New system,AC ok~~~Heater is making noise!

[SamNglenallen]

Greetings...

have searched/reviewed archives...(don't you just love the descriptive subj lines some folks don't use!...LOL)

But was unable to find any probs/questions that seem to relate to my problem!

We have a newly installed system (late spring/early summer 04)...we had our problems with the "friendly neighborhood guy, working on the side"...but eventually all seemed well!

We put in the upgraded unit~~~Cooling was great...operating cost actually went down, as it was more efficient!...1st time comfortable in 4 years living in this 20 yo house.

THEN CAME COLD WEATHER...Initially we had similar positive effects...with a 3x increase in KW heater...it is SWEET!!!!

But, here is the delima~~~several weeks ago we started hearing a low rumble that increased in volume/vibration and then peaked and faded away!...kinda like a train or tremor passing.

It is coming from the outdoor unit as it cycles on or off(?).

We have had a wierd fall/winter here in central Virginia...it never got real cold...then got real warm...and it is now REAL COLD!!!!

We actually switched it back to AC for a couple of days when it was 70+ degrees and very humid!...upon switching it back to HEAT the sound seemed to have vanished (but it was still not real cold)...

WELL now that we have more characteristic frigid cold (15-30 degrees)...The vibration/noise is back!!! and sems to be originating from the outside unit but definately is transmited somehow to the house frame/ducts!

HELP PLEASE???

What is this, and what is the appropriate course of action?

Is it the machine or do I need a GHOSTBUSTER?

THANK YOU in advance for any possible help/advice/guidance!

SamNglenallen

[mattison]

Does it do it continuously or a couple times an hour?

It could be going into defrost and making this noise. When it's doing this go outside and see if anything is strange. In heating mode the fat copper line should be hot and the skinny copper line should be cool, and the fan should be blowing out cold air.

[SamNglenallen]

"...But, here is the delima~~~several weeks ago we started hearing a low rumble that increased in volume/vibration and then peaked and faded away!...kinda like a train or tremor passing.

It is coming from the outdoor unit as it cycles on or off(?)..."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I forgot to say it is only 5-30 seconds in duration...if you ever experience a mild earthquake...it is kinda like that???

it seems to be only when the outside unit kicks on...I have tried to be out there when it happens but no luck!!!

NO it is not continuous or severl times an hour...

All other aspects of the system seem to be working fine!

Thanks,
Sam

[SamNglenallen]

everything is running right now:

Hot air from ducts;
cold air from outside unit;
small pipe seems room temp (cool not cold);
large pipe warm (warm not hot).

I felt the copper pipe at both units inside and out...

Did notice a very mild vibration inside tween wall and unit.

?????????

Thanks,
Sam

[Ed Imeduc]

You say in the outside unit. go out there by it and have some one then turn the unit to heat and push the tstat up.Would you say its in the fan the 4 way valve the compressor. Can also do this inside could be the check bypass valve on the coil. Its things like this that you just have to like feel out.

ED ;)

[mattison]

Another thing I would check is if it has a crank case heater for the compressor. If it don't, during the off cycle the refrigerant outside is all liquid and when it starts it's slugging away. A crank case heater keeps the oil heated up in the compressor and helping to avoid the violent starts.

[SamNglenallen]

well...it is the coldest dayof the season here...

Everytime I have checked it has been running~~~haven't experienced a single rumble all day...

...ooops till just a few moments ago!!!

I got busy and forgot to check for the past couple of hours!

and of course that was the only time the sun was shining on the back of the house...must have warmed up enough to cycle off...and just restareted...along with the rumble/vibration!!!

DANG!!!

TSTAT set at @68/69....Thermometer reading 72...we have been comfy (one or the other (or both) is out of adjustment).

This is driving me nuts!

Sam

[Ed Imeduc]

IS the tstat level on the wall????? that will make them off

ED ;)

[SamNglenallen]

YES...on the wall.

~~~~~~~~~~~~~~~~~~~~~~~
OK...was just outside loading up on firewood before the snow comes this p.m. ... Checked out the outside unit...

FAN had stopped...but
Sounded like the compressor was still running...
certain spots around the grill cover seemed like warm air rising...

I pulled the breaker on the wall, waited a while and plugged it back in..............

Fan started up...seemed normal then the slow steady rumble started and peaked then faded out...
it came from the lower base of the unit~~~like the compressor was having a had time starting up...

????????

Does this make any sense???

Sam

[SamNglenallen]

MATTISON...

I noticed that it is happening tonight approx 1 x hour...lasting maybe 2-3 seconds.

Thanks
Sam

[mattison]

It sounds like it's just going into defroset. The time you pulled the disconnect and plugged it back in would have made it struggle to start.

When it goes into defrost the system reverses it's normal operation and heat is sentthroughthe outdoor unit to melt any ice off of it, and at the same time the back-up heat will come on to compensate.

[scottg]

No really from what you have been writing I think that it is going into defrost and that the noise is comming from your liquid line ie.. the small line that in not insulated.

Here check to see that both refrigerant lines are taped together at least every 5 feet I do it every 4 feet but anyways this takes the vibration out of the liquid line or deadens it. You should also have them straped every 5 feet to a member. ie.. floor joist, ceiling joist, or wall stud.

This should take out the rumble that you hear.
Just another job that was not installed properly.

I hope that you get the problem solved and that you have no more problems with your heatpump.