I read your remark today on York Central Tech Talk re: your York Heat Pump’s perpetual defrosting, and recalled you submitted a post on the HVAC blog some three years ago re: this matter! Has that situation ever been resolved (it doesn’t sound like it). I ask because I have a brand new unit and it is doing the same thing exactly as you described. Driving me crazy! And at this point, a solution doesn’t seem to be readily forthcoming. I would really appreciate hearing about your experience with this matter.
1) I failed to get an explanation from York – nobody who might have engineering knowledge would talk to me. After a couple years of making myself a nuisance to the local York Distributor tech guy, I got the curt advice back from the “York regional tech rep” : ” change the defrost curve jumper from position 3 to 2″ along with no explanation . With nothing to lose, I tried that and it mostly cured the “perpetual defrost” problem, and the only unwanted side effect is that it now waits a little too long before defrosting … but a big improvement overall.
2) A related issue is the fact that the “hot heat pump” feature has never worked as described. Blower speedup only happens when ambient is above roughly 50F. I had hoped that changing the defrost jumper from 3 to 2 might affect “hot heat pump” performance , since both the defrost and “hot heat pump” algorithms supposedly depend on the Liquid Line temperature…. but no – the “hot heat pump” feature is mostly marketing hot air .
3) Related to all this is the defrost control board. Its software has been updated a few times, presumably to correct some bugs – but it seems to be secretly released without much testing.
For example, the defrost cycle used to turn on all auxiliary electric heat to reduce the cold drafts inherent with the defrost cycle reversal method. Later versions decided to stage the auxiliary heaters so that the full auxiliary heat is not turned on until after 15 minutes. This is not much use since the maximum time allowed for a defrost cycle is only 8 minutes. York’s response to my carping was: shrug, silence.
There’s a lot more to complain about, but it really reduces to customer service and engineering ethics – apparently in short supply at York (and probably most of the HVAC industry).
I could go on, but the short advice that I would offer in response to your question is:
1) change defrost jumper from 3 to 2 … I’m assuming that your unit’s documentation says defrost curve 3.
If your recommended defrost curve is something else, you’ll want the defrost curve that brings on defrost at a lower liquid line temperature … York should be able to tell you – but if they can’t / won’t I do have data for several other defrost curves.
2) if , like me, your “hot heat pump” feature doesn’t work (i.e. no blower speedup after 11 minutes) then move the hot heat pump jumper to OFF. Since you now have a one speed system, you may want to change the blower speed jumpers in the indoor unit to achieve the airflow that you like (of course you need the decoder table to know how to set the jumpers – it’s usually in the air handler install manual – I can offer mine if you’re stuck) .
3) If you find the air from the registers too cold during defrost, interchange the W1 and W2 connections, either at the outdoor defrost control board, or at the air handler control board. In my case, W1 alone brings on 5kw, W2 alone brings on 10kw but this may not be quite the same for your system; I have 20kw of auxiliary heaters available, you may have a different configuration depending on your climate.
Unfortunately there aren’t many folks who know anything that are willing to help. Really the only one I found was Mike on the YorkCentral blog – but I sensed that even he was unable to talk to the York engineers responsible for the design of this stuff.
I really think that changing the defrost jumpers was just a “work-around” … and I suspect that the heat pump system is actually malfunctioning – but fat chance in getting any decent diagnosis. Sigh.
Anyway, good luck; I’d be interested to hear how you fare.
Dan S.
p.s. yes. ” Hello World ” does reveal a certain slothfulness – one day I must do better 🙂
I really appreciate your reply. It sounds like I am starting to travel the same road you have been on.
My unit is smaller (2.5 tons), so unfortunately I am already on Pin Setting #1. I do see how moving the jumper from 3 to 2 as your were advised to do would solve some of the problem. As I understand it after much research, the higher pin number equates to more frequent and potentially longer defrost cycles as the units get larger and/or conditions are more severe. I agree with your conclusion – that is not a solution, just a way around a problem.
The tech changed the coil temperature sensor on his first (and only) visit to date. I was confident that would do nothing as my defrost cycles normally terminate in 2-3 minutes suggesting the coil sensor is working. The ambient temperature sensor is working as well as I have artificially raised the ambient temp to over 50 degrees and sure enough no defrost cycle.
I learned from the first service call that the tech really didn’t have a solution, at least at that point in time. I actually spent a hour with a different York dealer while on Christmas vacation at my in-laws. Great talk, but I learned he really didn’t have an answer either.
As I can tell you know, there is no doubt a problem. My previous unit had the time clock and was set to defrost every 90 minutes and operated that way for years – no problems. This new demand defrost system is supposed to be more, not less efficient!
Anyway, I just emailed Luxaire (that’s the brand of my unit, but as you probably know it is essentially the same Johnson Controls product – YorkGuard VI board and all). Will be interesting to hear what I hear back.
