Regular Guest
This is one of those buddy deals over the phone so i dont have any info besides this..it's been in the mid 30's & raining and his 2 stage heat pump is froze so big at the top that the fan blades are hitting the ice. The rest of the condenser has no ice at all. He called the nearest AS dealer & they said dont worry about it that all of them are doing it bc of the weather. I havent looked into it & have very little experience with AS, just wanted to hear some thoughts.
Regular Guest
This is one of those buddy deals over the phone so i dont have any info besides this..it's been in the mid 30's & raining and his 2 stage heat pump is froze so big at the top that the fan blades are hitting the ice. The rest of the condenser has no ice at all. He called the nearest AS dealer & they said dont worry about it that all of them are doing it bc of the weather. I havent looked into it & have very little experience with AS, just wanted to hear some thoughts.
Professional Member*
Is water falling from the roof/gutter right on the top of the unit?
Always here
Professional Member*
.
Heat pumps and freezing rain is not a good thing. Have them switch over to their aux heat
until temps warm up and the sno cone thaws.
..
Do not attempt vast projects with
half vast experience and ideas.
...
Regular Guest
Was looking for a technical explanation. I already know that heat pumps suck and they have supp heat. But it shouldnt freeze enough to hit the fan blades if it was working properly.
Regular Guest
No but it has been steadily raining for 5 days. But that still doesn't explain the top few rows being all that freezes does it?
Professional Member*
Well... maybe
Think with me: The fan sucks air over the coils... and blows this cold air out the top. In many cases, the temp of that air is below freezing. So where do you think the ice will form first?
May be different on different machines...
This is why I prefer a Demand rather than a Timer defrost board. They tend to catch this sooner... yet not defrost until it is needed.
GA-HVAC-Tech
Your comfort, Your way, Everyday!
GA's basic rules of home heating and AC upgrades:
*Installation is more important than the brand of equipment
*The duct system keeps the house comfortable; the equipment only heats and cools (and dehumidifies)
*The value of comfort, over the long term; leave economic choices behind!
Choose your contractor wisely!
Regular Guest
Ok, I'm going to think out loud so correct me when I'm wrong. "Freon enters the bottom of the condensing unit (evaporator in heat mode and coldest point of the cycle), absorbs latent heat until it becomes 100% vapor and continues out the top constantly gaining superheat (which would be its warmest point)." That's my thinking so now why would it only freeze at the warmest part of the process?
Global Moderator
Trane is demand. Mid 30s and pouring rain could cause weird things. Usually sensors are mounted low so could be that icing was so bad that the sensor detected a warm coil low down and stopped the defrost. I'd go on em heat and see what happens under normal conditions.
Regular Guest
They have 2 identical units put in at the same time. The other is on a different house a couple hundred yards away and it freezing evenly like normal.
Professional Member*
They need a good tech, that is not normal under any weather. Trane/Am Std with demand defrost almost never have defrost issues.
I would start by thawing it out completely and then running it and observing the frost pattern.
Regular Guest
I am going to go check it for them when the rain stops. I'm new to this site so I posted it here to see if there was really any "techs" or "professionals" on this board. So far i've mostly seen parts swappers. Smh
Professional Member*
Heat Pumps don't "suck", it might be under charged if only half the coil is freezing up. If it has a defrost sensor it might be located at the other end of the coil and not reach the specified temp to kick it into defrost.
It doesn't have to be a "AS" tech, it needs to be a competent tech.
~smoke~
"That motor's done, he let the factory smoke charge out!"
Professional Member*
On another note, what company is turning away a service call? At least send some out to check out the system and gain a customer.
~smoke~
"That motor's done, he let the factory smoke charge out!"
Regular Guest
They turn lots away if it is more than a 15 minute fix or if they cant sell them a new unit. I know why its not defrosting, The question is why is the top freezing and the bottom not?
Professional Member*
Good to hear Trane is Demand... we do not have many HP's around my area.
Usually the outdoor coil is split into 4-5-6 parallel sections... big manifolds on the side. Should be similar temps all up and down.
Let us know what you find! THX
GA-HVAC-Tech
Your comfort, Your way, Everyday!
GA's basic rules of home heating and AC upgrades:
*Installation is more important than the brand of equipment
*The duct system keeps the house comfortable; the equipment only heats and cools (and dehumidifies)
*The value of comfort, over the long term; leave economic choices behind!
Choose your contractor wisely!
Professional Member
my guess is that the house has no gutters and the melting ice is dripping right on the center of the heat pump.
Professional Member*
The rain freezes on the top and not the coils. It has no way of defrosting the ice and it just collects until it interferes with fan blade.
Professional Member*
hope he already turned it to emergency heat
Professional Member*
This issue could be caused by several things. Trane/AS use demand defrost. It has two sensors. A condenser coil sensor and an ambient temp sensor. It is constantly sensing the delta t between these two sensors. Once the calculated delta t is met, a defrost cycle is intiated.
Check the sensors. The coil sensor is located on the bottom of the coil, move it to the top and see if that remedies the issue. All sensors can be ohmed. Check the service manual for temp - resistance chart.
This is an open forum. We try not to get too technical here. Get your post count up and apply for a pro membership, then you can see what this site really has to offer.
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