noisey heatpump

[wadesquad]

i am a service tech and i am having some troubles narrowing down why this compressor is so noisey on start up and in defrost.. it is also under heating and uderamping

luxaire hp ho5bo36f1

this is a two stage 3ton heat pump and it is mated with a matched cased coil and txv

410a
dist psi: 245
dist temp:101
suct psi: 75
suct temp: 23
liq psi: 230
liq temp:78
amps: 8.5
oat: 32
rat: 60
dat:80

ive installed several of these heat pumps and all except this one are very quiet.

[beenthere]

Improper charge or restriction in refrigerant circuit.

[BaldLoonie]

How long is the lineset? With huge coils and need for lots of juice, these things can be noisy on start up. Also many brands are stopping their compressor in & out of defrost to quiet them.

[wadesquad]

thanx for the responses so quickly

lineset: 20ft to evap in basement
ref chage: 9 1/2lbs


heres a lil history... its been loud since day one. i replaced the comprssor, indoor txv, outdoor txv, bidirctonal filter drier, and raised it up on blocks (per factory rep)... this unit is only a lil over a yr old too!...

is it possible and how would i be able to find out if the J tube in the accumulator was clogged and the compressor was starving for oil?

[CynicX]

It must be crazy loud to go through all of that.

Is the amp draw, pressures, and everything normal?

Do have have experience with Luxaire? Have you installed other system that were quieter? I've never know them to be the quietest HP on the market if you know what I'm saying....

[beenthere]

It must be crazy loud to go through all of that.

Is the amp draw, pressures, and everything normal?

Do have have experience with Luxaire? Have you installed other system that were quieter? I've never know them to be the quietest HP on the market if you know what I'm saying....

Then you have never installed any of the 2 stage units.

[beenthere]

thanx for the responses so quickly

lineset: 20ft to evap in basement
ref chage: 9 1/2lbs


heres a lil history... its been loud since day one. i replaced the comprssor, indoor txv, outdoor txv, bidirctonal filter drier, and raised it up on blocks (per factory rep)... this unit is only a lil over a yr old too!...

is it possible and how would i be able to find out if the J tube in the accumulator was clogged and the compressor was starving for oil?

If the compressor was starving for oil. It would of seized up by now.
And the accumulator would be just about full of oil from storing the oil of 2 compressors.

Look at you LL pressure and temp. You have no SC.

[wadesquad]

cynicX...yes these 2 stage units are usually crazy quiet... low amp draw and low pressures

ure right 230psi = about 80degrees
LL temp= 78 degrees actual temp
no sub cooling? that does explain why i have bubbles in the sight glass...

fan speed it set for the tonage on the furnace board and it does sound llike the ecm blower is ramped on high too...

[wadesquad]

bump...

[beenthere]

bump...


What have you checked/done recently.


Find out why you have virtually no SC.

[rundawg]

ure right 230psi = about 80degrees
LL temp= 78 degrees actual temp
no sub cooling? that does explain why i have bubbles in the sight glass...

but......something doesn't add up here.......


lineset: 20ft to evap in basement
ref chage: 9 1/2lbs

The manual says, for 15 ft of lineset you need, or have in the unit already, 8lbs 8oz. Then you add .62 oz/foot for over 15ft. That adds up to an additonal 3.1oz, or a total of 8lbs 11oz for 20feet. If you have 9lbs 8oz in the system, my math has you 13oz (almost 1 lb) over charged.

Are you sure you have 9.5 lbs in the system? Did you take into account the equivalent lenght of all the fittings (90's and 45's) between the inside and outside units? Did you assume the unit had 8lbs 8oz in it to start with?

[wadesquad]

two days ago i changed the outdoor txv but i seemed to make no difference..

i cant understand why i would have no sub cooling..? the only way i can comprehend is if the evap sum how the was short curciting hot gas back into the liquid side... but how ever could that happen? and wouldnt my liquid line be warmer than 78 degrees?

rundawg.. i have an 48k evap coil and a 36k txv it wanted 14oz additonal charge to accmodate the larger coil

[beenthere]

Time to get the factory tech rep out with you.

