Bad A/C reversing valve?

Aug 31, 2007 91 Replies

We completed construction on our home in Florida in 7/2006. We have 2 Bryant central air units (one 3 ton unit and one 4 ton unit). Last week I noticed the 3ton unit couldn't keep up with the cooling during the afternoon hours. I called the A/C company that put the units in during construction. Here is what happened:



Visit 1: (last week): the tech tells me the system is low on freon either because it was never filled properly or there is a leak (they'll test for the leak if it gets low again and the problem resurfaces). I received a bill for $90 and was told the unit would catch up that night then should be fine. The tech noted that air was now coming out 16 degrees cooler than when going in so I should now be fine.



Visit 2: after I called and advised there was no change the boss sent out his "best diagnostician" who "made some adjustments" with the air handler which is up in the attic and noted we now had 18 degrees of cooling and the unit would be fine once it catches up tonight, but again there was no change.



Visit 3 (today): the boss decided to send a team to figure it out, the



2 original techs plus one more. They each seemed to have their own diagnosis of the problem based on what my wife had overheard (unfortunately I wasn't around the whole time). They had simply told me the plan was to gather info and have Bryant diagnose the system. Now I'm told the reversing valve needs to be replaced to the sum of $720 even though the unit and part is under warranty (I'm told it's a lot of labor to replace it).

I called another company who will come in the morning for a free estimate/2nd opinion. They told me the problem didn't sound like something caused by a bad reversing valve but they'd come out and see. I'm looking for any advice on how to proceed with and what questions I should ask, as I'm looking at a lot of money and not confident these guys know what the real problem is.



It could be anything but you would think that the problem would be under warranty.

Allot of the times you can play with the paper work to get it under warranty if it that close.

Let us know what they find.

Ohhhh that should be fun. Be sure to report back and tell us what you learned.

"Edwin Pawlowski" wrote in news:g92Ci.1453$3Y1.1256 @newssvr17.news.prodigy.net:

Maybe he already knows how to ignore abusive folks?

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

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.

Most manufactures have a 5 yr parts warranty. And most reputable HVAC companies will take care of the installation costs when it's just over a yr old.

But, then again, the company isn't reputable or they wouldn't be relying on Bryant to diagnose a unit they installed!!!!

Like yourself, who offers the OP no useful information.

wrote in news:2796a$46d947f0$9440c41e$20135 @STARBAND.NET:

I did offer the OP useful information. The information is: posters in alt.hvac are generally abusive in nature. You are a prime example.

So now you are wrong one more time. Will you ever learn?

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.

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.?

I already know that you're an idiot. Looking for a cookie?

wrote in news:e70bb$46da2c0c$9440c41e$24038 @STARBAND.NET:

Wait right here. Someone will come along and explain it to you.

No explanation needed, you're an idiot.

wrote in news:49c74$46da44a4$9440c41e$30781 @STARBAND.NET:

Sounds about right coming from someone who believes that local code can only be more restrictive than model code. Just keep saying it and maybe some day it will be true. GOOD LUCK.

news:g92Ci.1453$3Y1.1256

Are you looking for your donut?

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 s*it

wrote in news:b3a00$46dae4ed$9440c41e$ snipped-for-privacy@STARBAND.NET:

Typical nonsense response from a psychotic individual. Get help now.

news:b3a00$46dae4ed$9440c41e$ snipped-for-privacy@STARBAND.NET:

Makes more sense then your inaccurate bullshit.

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