New hot water heater in 32-3

[peaman]

I recently replaced my original 6 gallon Atkins hot water heater with a new 5.3 gallon Isotemp Spa unit. So these last two seasons, we have avoided using any hot water because it was always foul, even though I had done everything I could to make it useable. The heater itself was inconveniently placed, and the steel casing had a fair amount of rust, so I ditched it. Sources suggested that foul smells could come from tank anodes, but after disassembly of the entire unit (necessary for removal from the boat), there were no signs of any anode.

Like others who have done the job, I had to make some modest cuts in the fiberglass at the cockpit hatch. It was only about 3/8" at inboard and outboard edges, so no big deal. That small adjustment permitted removal of the bare tank of the old heater, and also for the from-the-factory assembly of the new heater.

I placed the new heater at a diagonal angle in the boat to optimize space and access. The area of the rudder post, and also the area starboard of the engine both have improved access with the new heater arrangement.



I connected the heater with in- and out- isolation valves, and also a bypass valve, so the heater tank can be easily bypassed for winterization of the rest of the plumbing system, while the tank itself is drained for the winter. Existing Qest piping was found to be compatible with 3/8" PEX, which was used for new connections, using SharkBite Brass Push-to-Connect fittings.

The Isotemp heater is fitted with a specialized combination cold water inlet / drain valve, and also a specialized combination hot water outlet / temperature controlled mixing valve. Together, they provide for a user-selected maximum outlet temperature, which will reduce the potential for scalding, while improving the effective capacity of hot water storage. The stainless steel supports and tank, with the plastic exterior of the heater should ensure a long corrosion-free service life.

 

[Christian Williams]

Very nice.

It's important that the first connection on the heater be brass (heat distorts Pex or similar). My boat had a persistent leak at that joint until I wised up to that warning.



Here's the install of a Kuuma water heater on a 32-3.

 

[peaman]

Funny you should mention that. The hot water mixing valve is brass, but it has a stainless steel adapter with male pipe threads. My first fitting is a red brass street elbow, and I have been frustrated with stopping a very slow one drop-per-55 seconds leak where the elbow mates to the adapter. I used standard Teflon tape, three wraps, and I re-made the joint with this elbow after discarding a yellow brass street elbow which would not seal on the third effort. I have done plenty of pipe before with no issues. I may decide to try again, maybe with the double-thick yellow Teflon tape, or maybe I will ignore it mostly. I don’t need hot water on day sails.

 

[ConchyDug]

They make high temp liquid sealant for pipe threads works about 1000 times better than Teflon tape.

 

[G Kiba]

You probably know this already. But just in case. There are two types of pipe thread. Straight and taper. Make sure you have fittings of the same type. A street elbow is likely tapered.

 

[peaman]

Thanks, but yes. The cold water line connected no problems. The adapter threads (male) are clearly tapered. I threw out the brass elbow I tried first, on concern it might not be tapered. If it doesn’t “self heal”, I guess I’ll find some liquid sealant.