[wadesquad]

there seems to be a huge comunication prob between york/johnson controls and me... !! everything is a week or more behind..

i read this forum alot and there are some very smart pple on here i thought id ask for sum help since the factory seems to be lacking

[beenthere]

Your changing parts.

But, you don't seem to be doing any individual part/component testing.

What would cause you to have little to no SC in cooling mode. What would you check if it was a cooling problem?

[wadesquad]

Your changing parts.

But, you don't seem to be doing any individual part/component testing.

What would cause you to have little to no SC in cooling mode. What would you check if it was a cooling problem?

a slow or dead condenser fan.. or a dirty condenser

[beenthere]

When is the last time you had your scale checked.

Your SC is indicating a charge problem.

[wadesquad]

When is the last time you had your scale checked.

Your SC is indicating a charge problem.


ive never checked it

if i know the fan is up to speed and evap is clean... SC would indicate i should add a few more oz. of charge

however that still doesnt point me to the direction of the dead waking cimpressor noise in defrost and noisy startups

[beenthere]

Lots of heat pumps are loud when they aren't charged right.

[wadesquad]

ok ill add a bit of charge and see if i can get my SC more in line where it should be and ill report my results bak..

thank you to every1 who responded to my thread!

[wadesquad]

ok i know this is a really old thread but i have a an update

factory rep advised me to change the defrost board because they have changed the software to kill the compressor before defrost intiation and before defost termination. the loud defrost is is less noticible but still not ideal.

the other morning i noticed a strange frost pattern on the condenser any ideas?

it seems to me that i am loosing abt 20% of my heating capacity

[beenthere]

Thats normal. You would spent more money using the strip heaters during defrost, then what little efficiency your losing from that frost.

[wadesquad]

thats not during defrost thats during a heat cycle right before defrost. shouldnt my coil be uniformly frosted

[beenthere]

thats not during defrost thats during a heat cycle right before defrost. shouldnt my coil be uniformly frosted

No. Thats a common defrost pattern that is seen. It has an on demand defrost board. It doesn't need defrosted yet, and so its not wasting energy doing a needless defrost, like a time and temp board would do.

[wadesquad]

noisey defrost aside, my concern is why in a heating cycle are some portions of the coil frosted and sum not? haveing a txv and distributor shouldnt the coil be feed with equal amouts of ref?

[Marcus Maynor]

Not able to see attactment for some reason. On the noise issue I had a similar problem with noisy compressor in cooling mode and had found that the reversing valve was allowing hot gas to leak through to suction line. Might try getting a tem dif across suction lines at reversing valve and someone may correct me here but you should get no more then 3 deg F. Id also check temp difference across accumalator

[wadesquad]

Not able to see attactment for some reason. On the noise issue I had a similar problem with noisy compressor in cooling mode and had found that the reversing valve was allowing hot gas to leak through to suction line. Might try getting a tem dif across suction lines at reversing valve and someone may correct me here but you should get no more then 3 deg F. Id also check temp difference across accumalator

thats a few good things to check! thanx for the info

[beenthere]

noisey defrost aside, my concern is why in a heating cycle are some portions of the coil frosted and sum not? haveing a txv and distributor shouldnt the coil be feed with equal amouts of ref?

It not a tuned distributor like you would have with fuel lines in cross over duel injection.

[wormy]

Trane condensing units use the bottom portion of the outdoor coil as a subcool circuit.
That portion of the coil does not frost like the rest of the coil
Wonder if your unit is piped the same way.

Have you checked to see if the accumulator is piped correctly.
Put a temp prob on the suction line at the compressor and
see if you're getting liquid slugging the compressor.

Also check the compressor start and run capacitors.

Make sure everything is wiring in correctly.
I've run across a new unit with the condenser fan motor
wired wrong. It ended up running backwards.
Run and Start wires were mismatched.

Voltage applied to compressor during start up and while running.