high head pressure low suction

beenthere

Trane uses check valves instead TXVs with built in checks.
A hold over from when they boought GE.

ICP also uses, or used check valves.

They are installed in a line the by passes the metering device when it switches to the opposite mode of what that metering device is for.

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How many times must one fix something before it is fixed?

bwalley

The Trane FCCV is the metering device.

On the 13 SEER and above they are not used, they now use a TXV.

RoBoTeq

I understand that. Not ever having been a Trane dealer, I don't know that Trane did not do the same thing.

beenthere

Talking about the older ones, that used seperate metering and checks.

__________________
How many times must one fix something before it is fixed?

RoBoTeq

Ahhhhhh (the bell chimes)

You are talking about the bypass check valve that goes around a metering device when the coil is being used as a condenser.

Check valve goes bad and opens, oversized metering.......

.......would cause low head and high suction.

bwalley

In this case the guy had high head pressure and low suction pressure, which leads me to believe it is non condensibles.

beenthere

Ya, that be the one.

I didn't mean to imply that is what is wrong in this case.
just answering anotehr poster that never heard of it.

__________________
How many times must one fix something before it is fixed?

RoBoTeq

That is what I am figuring on as well, which is why I suggested emptying the system of refrigerant, changing out the filter/drier and evacuating to remove any and all non-condensibles. This would require the system to evacuate to below 500 microns but not below 250 microns and to hold below 1000 microns with the evac pump off.

RoBoTeq

I understood that. I just was not getting where the check valve was located until you brought up the metering by-pass.

hvactech

the check valve must only be used on heat pumsp? and up here in MI we dont see too many heat pumps! my lack of experience in this really shows now LOL

bwalley

The FCCV are in Pre 13 SEER, straight cool systems,Trane and American Standard units as well.

RoBoTeq

What does FCCV stand for? I assume the second C and V stand for Check Valve, but what does the FC stand for? What was the function of this check valve.

bwalley

Flow Control Check Valve

RoBoTeq

So this FCCV was actually the metering device?

Sounds more like a fancy name for a piston.

bwalley

Yes it is the metering device for the indoor coil, it does more than act as a fixed orifice metering device, that is why it is called an FCCV.

mechanicalDvr

I have worked on thousands of heat pumps and haven't heard of that term "FCCV", it means nothing to me.

bwalley

Ever work on GE Weathertron, American Standard or Trane units?

mechanicalDvr

I have worked on many of them but most had TXVs. I go back to the old tan GEs with the controls in the top shell with the linset coming out the very bottom. I am close to 50 and have been doing this stuff since I was a kid in a family run business, where if you could walk you could work. I got a loaded toolbox for Christmas at 5 yrs old.

scooter

has any body heard from tc yet wether or not he found any thing?

RoBoTeq

What else does it do? Is it electrically operated? Thermally? Does it change the metering somehow?