So the question becomes how did the tech know the refrigerant level was low before connecting? Was the compressor not coming on? Was the temp drop across the intake/outlet not to target? He must have known for some reason it was low.I asked because some people I know who have had service contracts have discontinued them because they felt the process of removing/replacing the gages results in loss of refrigerant. There seems to be some debate over the extent to which that's a practical problem based on length of hoses and other factors. I've only had the first-year-free contracts and the with the most recent visit the tech checked the refrigerant with gages, but that was because it was already known that the refrigerant was low.Residential , automotive, marine, RV.Do you mean for both residential and automotive or ...?Typically they measure the input and ouput air temps - no need to attach gages if they are fine.
If the output air is a deep enough drop why would anyone pursue attaching pressure hoses?
Something that has definitely changed from my previous first-year-free maintenance visits I've had is that techs no longer remove the housing covers to clean the condenser. I asked and the reason cited - which doesn't surprise me - is that removing and replacing the screws results in more problems from broken/loose screws than the better access improves cleaning. With all the corrosion and vibration that seems reasonable to me. Of course that might be another application for a (very low range) torque wrench (and maybe thread locker.)
I've never experienced any routine maintenance that included intake/outlet temperature so that surprises me, although it seems like a reasonable idea, and of course would be expected if there was a problem reported.
We have worked mostly on marine units and a few automotive units - we did have gages for a while but they are with my son in law now. When a full charge is less than pound and the system yields the target air temp drop I see no reason to attach anything. In these cases where there are problems but the compressor starts and runs and air temp drop is good it was typically air flow. Air flow which can cause low performance , freeze ups, and icing in many cases. From my limited experience anything like connecting the gages also results in larger bill - so one would want a reasonable cause for any next steps.
I have never seen a torque wrench with any HVAC folks - many of these connections are made up with knurled knobs and/or completed with flare nut wrenches using mostly a gentle touch.
Statistics: Posted by smitcat — Wed Jul 31, 2024 1:22 pm — Replies 78 — Views 4865