Anyone having issues with water being too hot for your A/C to run?

[sailorboy1]

You didn't answer my flow question

WHY did the manufacturer say a high flow would shutdown your system

[MarinAirNoWorky]

They didn't say why. They didn't answer the question.

[AKA-None]

High pressure maybe
Higher volume pump into the same size plumbing will end up at a higher pressure
Just a thought

[Bowdrie]

As with so many modern devices/contraptions, the ongoing goal of engineering is to reduce size/weight, (and cost,) to the lowest possible number.
Your unit, (with 90F water,) is probably trying to operate in what a pilot might call the "coffin corner", where no matter the increase in the pressure/flow of the water there just isn't enough surface area in the condenser to take advantage of the pressure/flow.
As with refrigeration, AC units do better with BIG condensers.
We could have another score of pages of responces but none will improve anything if the condenser is just too d**n small for the operating parameters.
Your unit probably incorporates a condenser similar to these.
https://refresearch.com/product/cond...ooled-coaxial/

[MarinAirNoWorky]

Well guess what... using their recommended pump...did NOT solve the problem... as some of us had surmised.

Oh well. Will respond to them asking what is next (I know I have to buy a different AC I guess from a different brand, as many other AC's are running just fine... but are older and out dated technology wise)...

Will let you know what they say now..


( this is the pump I am using now: https://www.marinaire.com/pump-p/mfp300kt.htm , it was a real ball buster installing this in a 98 degree cabin)

and this is the unit

https://www.marinaire.com/Marine-air...-p/msba6k2.htm

From the manual:
http://marinaire.com/v/marinaire/Dow...tionmanual.pdf



So there is NO way the water is 95.

The cleaning procedure that has been done on this unit:

1. Barnacle buster put into the system and let sit for 30 mins, then rinsed out.

2. Same thing used (40 dollars a gallon!) and circulated through for an hour or more.

3. An AC guy came out and used this stuff for an hour...

Same result. When the water says 90 degrees or more on the chart plotter it throws an E4 error for high pressure too high.

The other thing was all the cleaners... they came out looking just as good as they went in. No real signs of anything bad.

What else can this be? I'm buying some gauges on amazon right now.

Also attached a screen shot from their E4 error troubleshooting guide about what waterflow to use.

[MarinAirNoWorky]

Originally Posted by Bowdrie

As with so many modern devices/contraptions, the ongoing goal of engineering is to reduce size/weight, (and cost,) to the lowest possible number.
Your unit, (with 90F water,) is probably trying to operate in what a pilot might call the "coffin corner", where no matter the increase in the pressure/flow of the water there just isn't enough surface area in the condenser to take advantage of the pressure/flow.
As with refrigeration, AC units do better with BIG condensers.
We could have another score of pages of responces but none will improve anything if the condenser is just too d**n small for the operating parameters.
Your unit probably incorporates a condenser similar to these.
https://refresearch.com/product/cond...ooled-coaxial/

YUP. I'm sure you are right, but if a company says 95 degree water inlet... (and the inlet is 2 or so feet down into the water)... it should actually work!

[maury]

I find after a few minutes or an hour a simple reset and ac will start working again and sometimes stays on. Seems like max temp is an intermittent issue on hot days affected by how quickly the current is bringing cooler water.

[Chotu]

I think it’s pretty clear at this point that the air conditioner you are working on does not have the ability to work in the current water temperatures that you are in. That’s all there is to it.

There is nothing else left to figure out or fix.

The only thing left would be to change the condense to a better one (company should own up to this and do it) or get some gauges on the system and see why you’re getting a high pressure Error.

Error cause is that maybe the system is actually developing over pressure OR maybe your sensor is bad.

The company will know this from experience working on their own systems.

Someone from the company itself needs to fix this because it was either poor engineering, poor supply chain with a bad sensor or just maybe it’s overfilled and has high pressure in general.

Either way, it’s out of the scope of the end user

[MarinAirNoWorky]

Originally Posted by Chotu

I think it’s pretty clear at this point that the air conditioner you are working on does not have the ability to work in the current water temperatures that you are in. That’s all there is to it.

There is nothing else left to figure out or fix.

The only thing left would be to change the condense to a better one (company should own up to this and do it) or get some gauges on the system and see why you’re getting a high pressure Error.

Error cause is that maybe the system is actually developing over pressure OR maybe your sensor is bad.

