R25 Air Conditioning

C

commander bill

New member
Are any of you Ranger tug owners having this issus? When I picked up my boat the AC seawater pump would not self prime and we had to jog it several times to ever get it to pump. With no flow the AC unit trips on HFP (hi freon pressure) & no water flow was the logicval cause. After we finally got the pump primed the AC ran great. After a week in florida we hauled boat up here to Tennessee where I have it in a slip. First week or so it was wet & raining. We went out anyway. Tug kept us dry & warm. Now weather has shifted toward hot & I need AC. Again I can not get darned pump to prime. Pump is a 110 VAC magnetic pump located near engine. There is a relatively long run of hose up to AC location and it is possible there might be a loop seal in hose which is keeping pump air bound. Manual says to take discharge hose of of pump to allow water to flow into pump. This is not that easy to get to and still did not help.

My questions. Has anyone else experienced this problem and found an easy fix? And does anyone know if these magnetic pumps can run dry without damage?
 
Yup, I have always had that problem. It will not prime itself. I disconnect the water intake hose and use the wash down to pressure water into the system. I think if a person shuts off the through hull ball cock when you shut down the air it might just be ready for the next time. Pain in the butt. I wonder if a check valve would cure the problem?

captd
 
Your reply is very helpful. I was beginning to think I might have a kink in the hose in route to AC unit. However, if yours does this then mine is likely not kinked. One mod I want to do next winter, along with big GPS & radar is installing flushing connections on all 3 seawater lines. I think a flush after putting boat in water might cure this problem. I also wonder if the pump is damaged by running dry. I am assuming the pump will stay primed once it starts pumping - until next time boat is taken out of water.

By the way has there been a resolution on Mis Dee's problems. Your adventures this winter made me wish I was retired. I look forward to trailering boat down to St John river this winter for maybe 3 weeks if I can get away from work that long. Probably not much chance in that.
 
Well, I googled Dometic pumps and found several references to them. One provided installation references and said this pump must be installed at lease 2 feet below water line. That would be hard to do in the Ranger unless you were using it as a bilge pump. Another reference showed installation with a prime tank that stayed full and allowed pump to maintain prime.
 
Plumb in a "T" with a ball valve between the raw water wash down and the AC water intake. Open this valve, run the raw water pump (also with a "T") and prime the unit this way each time.
 
The way I fixed this problem was to install a loop in the hose between the pump and the a/c unit. At the top of the loop, I installed a 3-way valve.

In the "bleed" position, the pump was connected to a 3 foot piece of clear hose that I could suck water through the pump.

Once I see water, change valve to "run" to send water to the condenser.

An additional benefit of this set-up, is when the through-hull strainer clogs up, (eel grass, plastic bag, etc.), I just need to open the valve to "bleed" and blow through the hose to clear the blockage.
 
As a possible purchaser of a Ranger 25, it seems to me that doing all this stuff, sucking fuel, putting in loops, etc...reminds me of my teen years fooling with the engine of a 51 Ford...not what i would expect of a purchase well over 100 grand. Factory problem, right?
 
Dr. Bob's suggestion soundsz like best way to go only I did not order a wash down system. However, it looks easy to install and that is likely what I will do at end of season.

Yes I would say the AC seawater issue is a design deficiency. I am not sure what you mean by sucking fuel unless you are talking about a problem the Ranger 21's have with sucking air in fuel lines. I doubt the R25 with the 75 gallon tank located so low in the boat will ever have that issue.

The issue I have with the AC is minor compared to others I have heard about. Some people have not even ordered AC on their R25s. I will rate the boat a 9. However, Rangers ability to publish a manual rates a minus 5 and decreasing.
 
hi,

fairly common problem.......airlock occurs because the water running by the intake thruhull underway creates vacuum and sucks all the water out of the intake line.

easiest solution........turn your intake thruhull off before you leave the dock unless you are running the ac unit on generator power (it may airlock again depending on the speed you are running)

if it airlocks when you are not underway, then there is another problem......

we will be happy to give you all possible scenarios and solutions if you wish.

best regards,

keith turner
www.turnermarine.com
 
Ranger did not connect the cold air outlet on the AC unit to the louvered outlet that they installed. There is about a 1" air gap. This resulted in cold air being looped right back into the return air duct on the AC unit causing the cabin to be warm and the area under the AC seat nice and cool. You could see daylight by looking into the outlet louvers over to the inlet louvers. Not to mention that the AC outlet does not align properly with the outlet louver assembly.

Maybe marine AC is installed differently in Washington than in Florida.
I have a quick fix if your R-25 has the same problem.
 
Keith[/quote]fairly common problem.......airlock occurs because the water running by the intake thruhull underway creates vacuum and sucks all the water out of the intake line.

easiest solution........turn your intake thruhull off before you leave the dock unless you are running the ac unit on generator power (it may airlock again depending on the speed you are running)

if it airlocks when you are not underway, then there is another problem......

we will be happy to give you all possible scenarios and solutions if you wish.

best regards,

Keith,

We all wish for possible scenarios and solutions, Thanks in advance.
For my style of boating, having the gen set running as I leave the dock is not good enough for me . What else have you got?

