Watermaker Throughhull

[rubberduck]

When i installed my watermaker in the spring i used an existing through hull that was originally installed for a saltwater footpump. This is a flat type of through hull that are standard in most applications.

I have noticed that if i run the watermaker underway that air is getting in the system and causing the pressure to drop. I can normally run the system for 5 to 15 minutes before i have to turn it off.

I'm wondering if installing a scope type through hull like the kind you see on on the engine seawater inlet would help this issue?

Anyone with experience with this?

Thanks

[NPCampbell]

This is a hack but a degassing valve may work. I'm not sure of a water makers typical configuration. If the water maker's pumps prime via siphon then the degassing valve is normally open so it won't work. However, if there is a place to install a tee between a pump that tolerates air in the line and the water maker then a degassing valve setup might work until you can install a new thru-hull.

[stormalong]

Had the same problem with my water maker install. It is amazing how much air is in rough water.

The answer is to locate an intake as low as possible in the hull. In my boat the fin keel goes down a long way. I put the through hull as far down as I could reach to turn the seacock. That solved the problem.

[Tellie]

This is actually important to deal with. Most watermakers don't like air ingress and many with hp plunger pumps can be damaged. A forward facing scoop will certainly help but the location is important, the deeper the better. Or you may just have to slow down that hot rod while you make water.

[Q Xopa]

Originally Posted by stormalong

Had the same problem with my water maker install. It is amazing how much air is in rough water.

The answer is to locate an intake as low as possible in the hull. In my boat the fin keel goes down a long way. I put the through hull as far down as I could reach to turn the seacock. That solved the problem.

All sounds good.

A Sea Chest might be another option. Even if the thru hulls are sucking in some air, it will be at the top of the Sea Chest.

The Sea chest needs a vent in the top going above the water line so the Sea chest dosent fill up with air and displace the water.

Having your water maker intake coming from lower in the Sea chest.

I realise this is not practical for everyone room wise and other reasons.

Just a thought.

[Lepke]

I have a similar issue with my salt water pump getting some air. I solved it by installing an air eliminator (used in hydronic heating systems) in a loop in the line after the pump. One shown is $10 on eBay. They come in other sizes, shapes and styles to $100.