Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 02-02-2007, 08:22   #1
Registered User

Join Date: Sep 2006
Posts: 51
Flushing AC coils

I would like to hear from those that like me live in warm water areas where water conditions lend to fouling in the exchange coils of their marine AC systems. I know of people in my area that 2-3 times a summer run freshwater thru the system to flush sedement and "crud" from the system. I found some information on the web that suggests a 5% muratic acid flush to and clean the coils. What type of fittings or adapter is suggested? Should this be treated in the same manner that winterizing is done? I hope this post is some help to all.

stuffinbox is offline   Reply With Quote
Old 02-02-2007, 13:39   #2

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,742
I'd check with the makers to find out what your coils are made from, and what's compatible with it, so you clean the coils without eating away metal.

hellosailor is offline   Reply With Quote
Old 02-02-2007, 13:55   #3
Registered User

Join Date: Apr 2006
Location: presently gallivanting back across the Pacific... Pago Pago at the moment
Boat: Hylas 49 - GALLIVANTER
Posts: 201
I'm certainly no expert, but...

I use a vinegar.

Whenever the a/c performance starts to suffer...

Turn off the a/c unit at the breaker, disconnect inlet & discharge hoses, place a spare a/c circulation pump in a bucket, run a hose from the pump to the inlet and another hose from the outlet and back into the bucket. Secure the loose end of the return hose!

Pour a gallon of vinegar into the bucket, add enough hot water to submerge pump, turn pump on and circulate vinegar for 15 ~ 30 minutes.

Reverse order upon completion.

OR - pay the a/c guys $150 to come and do the same procedure.

For some reason - the fridge condenser rarely needs cleaning.

Stay cool,

Gallivanters is offline   Reply With Quote
Old 02-02-2007, 18:29   #4
Moderator Emeritus
Pblais's Avatar

Join Date: Mar 2003
Location: Hayes, VA
Boat: Gozzard 36
Posts: 8,700
Images: 15
Send a message via Skype™ to Pblais
I use a vinegar.
Sounds like a better route. This year we had jelly fish so thick you could walk across the water. Did a lot of back flushing in both directions with a hose and city water connection. My problem was at the through hull not the coils. You really don't need to be using anything stronger than vinegar.

Muratic acid might be better for engine heat exchangers but not for light weight A/C coils. You need to be gentle on the chemicals.
Paul Blais
s/v Bright Eyes Gozzard 36
37 15.7 N 76 28.9 W
Pblais is offline   Reply With Quote
Old 03-02-2007, 02:48   #5
Moderator Emeritus
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 32,216
Images: 240
Kirk (Gallivanters) describes the generally accepted method of cleaning Condensers & Heat Exchangers.
I might add that a “spare AC pump” isn’t necessary. Since most Air-Conditioners need on the order of 200GPM of cooling water per Ton (12,000BTUH) of capacity, a cheap bilge pump (500GPH) could do the job.

Marine air conditioner raw water systems are typically manufactured from copper alloys, and lead/tin or silver solder. These materials are not generally harmed by proper cleaning with appropriate strength acid/water solutions, for limited amounts of time. Many Marine Air-Condittioner manufacturers sell cleaning solutions which are appropriate for their particular systems, and provide recommendations for using their cleaning agents, which are often acid/water solutions. If you have concerns about proceeding on your own, I suggest contacting the system manufacturer for guidance regarding your particular model air-conditioner.

* I believe that Cruise-Air (Dometic) recommends a 5% Muriatic or Hydrochloric acid/water cleaning solution, followed by a freshwater flush.

If the Heat Exchanger contains Aluminum, it would likely be severely damaged by using ANY kind of acid-based cleaning solution.
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"

GordMay is offline   Reply With Quote

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Need Manual Troubleshooting Norcold SCQT-6406 works AC volt not DC volts ? chuck711 Plumbing Systems and Fixtures 6 03-11-2013 10:30
Reverse Polarity (AC) GordMay Electrical: Batteries, Generators & Solar 13 30-06-2013 12:12
Grounding Inverters & Chargers GordMay Electrical: Batteries, Generators & Solar 11 13-03-2011 17:50
AC Electrical Refit knottybuoyz Construction, Maintenance & Refit 15 10-11-2006 19:52
AC charger smarter than the 3 stage "smart" charger? CSY Man Electrical: Batteries, Generators & Solar 64 30-09-2006 12:49

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 01:10.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.