Ignitor on natural gas home furnace

[99Eclipse]

Is it possible for an ignitor on a home furnace to run too hot? I had a heating and air company come out to do an inspection on a rental unit so I can renew the certificate of compliance. It has been renewed now but I was also told the ignitor was running too hot and should be replaced before winter otherwise the renters could be, "Dead in the water and without heat." That was several months ago. Since I don't know a whole lot of information about furnaces I tried looking that problem up and found nothing. After talking to someone who was more knowledgeable about heating and air than I am it now sounds like they might not be so trustworthy and were looking for some extra $$$. Either an ignitor works or it doesn't right? Maybe someone here can give me a second opinion.

Furnace is around 20 years old and natural gas. Space that is heated is around 1250 sq ft.

Thanks!

 

[andyd]

Keep looking, ask the office that sent the techs out to conduct the inspection for an explanation? They gave you a piece of paper with numbers on it ? Not up in anybody's face, just a fact finding mission.

 

[Johnny2Bad]

The "smarter" the furnace, the more problems you will have, especially on first startup in fall/winter. But ignitors are just piezo elements ... they are a go/no-go device.

Either it works or it doesn't and needs replacing.

Temperature has nothing to do with it .... it's an electric spark not under compression so no issues lighting as long as it sparks. Think Bar-B-Q lighter or for a really expensive version, the ignitor on a turbo airplane engine. Despite the different uses, they are all exactly the same.

Also a Piezo Ignitor is one of the world's most reliable devices. Problems with these furnaces are in the electronic control modules, and the temperature sensors. Not the piezo ignitor. Also would be curious as to what solution they offered, as this is a very inexpensive part, and simple to remove/install.

 

[jhellwig]

Originally Posted By: Johnny2Bad
The "smarter" the furnace, the more problems you will have, especially on first startup in fall/winter. But ignitors are just piezo elements ... they are a go/no-go device.

Either it works or it doesn't and needs replacing.

Temperature has nothing to do with it .... it's an electric spark not under compression so no issues lighting as long as it sparks. Think Bar-B-Q lighter or for a really expensive version, the ignitor on a turbo airplane engine. Despite the different uses, they are all exactly the same.

Also a Piezo Ignitor is one of the world's most reliable devices. Problems with these furnaces are in the electronic control modules, and the temperature sensors. Not the piezo ignitor. Also would be curious as to what solution they offered, as this is a very inexpensive part, and simple to remove/install.


Furnaces have had hot wire igniters for a long time. They never used piezo electric igniters except maybe for a pilot light but pilot lights went away a long time ago.

 

[KD0AXS]

Your furnace probably has a "hot surface ignitor", which is an electric heating element that glows red hot to ignite the gas. If it's getting too hot, it can indeed fail.

 

[WhyMe]

they usually are not too hard to replace. find out the part number and just buy one as a spare. when it goes bad ,which could be tommorow or 20 years from now, at least you can replace it and not have to wait for a part

they are usually less than $20

 

[StevieC]

We have no insulation in our walls of the 1942 house and it leaks a lot of air so the 98% efficiency furnace we have is running all the time on/off in our house from fall until spring and it's a Silicon-Nitride Igniter and it's about 6 years old. No issues.

Something like this.

 

[4WD]

Mr Holmes can fix you up

 

[StevieC]

Natural Gas here is cheap, insulation like everything else in

is not...

 

[bullwinkle]

They do go bad-and make sure if you replace it yourself, to wear gloves when you handle it. Much like a halogen bulb, the oil on your skin will make it fail prematurely. They glow white hot in operation, there's no such thing as too hot for one (unless it has a hot spot, which would make it die pretty quickly).

 

[99Eclipse]

After examining my furnace which is similar to the rental unit (It is a duplex and I am opposite that side) the ignitor looks similar to the picture on StevieC's post. Now I have something to go off of tomorrow when I look up more info online, and if there is a question I will also see what the heating and air people say about the previous visit. I could also watch my furnace compared to the rental unit now I know what the ignitor looks like. We will see if they were correct or full of it. Anyway, I have a quite a bit more info to help me out. I will check back too. Thanks everyone!

 

[E365]

I had one fail. It would start to glow and you could see a “crack” appear. Pretty easy to diagnose in my case.

 

[Fitter30]

Stevie c has one pictured, if yours is like the one pictured the igniter board is looking for a certain amp draw to open gas valve. Even if turns red it will not open the pilot gas without that amp draw. Like other people have written there not to expensive and not to hard to replace just try not to touch the element with bare fingers the oil on them might shorten its life.

 

[99Eclipse]

I think I will get at least one spare if not more. I have now found a friend of a friend who may be able to help me get the right one and I do bet I can change it fairly easily. Looks like it attaches with just one screw and of course the plug. Can't imagine there is a very high chance of screwing anything else up while doing it considering since I don't have to take anything else off. Seems easy to get to, easy to take off and replace. I'm sure I will remember not to touch it either like they say.