H-38, 2007 This is our first boat with air conditioning and it is great, but, the forward unit freezes over with ice and blocks the air flow. Does this mean the unit needs to be serviced or there is just too much moisture in the air for it to handle? Any similar experience or advise?
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Service
I have AC one unit on my 36 and run 24-7 lately and it does not ice up at all,keeps boat nice and cool. Nick
I have AC one unit on my 36 and run 24-7 lately and it does not ice up at all,keeps boat nice and cool. Nick
Give this a try
Friend of mine had the same problem and factory told him to wash the coils with Cascade dish washer detergent? Apparently it makes the condensation slide off the coils or not freeze or something. Anyway he did it and it's worked fine ever since.
Friend of mine had the same problem and factory told him to wash the coils with Cascade dish washer detergent? Apparently it makes the condensation slide off the coils or not freeze or something. Anyway he did it and it's worked fine ever since.
Hmm, worth asking dealer service (warranty)
When it's hot/humid, the units in our H41 (2005) go in to a non A/C mode for about 40 seconds every now and then, apparently to melt any ice buildup during hot humid weather. We get a blast of warm, moist air out the vents while it's happening. Your unit is probably different brand (ours are Polar Bay, which no longer exists as a company). Ask your service department, especially since it is under warranty.
When it's hot/humid, the units in our H41 (2005) go in to a non A/C mode for about 40 seconds every now and then, apparently to melt any ice buildup during hot humid weather. We get a blast of warm, moist air out the vents while it's happening. Your unit is probably different brand (ours are Polar Bay, which no longer exists as a company). Ask your service department, especially since it is under warranty.
some things to check
A/C units freeze up at the coils for only two reasons: insufficient airflow or low coolant. Presuming this is a new boat, I'd ignore the latter possibility and conssider air flow. First, if the unit was installed backwards as I've seen done, it will freeze. The orientation should be such that fresh intake air is drawn across the coils to the back of the unit where the heat exchanger is located. Assuming it was installed correctly, too much or too little air can also cause freezing. Make sure there is an unblocked fresh air intake of the appropriate size (see install instructions). It shouldn't freeze regardless of the ambient temp or cycling to heat setting if it is getting good airflow.
A/C units freeze up at the coils for only two reasons: insufficient airflow or low coolant. Presuming this is a new boat, I'd ignore the latter possibility and conssider air flow. First, if the unit was installed backwards as I've seen done, it will freeze. The orientation should be such that fresh intake air is drawn across the coils to the back of the unit where the heat exchanger is located. Assuming it was installed correctly, too much or too little air can also cause freezing. Make sure there is an unblocked fresh air intake of the appropriate size (see install instructions). It shouldn't freeze regardless of the ambient temp or cycling to heat setting if it is getting good airflow.
Replace or wash the filter
As Don indicates, this is usually due to insufficient airflow. Most of the time, it is due to a dirty filter; and it does not have to be very dirty to freeze the coils. Allan
As Don indicates, this is usually due to insufficient airflow. Most of the time, it is due to a dirty filter; and it does not have to be very dirty to freeze the coils. Allan
Low Refrigerant charge
Get someone to check the freon charge. That is usually the problem on home air conditioning units also. Check your air flow if you need to eliminate that, but, it's the charge.
Get someone to check the freon charge. That is usually the problem on home air conditioning units also. Check your air flow if you need to eliminate that, but, it's the charge.
Forward ac unit on 38 will freeze up
when humidity is high IF you are trying to bring the temp down too quickly, or if like me, you sometimes carry on conversations with dockmates with the companionway hatch open. When first turning the unit on set the thermostat about 6 degrees below ambient, let the unit cycle to that temp and then set the stat lower. This gives the unit a couple of cycles to dehumidify the cabin before you take the temp on down. Do not expect to have cabin temps like a meat locker when outside air is pushing 95. When daytime temps are that high, we usually set the stat around 78 after the initial cool down. We are running two Marine Air units (4000 BTU aft and 15000 BTU forward) in our 2005 38 Steve and Sheila Kamp Carolina
when humidity is high IF you are trying to bring the temp down too quickly, or if like me, you sometimes carry on conversations with dockmates with the companionway hatch open. When first turning the unit on set the thermostat about 6 degrees below ambient, let the unit cycle to that temp and then set the stat lower. This gives the unit a couple of cycles to dehumidify the cabin before you take the temp on down. Do not expect to have cabin temps like a meat locker when outside air is pushing 95. When daytime temps are that high, we usually set the stat around 78 after the initial cool down. We are running two Marine Air units (4000 BTU aft and 15000 BTU forward) in our 2005 38 Steve and Sheila Kamp Carolina
One more vote for having the coolant level checked
I've had a few air conditioning units freeze over (admittedly not on a boat though) and it's always been due to low coolant levels. Trying to bring the temp down too fast magnifies the problem. Manny
I've had a few air conditioning units freeze over (admittedly not on a boat though) and it's always been due to low coolant levels. Trying to bring the temp down too fast magnifies the problem. Manny
I vote A/C tech.
A/C units will vary but a quality unit will have a low pressure switch that shuts the unit down if the charge is to low. It will also have a thermistor probe mounted low on the evaporator coil (coils freeze from the bottom up) to cycle the compressor to prevent freeze up. Let someone who has been there /done that take a look. Just my 2 cents... Have a great day!
A/C units will vary but a quality unit will have a low pressure switch that shuts the unit down if the charge is to low. It will also have a thermistor probe mounted low on the evaporator coil (coils freeze from the bottom up) to cycle the compressor to prevent freeze up. Let someone who has been there /done that take a look. Just my 2 cents... Have a great day!
One cheaper thing...
Make sure all your vents are open and clear. If not enough air is moving over the coils they will freeze up. Mermaid's trouble shooting list starts with this one. /Eric Jones Foxfire
Make sure all your vents are open and clear. If not enough air is moving over the coils they will freeze up. Mermaid's trouble shooting list starts with this one. /Eric Jones Foxfire
on our boat
on my 2003 420 it has happended twice. Both times I cleaned the filter which solved the problem
on my 2003 420 it has happended twice. Both times I cleaned the filter which solved the problem
MKing
makes a good point. The capillary tube for the expansion valve should be attached to the bottom of the evaporator coils. This controls the expansion valve during ice-up and allows the system to thaw before continuing. If it is working correctly your evaporator should never ice-up. A good tech will easily find your problem.
makes a good point. The capillary tube for the expansion valve should be attached to the bottom of the evaporator coils. This controls the expansion valve during ice-up and allows the system to thaw before continuing. If it is working correctly your evaporator should never ice-up. A good tech will easily find your problem.
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