A/C freezing up

[Geo_D]

So Z-Bail...did you have long term success with this? Reading your posts were like looking in a mirror, almost to the letter. I caught on to running the blower on "on" early on. It would cool for 7-10 days, but ultimately freeze over again. The tech always instructed me to run it on auto and within 24 hours the coil/TXV would freeze. Just replaced the t-stat, ran on auto and it froze the next day. Tech is thinking it's the board for the blower. He's stumped and has brought it to his companies tech group. Would love to hear if you had long term success.

[beenthere]

Made this its own thread. You are not permitted to post in other peoples threads in the AOP forums, please read our site rules, thank you.

[udarrell]

So Z-Bail...did you have long term success with this? Reading your posts were like looking in a mirror, almost to the letter. I caught on to running the blower on "on" early on.

It would cool for 7-10 days, but ultimately freeze over again. The tech always instructed me to run it on auto and within 24 hours the coil/TXV would freeze.

Just replaced the t-stat, ran on auto and it froze the next day. Tech is thinking it's the board for the blower. He's stumped and has brought it to his companies tech group. Would love to hear if you had long term success.

Probably inadequate airflow heatload going through the indoor coil.

If outdoor temp gets too low pressures will drop too much with a piston metering device & indoor coil pressures can drop below freezing point.

Replacing piston with TXV could be helpful, plus increasing indoor airflow through coil & not setting thermostat too low.

A two speed condenser blower motor that drops the CFM when temps go below a certain point would help...

[Geo_D]

Probably inadequate airflow heatload going through the indoor coil.

If outdoor temp gets too low pressures will drop too much with a piston metering device & indoor coil pressures can drop below freezing point.

Replacing piston with TXV could be helpful, plus increasing indoor airflow through coil & not setting thermostat too low.

A two speed condenser blower motor that drops the CFM when temps go below a certain point would help...

So thanks for your help. Curious how Z-bail's issues resolved themselves. Here's how mine did. Brought in another tech who indicated there was leak at the dryer and restriction at either TXV or in coil. Changed out both, tested coil-no restriction, charged system, all ok and back in the cool. Did mention adding more return air capacity which will happen (changedfrom 4ton to 5ton years ago but kept return air the same). Ultimately will change to two stage blower.