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98 Model 405 A/C Issue

Posted: February 17th, 2020, 8:21 pm
by Serendipity
Captains,

So this past summer I took a 2 week vacation by plane to the Bahamas. When I returned the aft cabin a/c was not cooling and the pump was not pumping from the thru hull.

The bow a/c was and is cooling properly and was pumping correctly even though this is a one strainer pump system? I had cleaned the strainers before I left but I am on a Lake and normally this is never an issue. Just time I guess gents?

So my questions are these? Local boat mechanic feels the compressor has gone bad?Supposedly he tried to charge the unit to no avail?
Is there a reset switch?
Both thru hulls are pumping fine after I cleaned them throughly.
Aft A/C will blow but nothing cool or hot?
Would you replace the compressor or the whole unit?
Compressor is R22 and $500 to replace just it part only.
New unit is 4 to 5 times this amount as you know.

What would you advise me to check or your opinions please? :help:

Thank you Gents

Re: 98 Model 405 A/C Issue

Posted: February 17th, 2020, 9:46 pm
by g36
Imo if its the original to the boat I would not spend money replacing the compressor only. I would bite the bullet and replace the whole unit. I've had to replace 2 of the 3 on my 97 405 since I've owned it. 22 yrs is pretty good for a hvac unit on land or boat.

Re: 98 Model 405 A/C Issue

Posted: February 17th, 2020, 9:55 pm
by tomschauer
OK, a couple thoughts here. I don't leave our units on when we aren't on the boat because they will only run xxxx amount of hours until their life ends, and I want those hours to be while we are on the boat. Also, if a line fails, your are pumping more water into the bilge tan maybe your bilge pumps can remove. Both of these personal preference.
Your 1998 vintage SHOULD be automatic reset pressure switches. If you had a clog in the water flow, the compressor most likely tried to start every few minutes for days or weeks. This will damage the compressor start windings. And significantly shorten compressor life. The mechanic said he tried to charge the unit? Was the compressor running? if not, he was wasting your time and your money and he doesn't know refrigeration. You should not have to pay for any r-22, as it was most likely not used?
At this point you have a couple choices, find someone that knows ac, have them check the thermal overload and start capacitor. If it is one of those you may get off semi easy. But, most likely cost at least $200 for the service call. If the 20+ year old compressor is bad, I would replace the complete unit. If the existing compressor did have an electrical failure, you now have acid in the system and it will take out the new compressor in a couple years unless swapped out properly with acid filters changed regularly, which would cost more than a new unit when all said and done.

Re: 98 Model 405 A/C Issue

Posted: February 17th, 2020, 10:33 pm
by Serendipity
I agree and feel like replacing the unit is the best route for me to go as well.

Do you have a recommendation on a unit for a 98 405 model?
I am in the south and I find the boat was a little warmer in the summer than I preferred. It also only has 2 units and not 3.
So it appears this unit is a 13500 unit? Would you go back with a 16000 unit and where did they install the 3rd unit?
Seems to me upgrading to a 16000 unit would be a better option, then upgrading the other bow unit when it goes bad.
Wiring a 3rd unit in doesn't sound like much fun. Lol but I am curious where it would be placed?

Your thoughts and the brand preferred please?

Re: 98 Model 405 A/C Issue

Posted: February 18th, 2020, 7:15 am
by g36
I'm in Tennessee not sure if your south of me. I don't leave mine running when not aboard but in the summer we pretty much live aboard during the week and weekends. I have 1 ac unit in aft cabin , 1 unit in salon and a unit in fwd cabin but also ducted blowing into salon over microwave. I installed the aft cabin one myself because I didn't get enough cooling back there with only 2 on the boat. You probably will already have 3 ac breakers in your electrical panel for ac on shore #2. You'll get plenty of suggestions for hvac units .as far as replacement I chose mermaid manufacturing for 5yr warranty and no specialized thermostat or electronic components that were only unique to the unit. Meaning repair parts are available anywhere . I have had them on my trojan before my Carver and been very happy. I would up the unit to 16000 no matter what you do.

Re: 98 Model 405 A/C Issue

Posted: February 18th, 2020, 3:59 pm
by km1125
You need to find documentation on your current unit. There are some that have 'lockout' sensors that have to be manually reset if you get too high a pressure or temperature.

Someone could also apply voltage directly to the compressor (with a start capacitor wired in) to see if the compressor runs at all. All you need is just a couple seconds to know if it will run or not.

Re: 98 Model 405 A/C Issue

Posted: February 18th, 2020, 5:08 pm
by Serendipity
Where would the 3rd unit go? Under the aft cabin bed?

I have a unit behind the couch in the salon which feeds the aft cabin and dinnette.
Then I have a unit underneath the front bed that I have retaped the duct work.

Seems like to me there should have been a 3rd unit in the aft cabin?

Did all 405's come with 3 units or just 2?

Seems to me the aft cabin bed or closet is really the only other place to install a 3rd unit.

Your thoughts please and I take for granted my 10k generator will support it as it hardly has a load running the 2 units.

Re: 98 Model 405 A/C Issue

Posted: February 18th, 2020, 6:01 pm
by g36
I know the Kohler 10e genset which you probably have also will have no trouble at all running the 3 ac units. I am the 2nd owner of my 405 the original owner ordered it with options he wanted so I think the 3rd was a option not a standard install. But I bet all came with 3 breakers in the electrical panel whether all installed or not. I do know the OEM position in the aft cabin is under the bed. I can tell you having your own ac in the aft cabin with it's own thermostat will make a huge difference in sleeping and temp management of the aft cabin. Btw We don't go to sleep with genset running just to clarify .

Re: 98 Model 405 A/C Issue

Posted: February 18th, 2020, 11:21 pm
by Serendipity
Yes it is a 10E Kohler Generator and I just wish the boat had come with a 3rd unit, but oh well.
Yes running the generator and sleeping is always a major no no on a vessel so small.

I do plan on keeping it a while so I will update it over time.
Thanks for everyone's advice

Re: 98 Model 405 A/C Issue

Posted: February 19th, 2020, 7:11 am
by Midnightsun
Serendipity wrote:Source of the post Where would the 3rd unit go? Under the aft cabin bed?

I have a unit behind the couch in the salon which feeds the aft cabin and dinnette.
Then I have a unit underneath the front bed that I have retaped the duct work.

Seems like to me there should have been a 3rd unit in the aft cabin?

Did all 405's come with 3 units or just 2?

Seems to me the aft cabin bed or closet is really the only other place to install a 3rd unit.

Your thoughts please and I take for granted my 10k generator will support it as it hardly has a load running the 2 units.


I have only a 9kw genset which runs all 3 AC (12, 16 and 7000 btu) units and then some without issues. Yes Carver located the aft cabin unit under the bed on my model which is ducted to do the aft head as well as the master state room.