low head pressure and suction pressure cut out

[pony]

run in to something need some input,i work on my friends carrier 2 tons r410a heat pump with r410a goodman 2.5 tons indoor,heating mode running fine,but wehen i switch to cooling mode,the pressure bothside start dropping down to cut out limit in 30 secs(highside 47lbs,lowside 23lbs,refrigerant is not flowing),indoor is fix orfice,out door is r410a 2 tons txv valve,believe it is bad restriction somewhere,airflow is fine(high speed),no chance check SC or SH,take txv out and blow all the line,and check txv any object inside the body it appear clean,before i take txv apart,i even try to adjust the txv let more refrigrant flow ,but it didnt help,maybe indoor fix orfice problem?what ur will look first?and sorry if i dont have enough information,please ask,thanks

[SuperDave89]

is the reversing valve energizing all the way?

[John Markl]

It's kind of hard to understand your post, but it sounds like maybe the outdoor TXV is not allowing the refrigerant to flow the other direction, or there is a bypass check valve that is not working. From the pressures listed, it sounds like it is in essence "pumping down".

[just_opinion]

run in to something need some input,i work on my friends carrier 2 tons r410a heat pump with r410a goodman 2.5 tons indoor,heating mode running fine,but wehen i switch to cooling mode,the pressure bothside start dropping down to cut out limit in 30 secs(highside 47lbs,lowside 23lbs,refrigerant is not flowing),indoor is fix orfice,out door is r410a 2 tons txv valve,believe it is bad restriction somewhere,airflow is fine(high speed),no chance check SC or SH,take txv out and blow all the line,and check txv any object inside the body it appear clean,before i take txv apart,i even try to adjust the txv let more refrigrant flow ,but it didnt help,maybe indoor fix orfice problem?what ur will look first?and sorry if i dont have enough information,please ask,thanks

If you had your gauge on the liquid line port and true low suction port, then the OD TXV is not a bi-flow TXV.

To test this, take the guts of the TXV out and run it in cool mode, the pressure will be OK.

[madblack]

if the indoor fixed orifice is plugged, it will pass gas in heating mode , but choke off in cooling mode, together with cool outdoor temperature this would result in pressures you have described. pump system down to outdoor unit, (including liquid line through your manifold) and check center of metering device , I am assumeing it is a piston type .

[SuperDave89]

I also agree it could be a bypass check valve issue. I woul also run the unit in the cooling mode with the blower off and see if where the indoor metering device and feeder tubes might start freezing up if you can keep it running long enough.

[pony]

i checnk the reversing valve it feel like it work,cause i put it in cooling mode,and it cut out in 30 seconds like before,and i disconnect the wire to reversing valve,and it have loud sizzling sound,so i know the valve is moving,that sound right,and it does have 24 v to reversing valve coil,what to look next?compressor?it does pump down,and 3 leags elec reading is normal(2 - 3 ohmes)?

[pony]

PROBLEM SOLVED,THE NEW OUTDOOR TXV I PUT IN IS BAD TXV,IT WILL WORK ON HEAT MODE,AND COOLING MODE INLET SIDE PRESSURE IS GOOD,OUTLET SIDE IS DROPPING FAST,THANKS FOR ALL THE TIPS.SHARE THIS WITH EVERYBODY.

[woody19]

PROBLEM SOLVED,THE NEW OUTDOOR TXV I PUT IN IS BAD TXV,IT WILL WORK ON HEAT MODE,AND COOLING MODE INLET SIDE PRESSURE IS GOOD,OUTLET SIDE IS DROPPING FAST,THANKS FOR ALL THE TIPS.SHARE THIS WITH EVERYBODY.

I must have missed something here. What is the model of the Carrier hp you are working on? I have never seen a Carrier hp that uses a TXV to meter flow to the cond. unit, there is a piston inside the 3/8 service valve that meters flow during the heat cycle. And the TXV at the coil meters during cooling cycle. What have I missed?

[second opinion]

You caught the same thing, Carrier uses piston on outdoor unit

[TACKERDOWN]

wonder what the head pressure should be at with a 410 system in cooling it's 32 degrees (f) out in pa

[John Markl]

We had one today similar.....ran fine in heat mode, but when it flipped to defrost, it "pumped down" and shut off on low pressure. Indoor TXV bad.

[JWadelHVAC]

Yes. What Carrier heat pump has a TXV from the factory?