Bad A/C reversing valve?

Page 5 of 5  

Putz
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Maybe when you sober up you'll come back and read your own posts. Pretty silly there drunken, dancing, monkey boi. I post and you dance. *It never fails*.
--
---
there should be a "sig" here
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Have anything intelligent to say?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Maybe when you sober up you'll come back and read your own posts. Pretty silly there drunken, dancing, monkey boi. I post and you dance. *It never fails*.
--
---
there should be a "sig" here
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The four way reversing valve is energised on cooling and de-energised on heating. Set the thermostat UP to 30C and the valve should de-energise and HEAT Set the thermostat DOWN to 15C and the valve should energise and COOL

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The Four Way Reversing Valve is a sealed PILOT operated valve with four ports. The two centre ports are connected to the Accumulator and Discharge and the adjoining ports if the Valve is sealing correctly should have temperatures equal to the temperature of a centre port. As an example on cooling with the Solenoid Valve energised the port connected to the outdoor coil should have a temperature equal to the discharge port on Heating with the solenoid valve de-energised it should have a temperature equal to the accumulator port. Cycling the internal slide valve backwards and forwards by switching from heating to cooling will usually Flush out contamination and seal the valve.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

1) Ask the installing company for a copy of the heat load calculation that was done when the 3 ton unit was sized for the space that is being air conditioned. That's the only way you'll know if it was correctly sized for the application.
2) What is the return-side temperature at the air handler? If it is more than a few degrees over the air temperature measured at the interior return grill(s), you have a duct leak on the return side.
3) Has the supply plenum and duct work been checked for leaks?
4) Any competent contractor can take a eight or so readings (of pressures, temperatures) and determine what the problem is without any guessing.
5) With an 18 degree delta-T I seriously doubt that you have a defective reversing valve. Don't let the contractor hack into your system unless Bryant confirms that this is the cause of your problems.
Good luck - it sounds like you will need it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 31 Aug 2007 14:55:21 -0700, snipped-for-privacy@gmail.com wrote:

If you have an 18 degree temp difference then you have about a one percent chance that there is a problem with the reversing valve. You are getting the run around or some stupid techs or both.
Some things to have them check:
Are the return and supply ducts sized correctly? If they say they are then make them show you there manual D calculations. Is the return grill sized correctly? Are the ducts sealed and free of kinks? Is the return duct connected to a plenum or just hacked into the air handler? Is the line set free of kinks? Are the filters clean? Did the installing company do a load calculation or just take a swag at it? If they say they did a load calculation then make them show it to you. Is the system charged correctly? Is the indoor blower set to the correct speed tap? Is the evaporator coil restricted with loose insulation etc.? Is the condenser restricted or blocked by anything? Is the condenser placed under any structures like a deck etc.?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I understand your posting that is good chance of having bad/leaky reversing valve and I am agreeing with you in addition to that possible bad compressor but neither one of us can say that unless you are there with gauges to check it out. what puzzle me (and I am asking ) if you have any problem with air supply/moving would it be greater temperature difference instead of smaller because coil/evaporator would be working at lower temperatures unless you are taking air from outside instead of recirculating air from inside, hmm that is possibility that fresh air damper is "oversized/stuck open or ?". Tony Note: kjpro I do not need your shit
<oldacdude> wrote in message wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for all the info, I'll gather whatever info I can as I've had different diagnoses, false fixes, and opinions from 5 techs now. All of the return filters and vents I have replaced and seem ok. Here's the latest: -I spoke with the owner of the company that installed and has been servicing the unit. He says one of his techs felt the TXV valve was bad but they worked with Bryant over the phone who said the reversing valve was bad based on the data given. He said it would be close to $1000 to replace both and I should call Bryant and bitch to see what they'd do since the unit is only 14 months old. -I called a new hvac company for a 2nd opininon. They sent a tech out. He measured the refrigerant psi for the lines attached to the condenser. He noted the pressure was climbing from 200 to almost 400 psi, at which point the release valve kicked in and it would soon start all over again. He had eventually gotten the pressure stable and said he believed there was contamination in the line and the issue was now fixed (although I found no change later on). This is the info he gave me on what he did:
-found system overcharged -found system heat pressure raising to 450psi from 210 -pumped system down, inspected piston at liquid line at condenser & screen at condenser. Found a small chunk of possibly brazing rod -flushed nitrogen through lineset to make sure there was good flow -pulled system into deep vacuum -recovered some of refrigerant to proper charge -system working properly -suction & liquid pressure steady - 10 degree superheat LO 80 -12 degree subcooling Hi 200 -18 degree delta T - compressor amps 10.1
I called the company back and they sent out another guy. He energized/ de-energized the reversing valve using heat and cooling but it did not help. He had been looking at the air handler and says there's no filter drier installed and now the system needs to be cleaned out, txv replaced, filter drier installed and we mostly likely don't have a filter drier on our other system (although that one's been functioning ok). I looked at the documentation for this unit and the filter drier is listed under optional equipment but another page says it is suggested in all field-connected split-system heat pumps. Can the absence of this filter really cause the issue? If so, is this a major mis-step of the installers to not put it in?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@gmail.com wrote:

Many condensing units have a small factory installed liquid line dryer inside the housing. On any of the systems me and my guys install or disconnect for repair, we in install a replaceable liquid line dryer and sight glass with a moisture indicator. Using flare fittings and sealer called Leak Lock makes it easy to replace the dryer or attach fittings for blowing out the lines or pressure testing. Another product I often use on sticky valves is Supco88, it's like Liquid Wrench for refrigeration and AC units.
http://www.supco.com/Chemicals%20pg7.htm
Injecting Supco88 into your system could help free up the reversing valve, expansion valve or clear a clogged port if that what is causing the problem.
[8~{} Uncle Monster
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The tech "felt" the TXV was bad? That's a sure sign of a hack. And without the data Bryant's telephone diagnosis isn't any better.

Yep, your system was hacked.

How do these numbers compare to the specs for this system?

That's because the reversing valve isn't the problem.

With an 18 degree delta T I'd say the TXV is working OK.

As we know, the original installer is a hack. However, the absence of a filter dryer in a properly designed and installed split system isn't fatal in and of itself.
Did you ever get a look at the heat load calculation that the installing company did? Oh yes, that's right... they are a hack. How about the return and supply plenum temperatures? You still might have a return-side duct leak.
The most recent tech seemed to have the most scientific approach to diagnosis; maybe his company can do a heat load calculation for you and tell you if your system is correctly designed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.