On a scale of 1-5

[djousset]

I need to replace my Raritan hot water tank (with heat exchanger to Yanmar 2GM20f). I've got everything I need and have watched a You Tube video a few times. They make it look easy, and maybe it is, or isn't.... On a scale of 1-5 what skill/tenacity/patience level is needed? Can a newbie handle this in a couple of hours with a smile on her face like the guy in the video?

[Calif.Ted]

I have not seen the video but: If possible do not allow the coolant to drain from lines, if air is in the system you'll need to bleed and that can be problematic.

[Stu Jackson]

If 5 is hardest, this is a 2, maybe a 1. You need a screwdriver to get the hose clamps off & on, and maybe a long screwdriver to undo the base of the heater. The rest is just gymnastics. I did mine in 2013. Bleeding air out of the coolant system is easy: hold one of the hoses at the engine up higher than the engine and pour antifreeze into it.


You CAN do it.

[PippaB]

As with anything on a boat, the real difficulty will be in getting you and your tools into whatever compartment, along with the old water tank, and then managing to do the work in that area. Disconnect 4 hoses, maybe an electrical connection (do you also have electric heat in the tank?), then it is remove, replace, re-connect. As CA Ted mentioned, you will likely end up with air in the coolant system (even if you keep the hoses full you would also have to fill the new heat exchanger with coolant and then manage to hook it all up without spilling anything).

When I did this I put a tee with a valve at the highest point in the coolant loop, preferably in the line that is the return from the tank to the engine. Attach a hose to the valve. If you can route it that way, run the hose to the coolant expansion tank on the engine (if it has one), otherwise to a bucket. Start the engine, open the valve, bleed out the air. If the hose goes to the expansion tank you don't have to do much else except top up the coolant after the air is out (depending on how much air you may have to do this a couple of times). If you used a clean bucket, you can just take any coolant you captured and put it in the coolant system. If you do all this relatively quickly the coolant won't get much above warm, but do be careful, it can be quite hot.

Overall, 2 or 3 on a scale of 5.

[Cpt Mark]

As stated above. Does it work off electricity? Make sure that breaker is off. Test the wires to be sure.
One of these and a heat gun or hair dryer will make getting those hoses off easy.
https://www.amazon.com/OTC-4521-Hose...d_bap_d_rp_1_t

Alternatively just cut the hose off the barb if it's metal if you have enough extra hose.

This is a 1 job.

I just replaced mine with one of these https://www.westmarine.com/buy/isote...58?recordNum=7

What I love about it is it has the mixing valve at the hot water outlet. I set it to the temp I like my showers and now just turn on the hot water. It mixes with the cool water and it's always the right temp. All my showers (I have a cat) and sinks have the same temp water. If you've already bought another brand that doesn't have you can buy the mixing valve at any big box store or plumbing store. One of my fav boat mods ever.

[Bent Bugle]

Skill level is about a 1.5 - 2, I just replaced mine, whether you're still smiling after a couple hrs is directly related to the amount of boat yoga required to do the job...if it's a straight swap it's pretty basic, but take a photo of the original installation anyway. Use heat to separate the hoses, if you can't get them apart just cut them, there's usually enough length to re-fit the connections- replace the stainless clamps using decent quality 316,to make it easier getting the hose onto the barb fittings heat the hose end - you can boil some water in the kettle,put it in a cup, & dip it in (that's if you haven't got a heat gun). If you have to add length to the hoses use straight barb fittings & reinforced hose rated for high temp- the engine temp is up about 190 or so..Try to keep as much coolant in the eng hoses as possible, take the cap off the reservoir when you test the system & the air should end up bubbling up through there...

[deblen]

Get yourself a 5/16" Nutdriver for the hose clamps. Way ahead of a flat blade screwdriver. Get a 1/4" one also for the future, for the little hose clamps on fuel lines,etc.


https://www.homedepot.com/b/Tools-Ha...vZc21zZ1z19uc0

[djousset]

Thx all, I very much appreciate the input.

@ Calif Ted: I've played the air bleed game and it was NOT enjoyable, thx for the tip
@StuJackson: Thx for the vote of confidence
@PippaB: I'm on the small side and fit comfortably in the lazarette, elec is an option but will not be used here
@ CptMark: No electric, heat gun ����. I'll check on the mixing valve but I think not.
@ Bent Bugle: Good tip on photo, thx. I'm good with yoga!
@deblen: +1 on the nut drivers for those clamps
@raisedkk36: Thx for the offer, will PM you

[Chotu]

After many years of experience doing these types of things, decades, I can safely say that getting the old hoses off of the hot water heater will be the worst part of the job.

I hope it stays at a #1 or #2 for you.

[waterman46]

Originally Posted by deblen

Get yourself a 5/16" Nutdriver for the hose clamps. Way ahead of a flat blade screwdriver. Get a 1/4" one also for the future, for the little hose clamps on fuel lines,etc.


https://www.homedepot.com/b/Tools-Ha...vZc21zZ1z19uc0

I had a lot of old hose clamps on my boat that were 3/8. You can get a handle to fit yout 1/4" drive hex socket set.

The hose connections on my hot water tank are about the lowest point of the engine coolant system. I would drain all coolant from the heat exchanger before disconnecting those hoses, and have somehing available to catch spillage.

I have never had to bleed air out even when I replaced all hoses in the system. Just fill at the heat exchanger cap, run engine a few minutes, stop, top off

[NorthCoastJoe]

It should be easy, as others have stated bleeding can be a pain. I would replace the hoses while your doing this work.i To me the best way to bleed the system is a "T" at the highest point open it with the engine running to clear the air. If you don't have a "T" then leave a hose loose at the highest point to clear the air with the engine running.

[Quadrille in JB]

Every packing gland I have ever serviced has been very hard to remove the old packing. This is normal after it’s been compressed and heated overtime from friction.
I use a tool that looks like a screwdriver with a 90° bend at the end.
Here is an example from Amazon but you can buy a set of three at Harbor freight for about the same price.
It starts out looking a lot harder than it is. Once you get some loose it comes out pretty easily. It is not a good practice to just add more and leave the old stuff in
I have seen some boats with vee drives that had to have the transmissions removed to service the stuffing boxes. Poor engineering!

[Chotu]

I wanted to add one more thing. If you have slack and you cannot get those old houses off, sometimes it’s better to just cut the hose off, and then work on cutting the remaining piece off of the fitting on the hot water heater.

This will save cuts to your hand and smashing knuckles.

[Quadrille in JB]

Sorry but I replied to the wrong post.
That’s what happens sometimes as we grow more “mature.”

[SofaKingFishy]

I just replaced mine- piece o’ cake as long as you’ve access. Plumb everything & attach to the tank with barbs & a short run of hose. Use spade connectors for the electric if a butt is impossible to crimp.