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Kraden313 · 12-07-2012, 07:22

Hunter 410 sailboat.

What is the safest chemical to run through the A/C unit to clean it out? We currently live on board on the Trent river. The river this time of year is nasty, trashy, and becomes stagnant. Are raw water strainer seems like its working double time to filter the trash out, however, we seem to be having A/C problems particularly with the flow of water coming out of the boat. About a month ago the flow was solid and strong and now it's beginning to trickle out of the boat. Just need some advice on what chemical to run through the A/c unit.

Captain Bill · 12-07-2012, 07:41

One of the best things you can do is turn the system off for a couple of days, of course this time of year that's not what wants to do. Once the stuff in the pipe dries out it will flush out fairly easily. I've found that putting a bromine tablet in the strainer helps a lot. They are available from any place that sells hot tub supplies. They don't do much after the system is clogged though. Chlorine is generally safe if not allowed to sit in the hoses too long and will kill most of the growth rather quickly. Some types of hose is perfectly safe to let chlorine sit in, but since I don't know what kind of hose you have I hesitate to recommend letting it sit in the hose too long.

Kraden313 · 12-07-2012, 08:57

Thanks for the reply. We do use chlorine tablets in the strainer all the time however the nasty water eats them up quickly. We do believe there is junk in the lines now which is significantly slowing down the flow to the outside of the boat. We have been told by several other boaters it is safe to run muriatic acid through the a/c to clear out the junk. What are your thoughts on that???

jacob30 · 12-07-2012, 09:19

I would say your best bet is white vinegar. Let the pump suck in about a gallon and then turn it off right away and shut the valve so it sits in the lines overnight or as long as you can leave it.

jacob30 · 12-07-2012, 09:29

I have worked with muriatic acid quite a bit to clean pumps and things. The key is always add acid to water NEVER water to acid. It will create a violent reaction if you add water to acid With that said I would use a ratio of 1:20 acid to water. The mixture is quite dangerous so mix outside as the combination produces gases when mixed. Once mixed use the 1:20 mix as you would the vinegar. Have baking soda nearby to deal with any spills. USE Gloves and goggles too!

Muriatic acid works quicker and better but essentially does the same thing as vinegar but much quicker.

Quote:

Originally Posted by Kraden313

Thanks for the reply. We do use chlorine tablets in the strainer all the time however the nasty water eats them up quickly. We do believe there is junk in the lines now which is significantly slowing down the flow to the outside of the boat. We have been told by several other boaters it is safe to run muriatic acid through the a/c to clear out the junk. What are your thoughts on that???

sdowney717 · 12-07-2012, 11:15

I simply bought some muriatic pool acid from HD at 30%
Diluted to 10 to 15%
Disconnected lines at pump and discharge
Used 2 funnels secured ends into hoses and secured to something so they dont fall and poured in the acid.
Let it sit for 5 minutes.
drained it out
Then flushed with a hose. should keep a hose at the ready if your using acid.

It looked clean on the inside of the water condenser pipe connection and I got a small amount of brown green scum came up in the funnel. You know it has filled the pipe when poured into one side it comes out the other with the hose ends above the tubing coil.
It only takes maybe a qt of acid water mix to fill the pipe.

I am clumsy and spilled the acid-water mix on my shorts which the hose easily flushed off with no effects.

Websites will say recirculate a 5% solution for a while till clean. I do have a rubber impeller pump and I suppose could use bucket. I kept imagining though the pump leaking acid or it spraying acid on me with the pump. How do they know when it is clean?

chrisjs · 12-07-2012, 12:32

I'll bet your shorts will develop holes next time they are washed!! Been there - done that!!

Kraden313 · 12-07-2012, 18:49

Wow! Thanks for the very informative responses. Much appreciated. All very good information no doubt.

Travlin-Easy · 12-07-2012, 19:21

Did you try back-flushing the system? Sure cleaned a lot of Susquehanna mud out of my system, most of which had caked around the intake strainer on the hull.

Good Luck,

Gary

Kraden313 · 14-07-2012, 10:38

We have not tried that yet but that might possibly be an option as well. We are somewhat new to all of this and learning so much. So all this information is really good and very helpful. Thanks so much.

Scott Berg · 23-07-2012, 15:24

We have a system that works VERY well on all the boats we service on the upper Potomac River that is filled with silt. Take some T fittings, valves and an air hose jack. Garden hose connects to a valve, valve to the T, and there other side of the T to a hose that can connect to the condenser "water in." The middle of the T has a valve and a 1/4" air jack. Garden hose to one end, air hose from compressor to the middle, AC unit's condenser on the other end. Turn on the water and watch mud come out (a bit). Then open the air hose and watch the bubbles and turbulence blow out much more. We do this maybe twice a season and all our customers have working air-conditioning. While the acid rinses do work on scale on silt and mud it's hard to beat what we call "scrubbing bubbles." I can post some pix of the unit that we call and AIS or Air Injection System if people are interested

Scott