not sure what's wrong

Posted by KJPRO on May 15, 2008, 1:36 pm

> Very possible you have a load of air in the system.

Parrot

> I'm learning to make good use of my IR thermometer. A hot filter dryer
> (after the condensor) means that the condensor needs cleaning.

Not always...

> The guys on
> the list groan, roll their eyes, and call me a hack.

Just stating FACTS!

> But I've learned that
> even a clean looking condensor can be way below efficiency.

Many OTHER problems can cause this...

> Christopher A. Young
> Learn more about HVAC
> Other than that, I'm just a HACK

Posted by Gary on May 14, 2008, 1:18 pm

My first assumption would be that your low on gas.
Your running over 40 degrees SH & your subcooling is not bad but I
would suspect a little low for that system so nothing to me sounds like an
overcharge. I would add a little gas & see if it brings your SH in line &
raises your TD. If that doesn't work then I would follow Noon-Air's advice
but I always try the easiest way first. If it is low on gas then I would
check the indoor coil because I've had countless of those Heil coil leaks.

Posted by KJPRO on May 14, 2008, 3:22 pm

> Most of my work has been new construction and very little service tech
> so forgive me if this is too simple. My ex-wife called me a few days
> ago and said her heat pump wasn't cooling.

This is your problem HOW????
She's an EX for a reason!

> She said someone replaced
> the compressor, which made it much better, but it's still not cooling
> like it should. So I thought that unless I want to give her even more
> of my hard earned money, I better load up the truck and head over.

More of your money??? Are you required to maintain HER equipment or living
conditions???

> Here's what I found. It's a 3 ton 10 seer HEIL split system heat pump
> with a TXV. New copeland recip compressor and new dual cap. Coils
> are clean, filter is clean. I put the guages on and that's when I got
> a little confused.
> outside air temp - 81
> inside air temp = 78
> Outdoor humidity: ~70%
> Suc Pressure - 64
> Suc temp - 80
> Liq Pressure - 200
> Liq temp - 87
> Condenser TD - 13
> Evaporator TD - 14
> My handy Trane charging chart shows it being slightly overcharged....
> but shouldn't be enough to give me such a low TD across the evap.
> Rather than just start fiddling with the charge I thought I might want
> to actually try to figure out what's wrong with it.
> The only other thing out of the ordinary is the condenser fan was
> replaced with one that's 75 rpm faster. It calls for a 1075 rpm and
> has a 1150. In my brief experience I believe that won't have a big
> effect.
> any ideas?

How long is the lineset and where is its location?
Have you checked for proper indoor fan speed?
The system is NOT overcharged or you would have a higher Subcooling reading.

Posted by Zyp on May 15, 2008, 11:31 am

richard_ln@yahoo.com wrote:

> Most of my work has been new construction and very little service tech
> so forgive me if this is too simple. My ex-wife called me a few days
> ago and said her heat pump wasn't cooling. She said someone replaced
> the compressor, which made it much better, but it's still not cooling
> like it should. So I thought that unless I want to give her even more
> of my hard earned money, I better load up the truck and head over.
> Here's what I found. It's a 3 ton 10 seer HEIL split system heat pump
> with a TXV. New copeland recip compressor and new dual cap. Coils
> are clean, filter is clean. I put the guages on and that's when I got
> a little confused.
> outside air temp - 81
> inside air temp = 78
> Outdoor humidity: ~70%
> Suc Pressure - 64
> Suc temp - 80
> Liq Pressure - 200
> Liq temp - 87
> Condenser TD - 13
> Evaporator TD - 14
> My handy Trane charging chart shows it being slightly overcharged....
> but shouldn't be enough to give me such a low TD across the evap.
> Rather than just start fiddling with the charge I thought I might want
> to actually try to figure out what's wrong with it.
> The only other thing out of the ordinary is the condenser fan was
> replaced with one that's 75 rpm faster. It calls for a 1075 rpm and
> has a 1150. In my brief experience I believe that won't have a big
> effect.
> any ideas?

I'm thinking your TXV isn't opening enough to fill the coil completely with
refrigerant, hence a low TD across the evaporator with a high superheat....
[low performance.]

All other signs seem normal, except that since the evaporator isn't getting
enough refrigerant, I'd see a low head pressure because the system isn't
picking up enough heat......

Thinking about Noon-air's recommendation, I'd likely go his route but
install a new TXV while I'm there cleaning / checking the screen before the
valve.

--
Zyp

Posted by on May 15, 2008, 11:49 am

>richard_ln@yahoo.com wrote:

>> Most of my work has been new construction and very little service tech
>> so forgive me if this is too simple. My ex-wife called me a few days
>> ago and said her heat pump wasn't cooling. She said someone replaced
>> the compressor, which made it much better, but it's still not cooling
>> like it should. So I thought that unless I want to give her even more
>> of my hard earned money, I better load up the truck and head over.
>> Here's what I found. It's a 3 ton 10 seer HEIL split system heat pump
>> with a TXV. New copeland recip compressor and new dual cap. Coils
>> are clean, filter is clean. I put the guages on and that's when I got
>> a little confused.
>> outside air temp - 81
>> inside air temp = 78
>> Outdoor humidity: ~70%
>> Suc Pressure - 64
>> Suc temp - 80
>> Liq Pressure - 200
>> Liq temp - 87
>> Condenser TD - 13
>> Evaporator TD - 14
>> My handy Trane charging chart shows it being slightly overcharged....
>> but shouldn't be enough to give me such a low TD across the evap.
>> Rather than just start fiddling with the charge I thought I might want
>> to actually try to figure out what's wrong with it.
>> The only other thing out of the ordinary is the condenser fan was
>> replaced with one that's 75 rpm faster. It calls for a 1075 rpm and
>> has a 1150. In my brief experience I believe that won't have a big
>> effect.
>> any ideas?

>I'm thinking your TXV isn't opening enough to fill the coil completely with
>refrigerant, hence a low TD across the evaporator with a high superheat....
>[low performance.]
>All other signs seem normal, except that since the evaporator isn't getting
>enough refrigerant, I'd see a low head pressure because the system isn't
>picking up enough heat......
>Thinking about Noon-air's recommendation, I'd likely go his route but
>install a new TXV while I'm there cleaning / checking the screen before the
>valve.

Check that the bulb is properly mounted and insulated.

--
Click here every day to feed an animal that needs you today !!!
www.theanimalrescuesite.com/

Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo online at www.pmilligan.net/palm/
Free 'People finder' program now at www.pmilligan.net/finder.htm

Page 2 of 9 < 1 2 3 > last >>

Similar Threads	Posted
I'm in the wrong business	January 5, 2007, 7:44 am
i need help understanding what is wrong with my refrigerator	July 4, 2009, 10:46 am
Remote thermometer in wrong place?	January 15, 2008, 2:03 am
DIY Water Heater repair. When simple things go wrong	January 25, 2007, 10:52 am

not sure what's wrong - Page 2