Water Heater Install in O'Day 34

Nov 13, 2020
89
Hunter H34 Chesapeake Bay
Hello all. New member here, although I"ve been lurking about Hunter and O'Day boats for a while.

I looked at a 1984 O'Day 34 today and I'm seriously considering buying it. It is in very good shape and at a good price. My only hesitation is that it does not have a water heater - and I want hot water for extended cruising comfort. When the owner said it didn't have a water heater, I didn't think (at the time) to ask if it ever had one. I'm trying to find that out now. If it never had one, how difficult will it be to install one, and all the plumbing? I've fairly mechanically inclined and would plan to do it myself. I find it interesting that it doesn't have one, especially since it has what appears to be factory refrigeration. That's based on the refrigeration breaker label that appears to be from the factory.

Thanks in advance for your input. I'm looking forward to joining the O'Day community.

John
 
Jan 7, 2011
4,723
Oday 322 East Chicago, IN
Not too difficult to install one from scratch, but certainly easier if there was one in there previously.

Maybe someone with a O34 will comment on where it SHOULD be. On my 1988 O322, the water heater is Installed in the lazzarette.

You basically need 110 power to the water heater assuming you will heat with shore power electricity. A separate breaker on your AC panel is important.

Secondarily, many water heaters can heat the water with the engine coolant. On my O322, I have hoses that come off the engine coolant system (anti—freeze) to a heat exchanger on the water heater and back to the engine. This is a great feature to give you some hot water when away from the dock.You need to decide if you want this feature when you order your WH.

Other than that, you need cold water hose to the WH, and hot water supply hose connected to the HW side to the faucets.... I am curious how the hoses are run if the boat never had HW. Seems hard to believe any fairly modern boat didn’t have provisions for hot water.

Lastly, you need space for one....I have seen them installed under settees, in bow V, in the lazzarett, etc.

Good luck and have fun...

Greg
 
Aug 7, 2018
179
Catalina 350 Great Sodus Bay, Lake Ontario
On my Oday 34 the water heater was factory installed in the port locker next to the galley. The plumbing was factory installed through the floor. If the supply and return lines are there it is an easy install. If not, you’ll need to remove the floor below the stove to fish the lines to the port water tank, that will get interesting. If the lines are there you should be able to install a by-pass and a new heater in a few hours. There should be a breaker for the hot water heater or room for one @ the ac panel.
 
Nov 13, 2020
89
Hunter H34 Chesapeake Bay
Not too difficult to install one from scratch, but certainly easier if there was one in there previously.

Maybe someone with a O34 will comment on where it SHOULD be. On my 1988 O322, the water heater is Installed in the lazzarette.

You basically need 110 power to the water heater assuming you will heat with shore power electricity. A separate breaker on your AC panel is important.

Secondarily, many water heaters can heat the water with the engine coolant. On my O322, I have hoses that come off the engine coolant system (anti—freeze) to a heat exchanger on the water heater and back to the engine. This is a great feature to give you some hot water when away from the dock.You need to decide if you want this feature when you order your WH.

Other than that, you need cold water hose to the WH, and hot water supply hose connected to the HW side to the faucets.... I am curious how the hoses are run if the boat never had HW. Seems hard to believe any fairly modern boat didn’t have provisions for hot water.

Lastly, you need space for one....I have seen them installed under settees, in bow V, in the lazzarett, etc.

Good luck and have fun...

Greg

Thanks Greg.

John
 
Nov 13, 2020
89
Hunter H34 Chesapeake Bay
On my Oday 34 the water heater was factory installed in the port locker next to the galley. The plumbing was factory installed through the floor. If the supply and return lines are there it is an easy install. If not, you’ll need to remove the floor below the stove to fish the lines to the port water tank, that will get interesting. If the lines are there you should be able to install a by-pass and a new heater in a few hours. There should be a breaker for the hot water heater or room for one @ the ac panel.
Thanks David. I think I need to go back and take another look with this in mind. I"m not sure I want to take on running the plumbing lines.

John
 
Aug 17, 2010
311
Oday 35 Barrington
The water heater in the O'day 34/35 was an option, and if installed would be mounted in the forward end of the lazerette. My O'day 35 had a Seaward 6 gallon hot water heater (looks like an aluminum box) instead of the round water heater that O'day would have included.

My domestic hot water is heated by either 110VAC (there should be a breaker for this) or the engine's coolant circuit. If you are installing from scratch, and you want hot water from the engine's waste heat, I suggest that you should plumb the connection to the coolant into the thermostat bypass loop, and not between the heat exchanger and exhaust manifold, as the factory would have done.

The breakers labeled "REFRIGERATION" and "STEREO" were installed at the factory in most O'day 34/35s, regardless of whether these options were actually installed.
 
Aug 7, 2018
179
Catalina 350 Great Sodus Bay, Lake Ontario
"My domestic hot water is heated by either 110VAC (there should be a breaker for this) or the engine's coolant circuit"

As stated above you can heat the water with 110 volts or the engine loop but will need to buy a heater that accommodates both if you plan to use the engine loop. Watch for scalding if you have kids onboard I am not sure if your heater can set max temp. Mine could not.
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
You should also tell us what engine you have if you buy the boat and we can explain in more detail what @eherlihy explained
If you are installing from scratch, and you want hot water from the engine's waste heat, I suggest that you should plumb the connection to the coolant into the thermostat bypass loop, and not between the heat exchanger and exhaust manifold, as the factory would have done.
The other question is if the boat has a domestic pressure water system or not. If it does, it "should be" easier.
 
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Nov 13, 2020
89
Hunter H34 Chesapeake Bay
Great info guys. Thanks.

It has an M25 engine and currently has a pressure water system. I've read posts on other forums that mention water heaters being removed due to engine overheating and heat exchanger issues. I also saw a post about plumbing it via the thermostat bypass loop. All great ideas.

Another interesting point about this boat is there isn't an engine runtime meter.

John
 
Aug 17, 2010
311
Oday 35 Barrington
The M25 is a good engine. I have one in my O'day 35. The M25 is based on a Kubota D850 tractor motor, so MOST parts are readily available at 1/3 the "Marine" cost from tractor dealers. The major parts that are not available are the timing case cover, and the exhaust manifold. To protect the timing case cover, make sure that the alternator bracket has been updated. To protect the exhaust manifold, make sure that the coolant has been replaced every 3 to 4 years.

Many O'days left the factory without an hour meter. It is EASY to add one, and you should do so if you buy the boat.
 
Sep 11, 2016
12
O'Day 30 Halifax, Nova Scotia
We just picked up a 1984, O'Day 34 and there is a hot water tank in the port side lazarrette [sic].

It runs from the engine (M25 Universal), like a heat exchanged and maybe a 10 gallon tank. Run the engine 15 minutes and shower...
 

Arrgh

.
Oct 27, 2021
48
ODay 34 Bristol, RI
Although not standard, it may be easier to install, my 34 has an on demand propane heater...
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Although not standard, it may be easier to install, my 34 has an on demand propane heater...
What's the make and model of the water heater? Is it currently available?
 
Sep 11, 2016
12
O'Day 30 Halifax, Nova Scotia
Does any one use these (Only related to this thread), I grabbed one for our last boat and purchased a new boat this year. I'm comfortable with this external system, but may not install it before selling to a new owner.
 

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