The company will know this from experience working on their own systems.

Someone from the company itself needs to fix this because it was either poor engineering, poor supply chain with a bad sensor or just maybe it’s overfilled and has high pressure in general.

Either way, it’s out of the scope of the end user

Yup. I sent a reply email to the company tech yesterday. Haven't heard back yet.

If the manual states 95 is the max and that really is the max, I can't imagine the inlet temp is 95, I guess anything is possible.

The point is the thing is just about 3 years old, so there's no warranty. I will be fixing this one way or another though. Just about at the limit to where I go to a neighboring boat that has had it running the entire time, find out what brand and model and just buy one of those.

[Chotu]

Originally Posted by MarinAirNoWorky

Yup. I sent a reply email to the company tech yesterday. Haven't heard back yet.

If the manual states 95 is the max and that really is the max, I can't imagine the inlet temp is 95, I guess anything is possible.

The point is the thing is just about 3 years old, so there's no warranty. I will be fixing this one way or another though. Just about at the limit to where I go to a neighboring boat that has had it running the entire time, find out what brand and model and just buy one of those.

I see. That’s bad news.

Sometimes buying the new one is actually the cheaper way, depending what your time is worth to you.

Maybe some people on here can recommend ones they are happy with (in 95-100 degree water) and you can see a trend as well.

[MarinAirNoWorky]

Just got off the phone w/ the company. They said that a few other people in my area have called in with the same issue.

I asked if the larger models all have this safety limit. The answer was yes.

Guess I have to start talking to the folks at the marina that seem to have no issue like this and find the exact model they have.

I've already looked at mermaid and dometic. They both state that after 90 degree inlet temp it's not likely to work.

Might have a 3 year old Marin air unit up for sale.. just can't not have AC when it's this hot, both air and water.

Have already explored other alternatives. They do work, but aren't as nice.. gotta love this global warming stuff.

[Chotu]

You could always also just run it into the ground now that you know you can’t use it. You could find out where that sensor is and disconnect it. Or bridge the wires or put in a resistor and do whatever it is you have to to get the proper signal back to the control unit. Allowing it to run over pressure.

I know. It’s not the Safe way. Things might break/leak. But if you are on the boat and you need some air conditioning you could give it a shot. The worst you could do is destroy the thing and overload the compressor. lol

I wonder if the company would tell you the resistance needed.

Maybe you can say that you are checking the pressure sensor with your multimeter and need to know the resistance range for testing.

Then, you could provided the correct resistance at all times to the control unit and get the sensor out of the loop.

It would keep going at least. I don’t know what might fail after, but it would keep going.

It might even just work fine until the waters get to 105 degrees

[MarinAirNoWorky]

So the other option is to let some of the refrigerant out. I haven't wanted to mess with that because of the company being involved. At this point I guess that might be an an avenue to explore.

Def annoyed I spent most of my Sunday swapping a pump in the heat, knowing that it wasn't going to fix anything.

[Chotu]

Originally Posted by MarinAirNoWorky

So the other option is to let some of the refrigerant out. I haven't wanted to mess with that because of the company being involved. At this point I guess that might be an an avenue to explore.

Def annoyed I spent most of my Sunday swapping a pump in the heat, knowing that it wasn't going to fix anything.

I wouldn’t do that one. It’s really bad for the environment.

It’s illegal also. But that’s not my concern. It really is just terrible for the environment.

Also, if you let out the refrigerant, it will change the way the system operates. It will have less power and be able to do less cooling.

It’s quite possible they have a pressure limit that is set really low. As a huge safety margin to protect the compressor. you might as well first try to see if you can get it running at a slightly elevated pressure. Your water isn’t that much hotter than the water it would take to be running fine, so the pressure isn’t that much greater. Just a little.

A few degrees difference in water temperature might be just kicking the over pressure switch off, but still be OK for the compressor. You really have nothing to lose.

[sailorboy1]

Originally Posted by MarinAirNoWorky

If the manual states 95 is the max and that really is the max, I can't imagine the inlet temp is 95, I guess anything is possible.

The thing about that far as high head pressure goes is it going to matter what the air temp is. A 95 degree water may work with a 3 degree air temp differential, but not a 10 degree one.

With that said have you tried to get the system operating with a cooler air temp at start to reduce the heat transfer load on the system?