Not Too Cool

     In the first few days of the Spring heat wave, the air-conditioner coil in the furnace here at Roseholme Cottage froze up.  (I've been calling it an A-coil, but it's got one more section, so it's really an N-coil.)

     That wasn't too great. I managed to catch it early: air was still flowing but the cold side of the coolant line was frosted up nice and white where it's exposed as it goes into the box where the N-coil lives.  I turned the thermostat up several degrees, left the fan running and added a floor fan over the register in the dining room -- that one's only six feet away from the return dust grill, and the system works better if I can loft the cold air up and displace warm air into the floor-level return.

     Tam had out-of-town stuff to do over the next week and a half after I found it and I had several projects at work, so service had to wait.  I figured the system was just low on coolant, which (for abstruse reasons I have neither the time nor the crayons to share my limited understanding of) can make the N-coil tend to get much colder than it it should and freeze up.  In the meantime, I could probably manage it by not cooling the house any more than the bare minimum needed to control humidity.  You have to pay attention to the outside temperature and if the ducts in the basement are sweating, but if the system's not too messed up, it works.  I fired up booster fans in the bedrooms and it worked through a couple of weeks of bad heat.

     Then we had the flea explosion.  I had scheduled service by then, but Tam had to go out of town again and the house was a mess with bags of to-be-de-flea-ed stuff all over, so I cancelled it -- I thought.

     A few days later, the tech knocked while I was in the shower and we had a short, unhappy conversation.  That was early last week.

     After rescheduling and apologies all around, he showed up yesterday morning and worked his magic.  Yes, the system was low on coolant -- but after topping it up, it was still acting funny.  I'd drawn the newest tech; he spent some time on the phone with his more-experienced peers and came back to tell me that either the high-tech self-regulating expansion valve was shot -- or the coil was.  The latter was going to be costly and even the valve would be painful because it's labor-intensive (or time-intensive, at least: they have to empty the system, but refrigerant's too expensive to waste, so it gets pumped down and saved, and that's not a quick process.)

     He left and I called his office for an official quote.  They reminded me that the bill would be less if the system happened to be under warranty.  I asked them to hold that thought, I'd call right back after checking.  Turns out I had registered it back in 2017, and yes, it was a ten-year warranty if you bothered to register.  I called back, and now the service outfit wanted to send another tech out to make sure the problem was as diagnosed.  (I can't blame them for that.  The parts markup on a coil is a nice chunk of change and some or all of that is now off the table.) 

     Early this morning, the previous tech returned, skeptical senior in tow, and they did another round of measurements.  The original guy was vindicated (and happy about it.  It sucks to be the new kid -- BT, DT), and I'm waiting to hear back on scheduling the replacement.

     Meanwhile, we're in another hot streak and I'm managing the thermostat.