Dometic AC potential issues

[dpgllg]

SEE UPDATE ON PAGE 2

My Dometic AC froze up while camping last weekend. I would let it thaw and it seemed to work for awhile and then freeze up again.

When we got it to the storage yard I took the inside cover off and discovered that the Freeze control sensor was not connected. I ordered a replacement and brought the RV home so I could plug it in. I replaced the sensor and the air is moving but it does not seem that cold to me.

I made sure that the baffle between the warm and cold air was in place and not leaking. The AC is putting water out across my roof as expected.

My brother looked at it and he said "maybe" the compressor is going bad. I have no clue how to tell if the compressor is having issues.

This AC is 25 months old so it shouldn't be worn out. I have already talked to Dometic and they are going to extend my warranty to get it repaired or replaced but I have to wait for an appointment anywhere between 4 to 6 weeks to get into the shop.

While I'm waiting is there anything else I can do to troubleshoot the AC? I'm going to let it run awhile to make sure that the freeze up is resolved. If it does freeze up again then it's possible that the Freon is low. Since it is a sealed unit then a replacement would be required.

Thanks in advance for your assistance!

Dave

[dpgllg]

[COLOR=]UPDATE UPDATE UPDATE

OP Here,

While waiting to find a service facility I kept working on the AC. I replaced the control board and thermostat as I obtained one at a reasonable price and it was fairly easy to replace.

After the replacement the air was not that cool and after running overnight it froze up the next day. The place I was going to call this morning has absolutely horrible reviews online about 9 negative to 1 positive including theft vandalism and poor repairs. I won't risk taking my RV there.

My selling dealer is mid November on getting me in and we are supposed to be in Disney November 8th. Other places are December and January.

Since I have already replaced everything else I have ordered a replacement upper unit which will arrive this Thursday. My brother and several of his friends / coworkers are coming Saturday to install it. I'm hoping that everything goes well and we will be able to travel again soon.

I will provide another update once installed.

Dave

[egrove]

Most likely have a refrigerant leak. Mine had same behavior (freezing up, not much cooling between intake and output). Had to replace whole unit. Some people can find leak and fix and refill, but this isn't recommended and considered a short term fix.

[dpgllg]

SEE UPDATE BELOW

OP Here,

An update on the AC unit. It has not froze up again BUT I do not believe it is working as it should.

Things that I have done so far:
1. Replaced Freeze sensor.

2. Made sure upper unit was clean and free of debris.

3. Made sure drain holes onto roof were free.

4. Verified squirrel cage and main fan operate.

5. Cleaned interior filter

6. Put thermometers on interior air intake and one on the output vents. Less than 5 degree difference in temperature. Temperature at output vent was 76. Thermostat set to 66. AC only shuts off around 2 or 3 in morning when outside temps are in mid 60's. If outside temp is above 70 does not shut off.

7. Spoke to Dometic. They are going to extend warranty until I get it into a service center for inspection.

8. Called multiple service centers including selling dealer. Selling dealer is 3 hours away and has a 8 to 12 week wait. Of the 4 dealers close by one refuses to work on Dometic because they will not pay him and ship defective replacement parts. The 3 others will work on it BUT I have to pay up front and then seek reimbursement from Dometic. Dometic refused this option. All local dealers also have a minimum of 5 to 6 week wait just to be seen. # of the dealers believe the upper unit needs replaced based on symptoms.

9. One dealer Dometic recommended (45 minutes away) will accept warranty but the person who does the work is semi-retired and only comes in when he wants. I have to call back on Monday to see if he might be coming in next week. If he decides to come in then there is a chance I could get it looked at next week.

So I'm going to shut the AC off and wait and call Monday.

I'm just afraid that the rest of the camping season will be lost while this issue is resolved.

Dave

[dougrainer]

It is very difficult to find a correct website to list all the components needed.
This is the CT tstat KIT Dometic 3316230.000 RV Single Zone CT Thermostat w/ Control Board Kit White
1.You need the upper 15k in black--Dometic Brisk Air Air Conditioner, 15K BTU, Black
2. You need the CT single zone kit
3. You need the interior mount kit which is this--Dometic 3105935.047 Quick Cool Ducted A/C Ceiling Assembly
So, you need 3 separate parts. Doug

[dpgllg]

OP here,

I started looking at getting a 2nd AC unit installed but I need to know what all parts that I would need. I want a Dometic 15,000 BTU Brisk Air II unit with black / dark shroud. This would be a ducted system with thermostat. My 5th wheel is prewired including the thermostat wire.

I have found the upper roof top units and I know that I need a ceiling assembly for inside and a thermostat. I think that there is a control box as well but I have no clue what actual part number that is.

Is there anyplace online that lists all of the required components? The local RV shops are all booked for the next 6 weeks so I want to at least know what is required and the cost of the parts before I take it in.

Thanks!

Dave

[dougrainer]

dpgllg wrote:
"A 15k AC in a 32 foot RV will NOT cool the RV."

OP here,

Do I need to add a 2nd AC? I thought you could only run one AC at a time? I do have 50 amp service. I am also prewired for a 2nd ac.

Is there a bigger more powerful ac than a 15,000 BTU AC?

Dave

If you have 50 amp service, then add the 2nd unit. Yes, they do build larger than 15k, but those are newer entry Brand units that do not have a track record. Most of the other brands ( NOT Dometic and RVP/Coleman), that entered the RV market in the past 15 years are no longer around. I would NEVER install any AC unless it was a Dometic or RVP. If the other brands go away, you cannot get parts or help. I believe the larger than 15k is around 16.5 or 17k. Still not enough extra BTU's to do the job you need done. You still need your existing AC checked out to make sure it is at spec and INSTALLED correctly. Doug

[dpgllg]

"A 15k AC in a 32 foot RV will NOT cool the RV."

