Is it the TXV???

[aruddick]

Havent installed one since the mid 90's. the owner thought every unit with txv needed one. i guess he was stuck in refrigeration mode.

[canesfanforlife]

Did adding 3lbs make the txv stop freezing?That does't make sense. the txv will maintain constant superheat regardless of an overcharge.

[aruddick]

bulb must always be colder than the power element or the valve's
body. If not, the charge can migrate from the bulb to the power element with a resultant loss of control <-----p-i found this on NET

The bulb has a seperate charge that due to raise and lower in line temp will overpower the evap and sping pressure to allow more ref to flow. I think you found bad info.

as far as problem, as long as the whole coil is getting airflow ( we have a problem with installers blocking off the leg of our carrier N coils, causing similar issues) then I would have to agree that replacing the txv would be a logical step.

[nikolce]

Did adding 3lbs make the txv stop freezing?That does't make sense. the txv will maintain constant superheat regardless of an overcharge.

it was freezing up still right after txv......when i was trying to add more 410a (after 4F subcooling ) freezing moved down where dist tubes wore anterying the coil......and then when i was done overcharging (at 25F superheat) no more freezing and if you lose txv bulb charge wouldn't the txv be in close position?????when txv bulb heat up do to suction pipe pressure in bulb becomes higher and pushesh agains spring and open to let more refrigerent.....when the bulb gets cool by suction pipe presure goes down and spring in txv closes the flow of refrigerent.....same as no charge at the bulb.......isn't?????? sorry for spelling im not good at english

[nikolce]

The bulb has a seperate charge that due to raise and lower in line temp will overpower the evap and sping pressure to allow more ref to flow. I think you found bad info.

as far as problem, as long as the whole coil is getting airflow ( we have a problem with installers blocking off the leg of our carrier N coils, causing similar issues) then I would have to agree that replacing the txv would be a logical step.

but the fact sys worked last summer.......and i checked the vents and return i the house ok....

[nikolce]

The bulb has a seperate charge that due to raise and lower in line temp will overpower the evap and sping pressure to allow more ref to flow. I think you found bad info.

as far as problem, as long as the whole coil is getting airflow ( we have a problem with installers blocking off the leg of our carrier N coils, causing similar issues) then I would have to agree that replacing the txv would be a logical step.

you miss understood the point i was thiking since the txv froze been coolder than the bulb which is on suction bulb charge magrate to powerhead....not the freon!!!!!

[aruddick]

you miss understood the point i was thiking since the txv froze been coolder than the bulb which is on suction bulb charge magrate to powerhead....not the freon!!!!!

Yeah missed that one. I wondered how anyone could sell that info. Ref 101 kills that. my bad. Not sure if the ref will migrate. If the line freezes then the bulb pressure would drop and the spring would force the valve closed. (if working properly)