint an exact cauase.
My assumption here is the ignition system lite a pilot flame first, which then heats an element. It's the element that actually allows the gas valve to open and send gas to the burners. The gas is then ignited by this pilot flame.
If this is in fact the type of system on the unit, by your blowing on the flame, the air could be directing the flame onto the flame sensor element just that little bit more which is enough heat to allow the sensor to open the gas valve.
Granted, the above is pure speculation without knowing the exact type of ignition system that was retro fitted and seeing in person the unit.
The flame sensing element could be all or part of the problem. A linted pilot or a poor electrical connection could be the problem.
FYI: The repair person mentioned the filter needing to be replaced as part of good maintenance and not as it being part of the problem.
03-09-01, 01:27 AM
If your hearing a tick-tick-tick or sparking at the pilot burner but it wont catch until you blow on it, it could be that the pilot gas is turned up to high at the automatic gas valve pilot regulator. The gas comes out at too high a velocity, and it wont catch on a weak spark. It is tricky to diagnose. A new ignition wire from the box to the probe can also sometimes help.