I plan to upgrade my plumbing to add pressurized and heated water! Who can help me choose a heater?

Aug 22, 2021
31
Catalina Yachts 30 Lake Huron
Hello all!
I've decided to upgrade the plumbing on my 1986 C30 Mk2. It came with just the hand-pump faucets. I've already ordered a hose connection for shore-water, an electric water pump, little pressure tank, galley/head faucets, and a hosed showerhead that connects to the head faucet in place of the aerator. The last big thing I need to decide on and purchase is a water heater. The screen shot photo attached shows what seems to be a pretty good deal on a new Kuuma 11811 from EBay. Does anyone have experience with this heater or at least one from the same manufacturer? It seems to me that this model must be very similar to OEM for boats that came with heated water, right? I haven't done any measuring yet and figured out exactly where it (this model or another) should be installed yet. Has anyone else done the same upgrade to your C30? Thanks in advance for sharing any lessons learned.
 

Attachments

Jul 6, 2013
221
Catalina 30TR, Atomic 4 2480 Milwaukee
I put one of these in My C-30 3 years ago. It works fine, but the box is just a little larger than the original. I had to grind the edge of the hatch to get it in.
 
  • Like
Likes: Mooseman
Aug 22, 2021
31
Catalina Yachts 30 Lake Huron
I put one of these in My C-30 3 years ago. It works fine, but the box is just a little larger than the original. I had to grind the edge of the hatch to get it in.
Hi Jim, That's interesting, do you know if the model you installed was the Kuuma 11811, or was it a similar model? This model has these dimensions: 19.75″ D x 13.75″ W x 13.625″. Where in your boat did you put it? I think I saw a drawing that showed they are typically under the quarter berth somewhere?
Thanks,
Robert
 
Jul 6, 2013
221
Catalina 30TR, Atomic 4 2480 Milwaukee
Hi Jim, That's interesting, do you know if the model you installed was the Kuuma 11811, or was it a similar model? This model has these dimensions: 19.75″ D x 13.75″ W x 13.625″. Where in your boat did you put it? I think I saw a drawing that showed they are typically under the quarter berth somewhere?
Thanks,
Robert
I’m pretty sure that’s it. I’ll check the exact model number when I go to the marina later this week.
Catalina put the heater in the port lazerette. I thought it would be a drop in replacement, but I had to grind the opening about 1/4 inch larger. Once through the opening, it was a drop in.
 
  • Like
Likes: Mooseman
Aug 22, 2021
31
Catalina Yachts 30 Lake Huron
Robert you show Lake Huron. Which side of the border are you?
Hi Len,
I'm actually ended up renting a slip on Lake St. Clair (in Fair Haven, MI) for the rest of this season. Next spring I plan to venture up into Huron and maybe beyond if I can find the time. Have you spent some time on Huron?
 
Aug 22, 2021
31
Catalina Yachts 30 Lake Huron
I’m pretty sure that’s it. I’ll check the exact model number when I go to the marina later this week.
Catalina put the heater in the port lazerette. I thought it would be a drop in replacement, but I had to grind the opening about 1/4 inch larger. Once through the opening, it was a drop in.
Sweeet, thanks Jim!
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
Looking up the cost of the Kuuma I came across this in our Seattle store.
They ship free for orders over $99. It may be worth a couple of Big Mac's to check it out.

It may also be worth your consideration to check out the Isotherm heaters. They have an advantage with insolation in that once heated they tend to keep the hot water hot for up to 24 hours.
 
  • Like
Likes: Mooseman
Aug 22, 2021
31
Catalina Yachts 30 Lake Huron
Looking up the cost of the Kuuma I came across this in our Seattle store.
They ship free for orders over $99. It may be worth a couple of Big Mac's to check it out.

It may also be worth your consideration to check out the Isotherm heaters. They have an advantage with insolation in that once heated they tend to keep the hot water hot for up to 24 hours.
Thanks a bunch jssailem! That is a bit cheaper than the next best price I've seen. Were you referring to the Isotemp cylinder shaped ss heaters? I did some looking at them and absolutely like several of the features, but I'm also concerned about some reliability issues that they seem to maybe have as well. Checkout this YouTube video and read the comments from a few others who have had leak issues. One guy is on his 3rd one and it's leaking again...
 
Feb 26, 2009
716
Oday 30 Anchor Yacht Club, Bristol PA
Just a thought and you probably have the connections but you may want to make sure you can connect the engine coolant loop to the heat exchanger on the hot water heater and try to remember to provide a means to purge the air from those lines.
Also if possible get one with the heat exchanger connections on the other side all those connections on the front can make a simple installation complicated looking.
 
  • Like
Likes: Mooseman
Feb 25, 2014
95
Catalina 30 Grand Lake. Wyandotte, Ok.
Have you considered on of the small 110volt instant hot water? I am not sure how well they would work on a boat but I have a small one under a sink in my shop and it does well. Also with the small 12volt pumps that shut off when they reach pressure you may not need a pressure tank. That is what is on my boat and it works well. 8L 1500W Mini Instant Electric Water Heater Tankless Shower Hot Water System 717493283406 | eBay something like that. Anyone have thoughts on this style?
 
Last edited:
  • Like
Likes: Mooseman
Jan 19, 2010
1,169
Catalina 34 Casco Bay
I installed the KUUMA as well. In the attached pic you can see the winterization manifold. When all valves are in the vertical position it is on summer mode. Turning all horizontal, bypasses the tank so that I'm not wasting 6 gallons of RV antifreeze.
IMG_7554.jpg
 
  • Like
Likes: Mooseman
Feb 26, 2009
716
Oday 30 Anchor Yacht Club, Bristol PA
I installed the KUUMA as well. In the attached pic you can see the winterization manifold. When all valves are in the vertical position it is on summer mode. Turning all horizontal, bypasses the tank so that I'm not wasting 6 gallons of RV antifreeze.View attachment 198481
Well done! I used lay out piping l for hydronic heating systems houses and small buildings with radiant floors baseboards radiators boilers heat exchangers water tanks modulating valves circulators... but I hope you most frugal boat owners aware, a kit to bypass a water here can be bought for under $50! There's one on the water heater in my boat surprised me, it will get transferred to the new water heater!
shopping-1.jpg
 
  • Like
Likes: Mooseman
Aug 22, 2021
31
Catalina Yachts 30 Lake Huron
Have you considered on of the small 110volt instant hot water? I am not sure how well they would work on a boat but I have a small one under a sink in my shop and it does well. Also with the small 12volt pumps that shut off when they reach pressure you may not need a pressure tank. That is what is on my boat and it works well. 8L 1500W Mini Instant Electric Water Heater Tankless Shower Hot Water System 717493283406 | eBay something like that. Anyone have thoughts on this style?
Hello Admiral!
Yes, I did consider one of those small instant heaters. The reason that I will likely go with the OEM style heater (like the Kuuma) is because of it's ability to use my diesel engine cooling system to heat water when shore power isn't available. There are many ways to accomplish it, but at the moment, I think that style of heater is going to win out for my boat.
 
  • Like
Likes: jssailem