[Shunt]

I'm going to be leaving home in about a week, and I'll be gone for 1-2 months. I live in an area that goes well below freezing during winter, so keeping the furnace going while I'm gone will be important. I'm going to shut off the water and drain the pipes before I leave, but I still don't really want the house to freeze while I'm gone.

I've lived in this house for about 9 years, and I've never changed the ignitor on the furnace. So it's at least that old. It has always worked fine. It's a hot surface ignitor, I'm not sure exactly what style, but I think it's a Carrier furnace. I have a brand new ignitor on hand just in case mine goes out. But now I'm thinking, should I just change it out before I leave? Seems like a no-brainer to just put it in before I leave. But my only fear is that just maybe my new ignitor is a dud and will fail shortly after I put it in, once I'm away from home. Does that happen often?

 

[Shunt]

Model number?

If you can measure the current of the HSI, it would tell you if it's getting a bit weaker. It's very accurate when you have a baseline. You should write it down if you do change it.

The ignitor can be cheap enough. Same with the capacitor for the blower motor if it has one.

However, if it starts up without fuss every time, I wouldn't worry too much. You can record a video and post it to YouTube then link it here. It will let us listen to the startup, and maybe hear anything going on.

Yeah the new ignitor was only $20. And after getting over 9 years out of this last one, I have absolutely zero qualms about changing out a $20 ignitor before it really had to be replaced just to give myself some piece of mind. I don't think I have an amp clamp to measure the high amperage of the ignitor.

Actually I guess it's a Payne Furnace, but basically same as a cheap Carrier apparently.

It's a Payne PG8MAA036070AAJA
The ignitor is a LH33ZS004

Good idea on the startup video. I might do that.

 

[Shunt]

I see 331930-751 for the ignitor. It's not so cheap. While your at it, replace or clean the flame sensor, which is cheap. LH680534

PS. Carrier owns Payne.

I looked up photos of the 331930-751, my ignitor does not look like that. This is what my ignitor looks like, and the spare I got was made by Robertshaw and it was actually a little less than $20.

I cleaned the burners, flame sensor, and vaccumed all the dust out of the furnace about a year and a half ago, so I'm good there.

 

[Shunt]

Get an internet-connected thermostat (e.g. ecobee) and check it every day?

Yeah I have that, and I will. But I'm going to be across the country, in a vehicle, so about all I would be able to do is watch my house freeze in real time, and debate whether I should drive 30 hours home or not to deal with it. And I really don't want to try to coordinate getting a repair man to the house when I'm out of the state.

 

[Shunt]

Those igniters can be very fragile, it's best to not replace unless you have a reason.

Are you saying because of the potential to damage the new one installing it? Is it that common for a brand new one to fail quickly due to mishandling or being defective out of the box?

 

[Shunt]

Ok well I started to realize that the longer I went back and forth about whether to replace it, the less time I'd have running the new igniter while I'm still home to be able to make sure it's working well, so I just went ahead and replaced it. Good for the first start at least. I will probably still record a video of it starting up so you guys can say if anything seems off. Thanks.

 

[Shunt]

Now that you have a new igniter, the board is going to crap out as soon as you leave. Lol

Most likely.

 

[Shunt]

when are you leaving ? stuff like this you do weeks before, so you are there to keep an eye on it. same for car repairs

Probably in about a week. Too late, it's done now. Just decided to get it over with so I have as much time as possible to make sure it's good before I leave. And with the delicate nature of the igniters, no way I'm swapping back to the old one now.

 

[Shunt]

For a large number of ignitors, or any piece of equipment, the failure rate follows the “bathtub curve” shown below, with a higher “infant mortality” rate at the beginning than later on in life. You have to make an estimate, based on the anticipated lifetime of an ignitor, where your unit is along that curve. I wouldn’t replace a piece of equipment that is operating normally and is critical to heating the house, just before going away.

View attachment 679831

Yeah I know this, and that's why I was hesitant to replace it. But I would argue that at over 9 years old (probably significantly more) my old igniter was probably quickly approaching the right side of that curve, and that's why I did want to replace it.

 

[Shunt]

Also just one other thing, I was able to find what I think is the resistance spec of this igniter at room temperature. Seems like it is supposed to be between 40 and 100 ohms.

The new igniter is 62.9 ohms. The old one I took out is 108 ohms. So yeah despite feeling a little leery about replacing a part just before I leave home, I don't trust that old one based on the resistance.

 

[Shunt]

You'd benefit from getting a cheap clamp on multimeter. $30-50 range. There are some that are cat III rated at that price range. You'll want to measure the current at startup and write it down. It'll also be really useful for troubleshooting other parts in the future. No rush on it.

Actually I have a nice Blue Point meter and I swear there I have an amp clamp for it laying around somewhere, just can't find it, so I don't want to buy another. And generally most work I do I don't need to measure amperage over the meter's limit of 10A, so I haven't made finding it a priority.

 

[Shunt]

Yeah I think from a purely technical standpoint it's kind of a good idea to leave a space heater "on" but at a very low temperature setting so the intent is that it won't ever actually run except in an emergency. And I did think about that.

But, from a practical standpoint, leaving a space heater plugged in and "on" in any way when I'm leaving the house for weeks to maybe months? Naw, that doesn't sound good.