Hi,
I'm a new homeowner (3 years) and never had a central HVAC before (baseboards only in my old house), so this is kind of new to me. The house was built in 1998 and the heat pump that's installed is a 3T York, still running fine. This fall I had to replace a flow sensor on the outside unit because the HP would shut down after 2 minutes when heat was demanded. The cooling worked fine the whole summer. The sensor obviously wasn't original and seem to have been replaced in the past already. Since its replacement, the HP is running fine again.
I'm living in southern Quebec, so winters can get very cold (down to -30°C). Currently it's around 0° to -5°C and the HP runs all the time, and I noticed that versus last year at this time of the season, the HP coil outside would start freezing in the upper loops, but not at the bottom, which makes me believe there is some pipes clogged?
See the attached picture.
I don't recall having seen this behavior in the past, not that early in the season. Also, what temperature should I measure coming out from the air registers in the house? When the heat is calling, I get average 25-27°C measured with a laser thermometer. I never took that temperature when we moved into the house 3 years ago, so I don't know what it used to be.
The whole unit is controlled by a Honeywell RTH6580WF T-stats that I bought about 2 years ago to replace the original Emerson 'electronic' stats. I wanted to be able to remote control the temperature with a mobile app, but the Honeywell Total Connect proved to be a very unreliable API service... I bought a Sensi (Emerson) ST55 Wi-Fi T-stats to replace it this spring, and it worked fine thru the summer, but now that heat is required, I noticed that it had the bad behavior of calling for Emergency heat (AUX) even when it was way above 10-15°C, which to me makes no sense, but I couldn't get an answer from Emerson why that is. So I switched it back to the Honeywell T-stats.
I had an HVAC tech check the whole unit and indoor furnace this spring and everything was looking good from the pressure side (still using R22), though it is an old installation. I cleaned up the indoor coil completely recently and change air-filter on a regular basis. This tech was actually called in this spring because the HP would turn off quite often and not come on as expected after a moment. The control board outside would blink with a code (6x) which indicated a sensor failure, but the tech would diagnose a dirty filter only and had them changed and restart the HP.. Since it was end of June, heat wouldn't be demanded as much anymore and the HP ran just fine the entire summer in A/C mode.. I only realized the sensor issue again this fall, and ordered one on-line to replace the faulty one.
Hope someone can shed some light and how I can get this sorted out.. If I can avoid the replacement of the entire system that would save me about x$, as that's what I was quoted by a few contractors (inside & outside units). Since it's an old system, the inside furnace heat elements need to be replaced too.
One last thing: originally the HP control board was set to allow to run the HP down to 0°F (-18°C) from factory settings, but that's way too cold for our region, as the whole HP would be completely covered by frost & ice in the midst of winter some days when there was a snow storm. So I changed the jumper to +10°F (-12°C) which is more adequate I believe for such an equipment.
I'm a new homeowner (3 years) and never had a central HVAC before (baseboards only in my old house), so this is kind of new to me. The house was built in 1998 and the heat pump that's installed is a 3T York, still running fine. This fall I had to replace a flow sensor on the outside unit because the HP would shut down after 2 minutes when heat was demanded. The cooling worked fine the whole summer. The sensor obviously wasn't original and seem to have been replaced in the past already. Since its replacement, the HP is running fine again.
I'm living in southern Quebec, so winters can get very cold (down to -30°C). Currently it's around 0° to -5°C and the HP runs all the time, and I noticed that versus last year at this time of the season, the HP coil outside would start freezing in the upper loops, but not at the bottom, which makes me believe there is some pipes clogged?
See the attached picture.
I don't recall having seen this behavior in the past, not that early in the season. Also, what temperature should I measure coming out from the air registers in the house? When the heat is calling, I get average 25-27°C measured with a laser thermometer. I never took that temperature when we moved into the house 3 years ago, so I don't know what it used to be.
The whole unit is controlled by a Honeywell RTH6580WF T-stats that I bought about 2 years ago to replace the original Emerson 'electronic' stats. I wanted to be able to remote control the temperature with a mobile app, but the Honeywell Total Connect proved to be a very unreliable API service... I bought a Sensi (Emerson) ST55 Wi-Fi T-stats to replace it this spring, and it worked fine thru the summer, but now that heat is required, I noticed that it had the bad behavior of calling for Emergency heat (AUX) even when it was way above 10-15°C, which to me makes no sense, but I couldn't get an answer from Emerson why that is. So I switched it back to the Honeywell T-stats.
I had an HVAC tech check the whole unit and indoor furnace this spring and everything was looking good from the pressure side (still using R22), though it is an old installation. I cleaned up the indoor coil completely recently and change air-filter on a regular basis. This tech was actually called in this spring because the HP would turn off quite often and not come on as expected after a moment. The control board outside would blink with a code (6x) which indicated a sensor failure, but the tech would diagnose a dirty filter only and had them changed and restart the HP.. Since it was end of June, heat wouldn't be demanded as much anymore and the HP ran just fine the entire summer in A/C mode.. I only realized the sensor issue again this fall, and ordered one on-line to replace the faulty one.
Hope someone can shed some light and how I can get this sorted out.. If I can avoid the replacement of the entire system that would save me about x$, as that's what I was quoted by a few contractors (inside & outside units). Since it's an old system, the inside furnace heat elements need to be replaced too.
One last thing: originally the HP control board was set to allow to run the HP down to 0°F (-18°C) from factory settings, but that's way too cold for our region, as the whole HP would be completely covered by frost & ice in the midst of winter some days when there was a snow storm. So I changed the jumper to +10°F (-12°C) which is more adequate I believe for such an equipment.
source https://hvac-talk.com/vbb/showthread.php?2224002-My-20-y-o-York-HP-started-freezing-on-upper-coil-part-but-not-bottom-How-Fix&goto=newpost
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