FHP expansion valve problem

[hovak]

I have been asked to take over a bldg. w/ several florida heat pumps wich 9 units have had expansion valve failures apparently! Before accepting the work wondering if anyone has had any problems similar with FHP unit water to air 3-6 ton. I am obviosly concerned that they were diagnosed properly but the previous contractor is very reputable

[mo geo man]

Have had a couple, 9 in one building does seem a bit high. We have seen some water flow issues give simular symptums.

[Moose87]

Have had a couple, 9 in one building does seem a bit high. We have seen some water flow issues give simular symptums.

i would have to agree with geo man . Ive had 12 carrier wshp that were giving the same symptums and turns out to be water flow issue.

[GT Jets]

Had one today on a two stage FHP (20 ton) one bad valve, the other works perfect, same water on both compressors...

GT

[techservices]

I have to replace the power heads on many FHP 10 to 20 tons
They do not appear to have a separate circuit for heating
The TX appears to be Bi-Directional, no check valve.
Yes they fail often on units less than 5 years old.
Only good thing is that they let me know the TX power head is bad by
showing a low suction pressure with a very high discharge pressure of over 290 Pounds.
It could be that the Sporlan kt style Expansion valve elements are faulty to
begin with.
At any rate they appear to have a high failure rate.

[Tempted]

Ok so many of us are replacing those tx's. Some of us are not getting the unit running even after replacement. I'm going to work on a problem unit that has never operated more the 20 minutes without tripping. In heat or cool now. My issue is a year old. I'm thinking water flow now. so thats what I'm going to revisit. If I recall my unit requires 12 gpm and the pump is sized right.
Same problems looks like a design issue with in the unit. TX or water flow restriction.