Is there anyone out there who has a Dometic roof mount AC that, although everything works right (thermostat, compressor, etc) that it's not blowing as cold as it did three years ago? Using a little logic, it seems that the coolant level needs to be "topped off". However, having a mobile tech come look at it, he says that it doesn't have a tap. I've got to assume through reading that tapping it and then putting the correct version of coolant into it would take care of the problem instead of having to purchase a new one. As a sidebar, it torques me off that this may be the only solution due to the way the AC unit was designed. Anyone?
Dometic roof air conditioner
- Thread starter Cands
- Start date
RV rooftop air conditioners do not have the ports to "top off" the refrigerant.
If the refrigerant is low then there must be a leak somewhere. The technician would have to add the ports and identify and repair the leak. If that's even possible.
Bottom line, replace it.
Peace
Dave
If the refrigerant is low then there must be a leak somewhere. The technician would have to add the ports and identify and repair the leak. If that's even possible.
Bottom line, replace it.
Peace
Dave
As I've read, putting a "tap" into the line would work in order to add the refrigerant. Was just wondering if anyone else has done this. Seems like a total rip off to build an AC unit that is "disposable" after only about three years due to designing it so that it can't be corrected in a simple manner that is congruent with logical practice.
danemayer
Well-known member
May not be a leak. Cooling is about moving heat from inside to outside. Air has to move freely for that to happen. Make sure your return filters are clean and remove the shroud on the roof to inspect and clean the condenser fins. 2 cautions: when removing the shroud, assume you'll disturb a nest of wasps or other insects - don't jump off the roof, and be gentle with the fins - they're very soft.
Yep. Did all that. The only thing jumping off the roof is me due to having an AC that ought to last a little longer than the milk in my fridge.
jerryjay11
Well-known member
An RV AC unit is built similar to a window AC as both are hermetically sealed units, just as a refrigerator or dehumidifier are, and work the same way. Yes they can have service valves installed and refrigerant can be added, but the cost of a tech to do this would bring it closer to the value of a new unit. Being in the HVAC business since to mid 70's and dealing directly with manufacturers I can say it isn't an intentional design flaw to make the units break in just a few years. That would be bad product advertisement. What I would do since it is only 3 years old is contact Dometic as some models carry a 3 year warranty. Even still if not, they may cover it anyway to protect their brand.
michaljhon
Member
I don't have any information about it. For roof air conditioning I always contact luxe air conditioning. I will also recommend you to if you are in Aus just contact them. They can guide you properly.
wdk450
Well-known member
Are you getting the minimum 20 degrees of cooling between the warm air intake air point and the output nearest to the air conditioner? That is a pretty good measure of your air conditioner's cooling functionality. What are the ambient temperatures you are cooling in? Very high ambient temperatures (110 degrees and above) can cause the compressor overtemperature switch mounted on top of the compressor to open, and you you lose all cooling function in the middle of a high heat episode. If you are in a very sunny locale, you should look into reducing your RV's solar heat gain with reflective roof and window coverings.
Ok. For all of you that either told me to buy a new one or simply clean a filter, know that I had an HVAC guy come out who put freon in it and it's running and cooling like new. So, apparently conventional wisdom was wrong in that you can install a tap and refurbish the unit just like a car. Took 20 minutes and $150.
danemayer
Well-known member
RV techs aren't trained and most probably don't have the equipment to add Freon. As you found, if you can get an HVAC guy to help, it's possible to add taps. However, the leak is supposed to get fixed before adding Freon. Hopefully your guy did that. If not, you'll be calling him back next year.
Perhaps. But, having someone come out at an inderminate year is still cheaper and easier than replacing a unit for no less than $1k every 3 years. By the way, it was 4 ounces that brought it back to life. Not many people throw out a home HVAC unit every 3 years and not many cars lose their ac in 3 years, why would a roof air conditioner bedifferent?
I suppose everything leaks in the future. However, in visitation with others who have the same problem, it seems the best and most logical reasoning is to reload it with freon rather than buying an entirely new unit. In that regard, I wonder pushed the "buy another unit" rather than try to refurbish the one you have idea? Sounds like a wives tale built around a phony sales scare. As far as illegal, is there such a thing as "freon" police out there?
jerryjay11
Well-known member
If my memory serves me right any appliance using more than 50 pounds of refrigerant must be repaired. For anything less then a earnest attempt to find the leak and repair is the recommended solution. Those HVAC refrigerant certified techs that fail to adhere to the regulations governing refrigerants are subject to a fine of $10,000 (as I remember) and lost of certification. Now it's been a few years because of retirement, but the idea of a hefty fine and loss of certification keep me on the up and up. But getting it done for just $150 is outstanding. Though I doubt the tech found the leak and with luck you will get another 3 years before it has to be done again.
Filters in RVs that are clogged with dirt and debris will perform less efficiently. Knowing how to do this on our own will save us both money and time.
After 14000 miles, an air conditioner filter's life cycle is over, and any filter that reaches this point is no longer filtering properly. After this road trip mileage or if the filter is found to have holes upon inspection, you should acquire a new one from your RV center.
After 14000 miles, an air conditioner filter's life cycle is over, and any filter that reaches this point is no longer filtering properly. After this road trip mileage or if the filter is found to have holes upon inspection, you should acquire a new one from your RV center.
Roller4tan
Well-known member
Yearly air conditioner maintenance is always required. My 2014 Bighorn has two ac units. Last summer I had to get up on the roof, again and clear the dirt and debris from the condenser and straighten the fins. The unit was overheating and shutting down. The filter is checked and cleaned weekly when in continuous use, but condensation on the fins tend to accumulate smaller particles over time. You have to be a GOOD handyman to own these money buckets......
The filters should be cleaned every two weeks, according to the manufacturers' recommendations. However, if you are only using one campground, you can only clean it once per month.
You must clean the filters more frequently, probably once per week, if it is windy or you have respiratory issues, to make sure the air is clean and safe.
You must clean the filters more frequently, probably once per week, if it is windy or you have respiratory issues, to make sure the air is clean and safe.
2019_V22
Well-known member
Since I don't want to type this again, here is a link to a post I did here regarding cooling on a rooftop unit.
https://heartlandowners.org/threads/a-c-freezing-and-making-ice.82286/#post-663232
Keep in mind that if you needed Freon, you most likely have a leak, as mentioned 410A is a blended (1 or more compounds) refrigerant which, when leaked will throw the blended recipe off. Topping off, continues to alter the blend recipe, and will eventually cause issues due to that.
https://heartlandowners.org/threads/a-c-freezing-and-making-ice.82286/#post-663232
Keep in mind that if you needed Freon, you most likely have a leak, as mentioned 410A is a blended (1 or more compounds) refrigerant which, when leaked will throw the blended recipe off. Topping off, continues to alter the blend recipe, and will eventually cause issues due to that.
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Daley07
Active Member
Have used this Dometic 640315C air conditioner on my 2017 Forest River Vibe for 2 years. I also have some problems with the cool unit. The main reason comes from the vents, tubes, and other air conditioner components for signs of blockage or clogging. In addition, dirt, debris, and other contaminants can make the air conditioner work harder, reducing the cooling efficiency.
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