I wish Andrew would jump into this thread right now and give us the remedy and what they are doing now for the new boats coming off the line.
captd
 
My original post which started this discussion was based on my problem related to pump not self priming when boat put back in water. Once you get the darn pump to prime it seems to works OK without shutting hull valve. I was cautioned by Mark to not attempt to run AC at higher speeds because of reason mentioned above. However, that is a spearate issue not related to my problem.

The AC seawater pump is designed to be installed lower below the waterline than is possible on the tug. Alot of air is trapped in the hose from the hull stop to the AC in the forward part of the cabin. I finally got the pump primed by removing the pump discharge hose at the pump & allowed water to flow through the pump out to bilge - then while still flowing I rapidly reinstalled hose on pump and started AC. Worked first attempt.

Once primed I have had no issue with the AC operating OK even after higher speeds with hull valve open. I plan to follow Dr Bob's suggestion & add a washdown system & flushing connection after I pull the boat at the end of the season to avoid the issue next year.
 
I have tried to duplicate this problem several times during my seatrials. The pump is as low as we can get it in the tug. One thing I have found to work very well if it wasn't getting primed was to fire the AC before releasing it off the trailer. By doing this the stern of the boat sets deeper in the water. In the past 20 boats I have tested I have tried to start the Air Conditioning at all different times of Seatrial and cannot get it to fail. What I suggest doing Bill is submitting some pictures of your installation to me @ (andrewcustis@rangertugs.com). Hope this helps.
 
My boat is hull # 67 so I would assume that is one of last 20 boats. Again my AC has not failed while cruising. It has just been very difficult to get it to self prime when first placed in the water. Marc had the problem in florida until they removed the pump discharge hose and flushed water through the pump. When I brought the boat home I had the same issue only my bad back made removing the hose harder. But I was not able to get the pump to self prime until I took off the hose.

I do not consider this to be a major issue because once the pump is primed the first time it stays primed until boat pulled from water. I am leaving it in the slip until the end of the season & doubt it will be a problem until then (It has not failed in the month since I finally got the primed). Then modification time will be with us. I think I can solve this issue with a flushing connection.
 
henrym":1r8c2qt0 said:
Ranger did not connect the cold air outlet on the AC unit to the louvered outlet that they installed. There is about a 1" air gap. This resulted in cold air being looped right back into the return air duct on the AC unit causing the cabin to be warm and the area under the AC seat nice and cool. You could see daylight by looking into the outlet louvers over to the inlet louvers. Not to mention that the AC outlet does not align properly with the outlet louver assembly.

Maybe marine AC is installed differently in Washington than in Florida.
I have a quick fix if your R-25 has the same problem.
Click to expand...

After reading your post I checked my Air Conditioner and sure enough, I have the same situation. So, what's the easiest way to line up the air duct and correct this problem? (thanks for the heads up!)
 
The easiest way to fix the problem is to purchase a roll of Gorilla Duct Tape. Gorilla Duct Tape is black in color, twice as heavy as regular duct tape, tenaciously sticks to just about any surface, and it does not deteriorate when it gets wet. Use the tape to connect and seal the AC outlet to the poorly aligned cold air outlet box. Then seal the air gap that will stop any cold air from being looped back to the inlet side of the AC unit. By doing this, you will just about double the cold airflow and the thermostat will then become more sensitive ambient temperature in the cabin.

After completing the job, throw away your old silver faced duct tape as Gorilla Duct Tape will become one of your best friends. When the hurricanes come, I use it to seal the bottom of the outside doors and two weeks later it removes with the sticky stuff staying on the tape.
Henry
 
Thanks for the tip. While at the boat this weekend I sealed the connection between the air conditioner fan output and the diffuser grill with gorilla tape as you suggested. A better solution would be to have a diffuser grill that fits the fan output better. The shape of the fan output just doesn't fit into the duffuser grill they selected. It would not be easy to fix now, but should have been easy to do when first installed.

I also thought I had a 16,000 BTU AC unit but discovered that it's only 10k or 12k based upon the dimensions. I can't see a rating label. Does anyone know what size AC units are installed on the R 25? Maybe mine's an early model with a smaller unit?
 
I was told by Ranger that my Tug (#85) had 16,000 BTU AC. I'm thinking of enlarging the AC access hole under the seat for future potential servicing etc.

I keep my boat on a lift. I lowered it to the point that the AC raw water sea cock is just under the water by a few inches, then take a water hose and inject water into the rear AC condenser discharge outlet until there are no more air bubbles coming out of the sea cock. Close the sea cock and only open it when the boat is in the water and you want to use the AC. (The injected fresh water will pass right through the magnetically coupled centrifugal AC raw water pump with ease.)
Henry
 
I don't know what the deal is with my air conditioner, but I have not had any sort of problem with it getting an "air lock" and not pumping water.
My boat lives on the trailer when we are not using it and I have not had to close the sea cock to keep it primed - works without a hitch so far, maybe they have done something different on the new hulls, mine is #89.

However I did have some trouble with my generater this last weekend. When I started it I looked to see if water was exiting the exhaust and there seemed to be a little less water than I remembered, but still a "spray" of water was exiting the exhaust, within about 2 minutes the temperature sensor shut it down. I checked the generater strainer and it was clean also had excellent water flow thru sea cock, tonight I will look at the impeller and see if something is messed up with it, does anybody else have any other suggestions?

I started the generater the next day just to see if it was ok and it ran fine, so I turned it off after about 20 seconds - still not very much water thru exhaust & generater didn't seem hot...

John
 
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