I would like to followup with you on this – as they say, misery loves company. My email is freemand@marietta.edu.
dsomerv 
I read your remark today on York Central Tech Talk re: your York Heat Pump’s perpetual defrosting, and recalled you submitted a post on the HVAC blog some three years ago re: this matter! Has that situation ever been resolved (it doesn’t sound like it). I ask because I have a brand new unit and it is doing the same thing exactly as you described. Driving me crazy! And at this point, a solution doesn’t seem to be readily forthcoming. I would really appreciate hearing about your experience with this matter.
Hi Dave:
1) I failed to get an explanation from York – nobody who might have engineering knowledge would talk to me. After a couple years of making myself a nuisance to the local York Distributor tech guy, I got the curt advice back from the “York regional tech rep” : ” change the defrost curve jumper from position 3 to 2″ along with no explanation . With nothing to lose, I tried that and it mostly cured the “perpetual defrost” problem, and the only unwanted side effect is that it now waits a little too long before defrosting … but a big improvement overall.
2) A related issue is the fact that the “hot heat pump” feature has never worked as described. Blower speedup only happens when ambient is above roughly 50F. I had hoped that changing the defrost jumper from 3 to 2 might affect “hot heat pump” performance , since both the defrost and “hot heat pump” algorithms supposedly depend on the Liquid Line temperature…. but no – the “hot heat pump” feature is mostly marketing hot air .
3) Related to all this is the defrost control board. Its software has been updated a few times, presumably to correct some bugs – but it seems to be secretly released without much testing.
For example, the defrost cycle used to turn on all auxiliary electric heat to reduce the cold drafts inherent with the defrost cycle reversal method. Later versions decided to stage the auxiliary heaters so that the full auxiliary heat is not turned on until after 15 minutes. This is not much use since the maximum time allowed for a defrost cycle is only 8 minutes. York’s response to my carping was: shrug, silence.
There’s a lot more to complain about, but it really reduces to customer service and engineering ethics – apparently in short supply at York (and probably most of the HVAC industry).
I could go on, but the short advice that I would offer in response to your question is:
1) change defrost jumper from 3 to 2 … I’m assuming that your unit’s documentation says defrost curve 3.
If your recommended defrost curve is something else, you’ll want the defrost curve that brings on defrost at a lower liquid line temperature … York should be able to tell you – but if they can’t / won’t I do have data for several other defrost curves.
2) if , like me, your “hot heat pump” feature doesn’t work (i.e. no blower speedup after 11 minutes) then move the hot heat pump jumper to OFF. Since you now have a one speed system, you may want to change the blower speed jumpers in the indoor unit to achieve the airflow that you like (of course you need the decoder table to know how to set the jumpers – it’s usually in the air handler install manual – I can offer mine if you’re stuck) .
3) If you find the air from the registers too cold during defrost, interchange the W1 and W2 connections, either at the outdoor defrost control board, or at the air handler control board. In my case, W1 alone brings on 5kw, W2 alone brings on 10kw but this may not be quite the same for your system; I have 20kw of auxiliary heaters available, you may have a different configuration depending on your climate.
Unfortunately there aren’t many folks who know anything that are willing to help. Really the only one I found was Mike on the YorkCentral blog – but I sensed that even he was unable to talk to the York engineers responsible for the design of this stuff.
I really think that changing the defrost jumpers was just a “work-around” … and I suspect that the heat pump system is actually malfunctioning – but fat chance in getting any decent diagnosis. Sigh.
Anyway, good luck; I’d be interested to hear how you fare.
Dan S.
p.s. yes. ” Hello World ” does reveal a certain slothfulness – one day I must do better 🙂
Hi Dan,
I really appreciate your reply. It sounds like I am starting to travel the same road you have been on.
My unit is smaller (2.5 tons), so unfortunately I am already on Pin Setting #1. I do see how moving the jumper from 3 to 2 as your were advised to do would solve some of the problem. As I understand it after much research, the higher pin number equates to more frequent and potentially longer defrost cycles as the units get larger and/or conditions are more severe. I agree with your conclusion – that is not a solution, just a way around a problem.
The tech changed the coil temperature sensor on his first (and only) visit to date. I was confident that would do nothing as my defrost cycles normally terminate in 2-3 minutes suggesting the coil sensor is working. The ambient temperature sensor is working as well as I have artificially raised the ambient temp to over 50 degrees and sure enough no defrost cycle.
I learned from the first service call that the tech really didn’t have a solution, at least at that point in time. I actually spent a hour with a different York dealer while on Christmas vacation at my in-laws. Great talk, but I learned he really didn’t have an answer either.
As I can tell you know, there is no doubt a problem. My previous unit had the time clock and was set to defrost every 90 minutes and operated that way for years – no problems. This new demand defrost system is supposed to be more, not less efficient!
Anyway, I just emailed Luxaire (that’s the brand of my unit, but as you probably know it is essentially the same Johnson Controls product – YorkGuard VI board and all). Will be interesting to hear what I hear back.
I would like to followup with you on this – as they say, misery loves company. My email is freemand@marietta.edu.
Dave