Originally Posted by JohnEasley
Getting ready to flush the a/c system on our new-to-us boat
for the first time. It has three units that are supplied by a single
pump and strainer. Seems like it would be easy to
- Premix Barnacle Buster
- Close the through-hull
- Open the strainer and remove and clean the backet
- Have my wife turn the a/c on
- ...while I pour the Barnacle Buster directly into the strainer
- Turn off the a/c and let it sit for a few minutes.
- Put the strainer back in, close it up, open the through-hull
- And let it all flush out.
Seems like I've seen a video on this or seen someone do it... but my memory is faulty.
Okay, stop laughing and please tell me why this approach wouldn't work. What's the easy way?
To "clean out" your systems, you'll want to counter flow fresh water
through them, individually. Normally that requires introducing fresh water
at the discharge side and directing the counter-flow into a bucket or overboard
on the input side which normally requires the input side line between the raw water pump
and the unit be disconnected unless one has a "flush cap" that one can temporarily install one the raw water
strainer (see the TRAC Ecological web-site or TRAC Raw Water Filter Flush Caps
for information on the flush caps) although whether this approach would be effective in your case, with a manifold of some type directing raw water
to three different A/C units, is questionable. N'any case, once the flushing
water through the unit(s) runs clear, you'll want to counter-flow a Barnacle Buster solution through each unit for at least 60 minutes (although longer is better). For most raw water applications, TRAC Ecological recommends a 4:1 solution of fresh water/Barnacle Buster. In most cases, a typical marine
A/C unit needs about 1 to 1-1/2 gallons of solution depending upon the length of the feed line between the raw water pump
and the A/C unit. You can mix the solution in a bucket into which you place a small submersible bilge pump
attached to a hose that's connected to the discharge side of the A/C unit's heat exchanger
. The input side of the raw water circuit is connected to a hose that leads back to the bucket. Connect the bilge pump
to a power source and let it run for 60-120 minutes, recirculating the solution. Then, direct the discharge to a second bucket or perhaps a sink drain while introducing fresh water to the first bucket until the Barnacle Buster solution has been completely replaced with fresh water. With that your system will be well cleaned out any ready for another year or so of service
Having 3 units connected to a single pump will make the foregoing somewhat problematic unless you have vales that allow you to close off the feed water to any single unit.