TXV Whistling

[Myrmydon]

We have sold 5000 heat pumps this year. Out of 5000 I have 4 that are creating a whistling noise that appears to come from the TXV. We have replaced the TXV, replaced the condenser section, inspected the line sets and evaporator but the noise is still present. has anyone here ever encountered this?

[Brian_UK]

Hi and welcome to the forum.

Haven't got any brilliant answers I'm afraid...

Sounds like the only part you haven't changed is the evaporator section. Is the TXV in the outdoor or indoor unit?

Is it possible that some form of harmonics is being set up in the pipework/coil after the TXV ?

[paul_h]

I've had a few like this, it's normally caused by a tail protruding into the pipework too much. Eg the 1/4" factory welded up charging tail stub, or the schrader port welding into the suction or discharge lines.
Try and track it down using a screwdriver or stethescope to your ear and onto the pipework. You can normally hear at least which pipe it's on by how loud it gets.

[Grizzly]

Paul H.
Iv'e been reading some of your posts.Respect you know your stuff!
Cheers Grizzly.

[tonyelian]

dear myrmydon
i think if the distance between and it need a long piping and there is too much elbows that could be the problem or else i agree with paul
best regards tony

[nike123]

We have sold 5000 heat pumps this year. Out of 5000 I have 4 that are creating a whistling noise that appears to come from the TXV. We have replaced the TXV, replaced the condenser section, inspected the line sets and evaporator but the noise is still present. has anyone here ever encountered this?

What type of heat pump is yours. Does this happening both in cooling and heating?

[Andy]

We have sold 5000 heat pumps this year. Out of 5000 I have 4 that are creating a whistling noise that appears to come from the TXV. We have replaced the TXV, replaced the condenser section, inspected the line sets and evaporator but the noise is still present. has anyone here ever encountered this?

Hi Myrmydon

what is the subcooling like on the liquid entering the valve. Vapour instead of liquid would whistle.

Possibly incorrect refrigerant charge, or a poor pipe connection on the condenser.

Or something boiling the liquid into vapour on the liquid line.

Anyway I would check the liquid subcooling.

Kind Regards Andy

[zenen]

we have a similar whistiling on a Package unit AHU. the whistling it stop and starts continuesly.

[Emmett]

I agree with Andy, in my experience whistling = vapour