Lennox Don't Work In The Cold

There is something charming about nursing along an old clangy standing-pilot classic for a long time. Mine was vintage 1981 and I didn't replace it until 2010.

But, you know, the new one is a whole lot quieter, and the house stays so much more comfortable, without the big temp swings of the old one, and the more heat extracted from less gas part is nice too.

I think the biggest mistake of that kind that I've made, looking back, was keeping an old late 20th century fridge going because it was cheaper to fix than replace. When I finally replaced it with a modern one (around 2011? maybe), I think the difference in energy efficiency paid for it that year (or nearly so). Kicking myself for not biting that bullet several years earlier.

 

I have a long short list of things I'd like to add / replace that's years old and waiting for approval from the accountant. No least of which is a Drew / Opus toy passthrough which I might be byteing on early even without the accountants say so.

 

If I had only changed that fridge several years earlier, I could have bought several fridges' worth of other fun things with the electric bill savings.

 

One item I did for our furnace was to preventatively order - an igniter and a flame sensing rod for our Carrier Gas Furnace. Our unit was 7 years old this year and during our 0 degree weather I thought it would be nice to have spares laying in the base of the furnace cabinet just in case. The cost of these two item didn't total together more than $25 dollars on ebay.

 

I've thought about laying in spares for certain parts, which makes even more sense as I've got two of these furnaces, but I would have guessed wrong about which spares to keep around.

Igniter would have been my first guess, but both of those are a dozen years old now and going strong. I've had to change two condensate traps, one inducer blower, and one gas valve, none of which I would have guessed.

I just looked up igniter life expectancies and there seem to be two types, carbide and nitride, with the latter lasting a lot longer. It seems likely I've got that kind, then, as carbide ones would have been much likelier to fail by now, it seems. Maybe I really should lay in one spare igniter now, for good measure.

I haven't heard of much happening to a flame sensing rod that can't be taken care of by cleaning it.

 

Igniters have improved for furnaces. The silicon nitride igniters have a life expectancy of 7 to 15 years and are very reliable.

The flame rods can be cleaned by fine steel wool but will sometimes go bad simply because the ceramic base cracks or fails.

Both are easy to replace with some care and are inexpensive on ebay- I found a listing for an HVAC tech who was retiring and listing his oem stock on ebay to sell out - supposedly.

Together they cost less than $25 and were in oem unopened boxes, nothing would make me happier than to never have to use them. I struggled with the decision to stock them and the prospect of a couple of 0 degree days pushed me over the edge.

 

It would have to be my guess though. I'd like to build some sort of pneumatic low-pass filter in front of the pressure switch for my on-Prius air compressor (instead of using a switch with more hysteresis—I picked one set for around 60 psi, normal for the spare tire, and didn't want a lot of hysteresis around that value in use).