TWedd
Veteran Member
- Joined
- Feb 17, 2019
- Messages
- 72
- Location
- United States
- Vessel Name
- Sweet Lu
- Vessel Make
- Marine Trader sundeck
Frosting is caused by low evaporator coil temp. This will not be caused by the pump in cooling mode. Three possible problems:
1 Low on refrigerant. too much refrigerant will not cause frosting. New unit so this is the least likely cause, but still possible.
2 Low air flow- most likely cause. do every thing you can to remove restrictions from the air flow, the fan on these units do not like inlet airflow resrictions at all so remove as many restrictions as possible. checking the supply ductwork also is a good idea, however the fan can push more thru the supply duct than they can pull thru the return.Dirty air filters are the most common cause of frosting but not the issue on this new install. check with the MFG to see if your supply duct work is within limits.
3 Low entering air temp. once the entering air get below 70* the unit will be more likely to start frosting. check the temp of the entering air when frosting. if it is below 70* adjust the thermostat to cycle the unit off before it reaches that temp( 70* is a bit conservative, 68* is the lowest you should see, but that is pushing it)
1 Low on refrigerant. too much refrigerant will not cause frosting. New unit so this is the least likely cause, but still possible.
2 Low air flow- most likely cause. do every thing you can to remove restrictions from the air flow, the fan on these units do not like inlet airflow resrictions at all so remove as many restrictions as possible. checking the supply ductwork also is a good idea, however the fan can push more thru the supply duct than they can pull thru the return.Dirty air filters are the most common cause of frosting but not the issue on this new install. check with the MFG to see if your supply duct work is within limits.
3 Low entering air temp. once the entering air get below 70* the unit will be more likely to start frosting. check the temp of the entering air when frosting. if it is below 70* adjust the thermostat to cycle the unit off before it reaches that temp( 70* is a bit conservative, 68* is the lowest you should see, but that is pushing it)