To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.
The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.

problem with carrier heat pump

does anyone know if the txv used on a carrier air handler model# fk4dnb006 has a internal check valve? i worked on one today matched with a 38ykc048 heat pump that works fine in the cooling mode,but when it is in the heating mode it immediately (within 30 seconds) freezes at the piston body,and the distributor on the outdoor unit.all four tubes that come off the outdoor distibutor freeze to the same degree.the only thing that i can think of would be a stuck (closed) check valve at  air handler. that would explain why it operates fine in the cooling mode.the unit will go into defrost,but by that time there is so much ice on the outdoor coil it times out before all the ice can clear the coil. any thoughts or suggestions would be much appreciated. thank you
· ·

Comments

  • dondon Posts: 395Member ✭✭
    bypass

    Take a look at the piping.if the txv does not have a internal check valve you would see a bypass with check valve going around the txv.If you do not see the bypass then it has a internal check valve.

    It possible you could have a stuck check valve on the indoor unit and if so you would see high head pressure if someone added freon before you.If not then it would be below normal with a suction pressure being low.

    I would start at the outdoor metering device.Check your superheat at the outdoor coil that would lets you know if she is starve for refrigerant.Then you have the filter drier that you could check temp drop across it to see if she clogged, all tho pressure taps would be far better for checking a clogged drier.

    Its been my experience when they freeze that quickly it low on refrigerant or the outdoor txv is bad.
    · ·
  • John MillsJohn Mills Posts: 531Member ✭✭
    Usually

    frosts at the point of the restriction. Might want to investigate the outdoor piston. I'd think if the issue were indoors, you'd see frost on the outlet of the TXV. 
    · ·
This discussion has been closed.

Welcome

It looks like you're new here. If you want to get involved, click one of these buttons!