Let me state up front that I like our furnace tech Richard a lot, and also I am a bad person and should have replaced the filter already and had an HVAC inspection more recently. With that out of the way -

I did have a new filter on hand. I thought “I’ll just sneak this in before Richard gets here in 20 minutes for this long overdue inspection and he’ll be impressed that I recently swapped the filter.” The same way you floss your teeth frantically right before you go to the dentist.

(By the way, I am informed by the dental hygienist that they can totally tell when you only flossed right before coming in.)

So anyway.

TIL: You know how your furnace filter has its dimensions printed on it, in big letters, like “16x25x5” so that you can easily find the right size replacement at your local hardware store? Isn’t it nice that they standardize like this?

IT’S A LIE. BIG FURNACE IS LYING TO YOU.

My old filter CLEARLY says 16x25x5 but the new 16x25x5 filter I bought does not fit in the slot. Somehow it’s just slightly too big.

Richard the furnace tech tells me “You have to look at the fine print to see the actual dimensions”, which in my case is 15-3/4" x 24-3/4" x 4-3/8"

Oh, come ON.

Also.

Rich had to power cycle everything briefly, and now the fancy touch screen thermostat that came with the furnace (six or so years ago) seems to have failed, and boots up to a solid white screen. (Fortunately, the companion app still works so I can still futz with the temperature.)

Hey, things break, it happens. So … Rich, I never really liked that thermostat anyway, its UI is awful, can I just replace it with a Nest or Ecobee or something?

Well guess what: no. Apparently our furnace has some sort of symbiotic relationship with its bespoke thermostat and they communicate via telepathic encoded waveforms that cannot be reproduced by any other thermostat if you want it to work properly, so you need a new one from the manufacturer, and fortunately

• This one is failing for lots of Rich’s other customers
• Rich can get the new model, which is, quote: “better”
• It’ll be here by friday
• The new one has a 10 year warranty, the old one (that you got six years ago) has, of course, a five year warranty
• It’s only $1200.

yikes.

so my furnace

a) cannot use normally sized filters, and
b) won’t work properly with other thermostats, and
c) remind me why I bought this one?
d) maybe the European Union regulators could do something once they’re done with USB-C.

postscript: so what is it we have?

We have a Lennox furnace and Lennox “iComfort” thermostat, which communicate via some proprietary protocol that a Nest or Ecobee - at 1/4 of the iComfort price - can’t handle. Apparently it involves a variable speed blower or variable speed compressor.

I already hated the UI of the iComfort thermostat. It won’t work with HomeKit unless you hack up something with Homebridge (which of course I’ve already done.) But I guess I’m stuck with it now.