OP here,

Do I need to add a 2nd AC? I thought you could only run one AC at a time? I do have 50 amp service. I am also prewired for a 2nd ac.

Is there a bigger more powerful ac than a 15,000 BTU AC?

Dave

[jkwilson]

dougrainer wrote:

dpgllg wrote:

dougrainer wrote:
1. The freeze Sensor not connected. WHY would you install a new one? Why not just install the old one?
2. They are sealed systems. IF you had a leaker, then ALL the coolant would have been gone by now. They only hold a 16 ozs of coolant.
3. Water Coming OFF the roof indicates the Unit is doing its job.
4. Your brother and you have no way to tell if the compressor is "going" bad:B FYI, your compressor is not going bad.
5. How hot is it and how big is your RV? Doug

OP here,

The end of the sensor did not have the flat blade attached so it broke off or whatever. To be safe it wasn't an expensive part so I replaced it.

I stated that I had no clue about the compressor. Was hoping for a little feedback if there was any simple way to determine any issue with it.

It was in the mid 70's now 80 at noon and the AC has not shut off at all.

It is a 32 foot 5th wheel and the AC is a 15,000 BTU unit.

A 15k AC in a 32 foot RV will NOT cool the RV. Especially if you have slide out/s. Period. The max size for a ducted 15k is about 27 feet. Don't listen to responders that state they have a over 27 foot that does cool with 1 AC. I am giving you 40 years experience with RV's and sizing of Roof AC units. You need to have a operational check of that AC unit. You need
1. The compressor amp draw at ambient correct temp
2. The Temp Differential between the closest cold air outlet and the return air filter. The temp Diff will be 19 to 22 degrees. IE -- 82 hot in 62 cold out would be very good. Doug

My Atwood did a fine job in August of 2017 when we could only get a 30A site for the eclipse. 95, humid as heck and no shade in the middle of the day. It worked hard, but kept it in the 70s.

[dougrainer]

dpgllg wrote:

dougrainer wrote:
1. The freeze Sensor not connected. WHY would you install a new one? Why not just install the old one?
2. They are sealed systems. IF you had a leaker, then ALL the coolant would have been gone by now. They only hold a 16 ozs of coolant.
3. Water Coming OFF the roof indicates the Unit is doing its job.
4. Your brother and you have no way to tell if the compressor is "going" bad:B FYI, your compressor is not going bad.
5. How hot is it and how big is your RV? Doug

OP here,

The end of the sensor did not have the flat blade attached so it broke off or whatever. To be safe it wasn't an expensive part so I replaced it.

I stated that I had no clue about the compressor. Was hoping for a little feedback if there was any simple way to determine any issue with it.

It was in the mid 70's now 80 at noon and the AC has not shut off at all.

It is a 32 foot 5th wheel and the AC is a 15,000 BTU unit.

A 15k AC in a 32 foot RV will NOT cool the RV. Especially if you have slide out/s. Period. The max size for a ducted 15k is about 27 feet. Don't listen to responders that state they have a over 27 foot that does cool with 1 AC. I am giving you 40 years experience with RV's and sizing of Roof AC units. You need to have a operational check of that AC unit. You need
1. The compressor amp draw at ambient correct temp
2. The Temp Differential between the closest cold air outlet and the return air filter. The temp Diff will be 19 to 22 degrees. IE -- 82 hot in 62 cold out would be very good. Doug

[belairbrian]

Two solid pieces of advice already posted.
1) check the differential temp - That should tell you if the compressor is working properly.
Run A/C fan on high- At one time Dometic had a service bulletin about running with low fan causing evaporator coil icing in high humidity.

Make sure the fan switch is in Auto. If the fan is in ON, it will seem like the system is running all the time.

[dpgllg]

dougrainer wrote:
1. The freeze Sensor not connected. WHY would you install a new one? Why not just install the old one?
2. They are sealed systems. IF you had a leaker, then ALL the coolant would have been gone by now. They only hold a 16 ozs of coolant.
3. Water Coming OFF the roof indicates the Unit is doing its job.
4. Your brother and you have no way to tell if the compressor is "going" bad:B FYI, your compressor is not going bad.
5. How hot is it and how big is your RV? Doug

OP here,

The end of the sensor did not have the flat blade attached so it broke off or whatever. To be safe it wasn't an expensive part so I replaced it.

I stated that I had no clue about the compressor. Was hoping for a little feedback if there was any simple way to determine any issue with it.

It was in the mid 70's now 80 at noon and the AC has not shut off at all.

It is a 32 foot 5th wheel and the AC is a 15,000 BTU unit.

[dougrainer]

1. The freeze Sensor not connected. WHY would you install a new one? Why not just install the old one?
2. They are sealed systems. IF you had a leaker, then ALL the coolant would have been gone by now. They only hold a 16 ozs of coolant.
3. Water Coming OFF the roof indicates the Unit is doing its job.
4. Your brother and you have no way to tell if the compressor is "going" bad:B FYI, your compressor is not going bad.
5. How hot is it and how big is your RV? Doug

[garym114]

Run it on hi speed fan.

[beemerphile1]

Put a thermometer in the return air and note the temperature. Then put the thermometer in the discharge air flow and note the temperature. What is the difference? If the discharge is 18 or more degrees colder, everything is good.