More A/C problems!!!

[susanandlance]

PS HI code, 2007 36 Sedan Bridge, excellent water flow out both hull ports, cleaned strainer AGAIN, no help. And this is after technician reported 55 degrees laser gun from vents, uhhhh hello, 94 degrees in cabin today. Not too happy about this trouble child now.

 

[bahamabreisus]

You need to flush the AC lines. They are scummed up, so heat won't transfer.

 

[CaptRonn]

You need to flush the AC lines. They are scummed up, so heat won't transfer.

Yep. I have a fitting that I attach to the line off of the AC water pump, place it on the line (once removed from the pump) and attach the hose from the city water on the dock. Turn on water spicket full volume and blast out the crud. It’s amazing to see what come out. Reattach the line, do the other ac line the same. I go this a couple of times during summer months.

 

[susanandlance]

You need to flush the AC lines. They are scummed up, so heat won't tra.

Will do thanks!!

 

[susanandlance]

Yep. I have a fitting that I attach to the line off of the AC water pump, place it on the line (once removed from the pump) and attach the hose from the city water on the dock. Turn on water spicket full volume and blast out the crud. It’s amazing to see what come out. Reattach the line, do the other ac line the same. I go this a couple of times during summer months.

Will do thanks Ronn!!

 

[bbwhitejr]

If that doesn’t do it, let me know and I will tell you about my experience and the HP switch.....

Bennett

 

[susanandlance]

If that doesn’t do it, let me know and I will tell you about my experience and the HP switch.....

Bennett

Thanks Bennett, I definitely will!!

 

[susanandlance]

If that doesn’t do it, let me know and I will tell you about my experience and the HP switch.....

Bennett

Let me know now pls sir, I've had many issues on late model Chevrolet trucks with that switch. TIA brother

 

[bbwhitejr]

I was having issues with mine shutting down on Hi PS also. Sometimes the compressor would not come on. Sometimes the thing ran perfect.

Called Dometic after emailing them and the tech told me to check for loose connections on the 2-yellow wires that go to the Hi Pressure switch. If that was not it, he said the switch itself may be flaky. The yellow wires felt good and tight, but I pulled them off of the spade connectors anyway and pushed them back on.

She has never missed another beat. Here is s pic oh the Hi Press switch. My unit is a newer STX16, but should be similar.

 

[liv2ryde100]

We throw a chlorine tablet in the ac sea strainer a couple times a season. Seems to keep the lines nice and clean

 

[susanandlance]

I was having issues with mine shutting down on Hi PS also. Sometimes the compressor would not come on. Sometimes the thing ran perfect.

Called Dometic after emailing them and the tech told me to check for loose connections on the 2-yellow wires that go to the Hi Pressure switch. If that was not it, he said the switch itself may be flaky. The yellow wires felt good and tight, but I pulled them off of the spade connectors anyway and pushed them back on.

She has never missed another beat. Here is s pic oh the Hi Press switch. My unit is a newer STX16, but should be similar.

View attachment 71657

Thanks buddy, I will try that as well whats strange is the tech just serviced it and what cooling great less than 2 weeks ago, he only serviced the salon unit, now neither unit cools...…...

 

[CaptRonn]

Thanks buddy, I will try that as well whats strange is the tech just serviced it and what cooling great less than 2 weeks ago, he only serviced the salon unit, now neither unit cools...…...

Which would be indicative of the lines needing to be blown out.

We are in hot weather now, and depending on location marine growth (algae) would be really accelerating, especially if your lines weren't completely clean.

 

[susanandlance]

Which would be indicative of the lines needing to be blown out.

We are in hot weather now, and depending on location marine growth (algae) would be really accelerating, especially if your lines weren't completely clean.

For sure CaptRonn!!!

 

[susanandlance]

We throw a chlorine tablet in the ac sea strainer a couple times a season. Seems to keep the lines nice and clean

Isn't chlorine hard on the brass tubing??

 

[liv2ryde100]

I have no idea, couple people boating their whole lives taught us the trick. That’s all I can say

 

[susanandlance]

I will give it a try after I flush the lines and use the sea strainer kit to back flush the system with barnacle buster

 

[fwebster]

Chlorine will eventually destroy the plastic parts in the cooling system. First to go will be the bottom of the strainer basket. This happens because the a/c will shut down when the temperature setting is reached and you are left with a super concentrated chlorine solution in the strainer. If you want to throw $75-$100 at the strainer every time this happens, then go for it.

Also, putting chlorine in the system after flushing with a barnacle buster may give you a chemical reaction you aren't expecting. If you are going to use chlorine tablets, then make a slurry of baking soda and water and run it thru the system to neutralize the acid before adding chlorine.

 

[susanandlance]

Chlorine will eventually destroy the plastic parts in the cooling system. First to go will be the bottom of the strainer basket. This happens because the a/c will shut down when the temperature setting is reached and you are left with a super concentrated chlorine solution in the strainer. If you want to throw $75-$100 at the strainer every time this happens, then go for it.

Also, putting chlorine in the system after flushing with a barnacle buster may give you a chemical reaction you aren't expecting. If you are going to use chlorine tablets, then make a slurry of baking soda and water and run it thru the system to neutralize the acid before adding chlorine.

Frank, So you don't recommend the tablets, just use barnacle buster??

 

[susanandlance]

Another thing I noticed was even though good water flow exiting hull ports water was warm. Is that normal??

 

[fwebster]

The a/c cooling water may feel slightly warm and that is normal with the compressor running.......hotter than just warm means your system isn't cooling adequately.

I bought the chlorine lesson the hard way. The tablets work, but the parts repair/replacement cost is too high.

As far as barnacle buster is concerned, I don't know what is in it and since the most commonly available acid is muriatic I suspect it is a mix of several acids. I do know that some acids will erode solder joints so I only use phosphoric acid which will not erode solder. The A/C coils are help together with solder as are heat exchangers so I don't risk damage to the A/C units and use something I know is safe.........Kleen -Strip makes a product called Prep-N-Etch that is sold in the paint departments at Lowes and Home Depot for about $17/gal. It is a 20% solution of phosphoric acid and I can descale both of my A/C units with 1 gal of Prep-N-Etch fed in thru the a/c flush valve. It takes about 15 minutes and I do it about every 18 months and my boat is used 12 months a year and my strainer basket is about 10 years old an in perfect condition.