hot water help please

[bamboo]

Hello all,

Iam new to the forum, 1st time post and Im sure not the last, in fact you will not be able to get rid of me all the info is great. My wife and I have been refitting a Fisher 37 and are setting off in Sept. Todays problem is the new hot water heater install. The coolant pipes that I am suppose to tap into are 1 1/4 inch and the fittings at the tank are 1/2 inch. Am I suppose to reduce the hose size to that meas. it seems drastic and my thinking is that it will starve the engine of the proper flow? Any and all input is apprec. Thanks Randy

[never monday]

Originally Posted by bamboo

Hello all,

Iam new to the forum, 1st time post and Im sure not the last, in fact you will not be able to get rid of me all the info is great. My wife and I have been refitting a Fisher 37 and are setting off in Sept. Todays problem is the new hot water heater install. The coolant pipes that I am suppose to tap into are 1 1/4 inch and the fittings at the tank are 1/2 inch. Am I suppose to reduce the hose size to that meas. it seems drastic and my thinking is that it will starve the engine of the proper flow? Any and all input is apprec. Thanks Randy

Don't cut any hoses on the engine.


What engine is it?

[Pete the Cat]

HOLD ON.... Seems like you might be hooking up the engine to your freshwater system! Maybe your new water heater does not have an exchanger in it (which would have a larger intake and output)? Some of them don't if you do not order it that way.

[phorvati]

It wouldn't hurt to specify the engine and waterheater models. My guess is that you are looking at the 1-1/4" exhaust hose. Most sailboats in the 30 and 40 foot range have radiator hoses less than 1". More like 1/2"-3/4".
Petar

[bamboo]

Well, we have a 80 ford sabre engine and its a isotemp slim square heater. The coolant hoses are definatly 1 1/4. Since my post I was told I could use the temp sending unit port and install a "t" and install temp unit on the top. But as far as the return goes Im not sure how to handle it?

[imagine2frolic]

Unless your in the artic, or at the dock. Forget the hot water heater, and invest in a tea kettle.............

[bamboo]

The 5 quart aluminum is the back up been using that for 10 years. Its time to treat ourselves.

[never monday]

Originally Posted by bamboo

Well, we have a 80 ford sabre engine and its a isotemp slim square heater. The coolant hoses are definatly 1 1/4. Since my post I was told I could use the temp sending unit port and install a "t" and install temp unit on the top. But as far as the return goes Im not sure how to handle it?

Look on the circulating coolant pump. There should be a port with a plug in it. If not you can t a block drain.

[hellosailor]

Randy, in the interest of not making assumptions...is your engine cooled with a closed loop and heat exchanger ("fresh water cooled") or directly with outside raw water? ("raw water" cooled).

Pat, wouldn't installing a "T" with a relatively heavy hose on it be tempting the fates, in terms of possible vibration failure breaking the "T" fitting down the line?

Randy, there's an unwritten law about boat plumbing: Whatever fitting you need, no one makes one in that size. If you have metric, you need inch. If you have inch and metric, you need Whitworth or a different thread pitch. And if you have all that stuff lined up, whatever you have is made of an incompatible material and you'll have to make do with something cobbled together with a great deal of plumber's epoxy and stainless clamps, or worse.[g]

It isn't just your installation, this is normal on boats. Take your time with figuring it out, work on it till the solution seems as elegant as it can get.

[never monday]

that large of an engine should be closed cooled. Vibration can be an issue. But remember were not dealing with salt water. Galvanized pipe will work for this install.

Randy can you email me some pics of all sides of the engine?

[bamboo]

Its a fresh water {anti freeze system} There is no plug on the water pump. Im comfortable using the coolant temp sender as my inlet and I have seen a return on this engine that goes into the header tank but I have no plug there so Im not sure if it was drilled and tapped or their engine just had it factory? I do not think Im comfortable drilling and tapping the header tank because I think its cast metal of some sort and I would think the wall thickness would not be thick enough to support it?

[hellosailor]

I wonder if it would pay to take a couple of pieces of straight 1-1/4" straight pipe to a welding shop, and have them weld on a low-angle "Y" stub of 1/2" pipe? So that the main coolant flow was still carried completely in the full diameter, but the water heater was just "sipping" some flow off to the side through the "Y" stub, and reinserting it again the same way?

Existing fitting=>existing hose=>new Y=>existing hose......

And the same way at the other end, so that cutting the existing hose, or pushing it back, and inserting a new "Y" with a short length of similar hose, was all that was required. Along with some new hose clamps.

That way everything is also plug-and-play, and can come out again by just opening up the hose clamps and removing the new "Y" stubs.

[cantxsailor]

I bought one of the on demand propane setups from Zodi. It's more of a camping kind of a thing but it really puts out the hot water and for about a $100 it's pretty cheap. I find on my small boat not everything has to be(can be) built in and at the cost of "marine" type systems mostly they're just out of my reach.....martin

[bamboo]

Thank you everyone for your input I got back to the boat finally today and figured out what Im going to do. The input to the hot water heater will come from a "t" that I installed where the coolant sender was and the return will go to the header tank, I found a freeze plug, the area is thick with material so I will pop that plug out, tap it and install the proper fittings for me to connect. Thanks again Randy