The PO of Matchmaker had disconnected the hot water heater from the Westerbeke 40 circulation due to overheating issues. I am finally getting around to putting it back right. So, how are you guys plumbed, series with bypass or parallel?
I have a Force 10 heater that I have now plumbed in series with a bypass but am concerned about overheating. The discharge from the thermostat housing goes directly to a reservoir, thence from the reservoir to the hot water heater, and finally exits the hot water heater and back to the exhaust manifold. The hose coming off the thermostat housing is 1.25 inch and then steps down to 1.0 inch and finally 5/8ths before entering the water heater. Returning it goes in reverse back to 1.25 inch on entering the exhaust manifold. That is how is was set up originally. I've just added a 5/8th inch bypass across the hoses before they enter the water heater as recommended by one of the Westerbeke service bulletins. I have still to test it because I need to replace the thermostat first. I am concerned that the 5/8th hose is too small for appropriate circulation. Anyone had experience with this?
Thanks,
Ron
SV Matchmaker
Saint Marks FL
No oil here yet!
The water heater should be plumbed across the thermostat bypass. There are two 1/2" NPT connections at the front of the engine in the top of the cyl head close to the thermostat housing. If your water heater is not connected there, you will probably find plugs in them. The water heater should be connected across those. That way the water heater does not impede the enigine's coolant circulation.
It sounds like all of the coolant will have to circulate through the water heater the way you are plumbed up. The heat exchanger in the water heater and the 5/8" hose usually will not flow enough coolant to keep the engine from overheating. I think I have a bulletin on this- I'll see if I can find it for you.
Thanks,
I was thinking the same thing about the hose reduction. I will look for the connections on the cyl head later today. I found a service bul on using that and coming back to the top of the heat exchanger all with 5/8th hose thus plumbing in parallel last night. That sounds right to me BUT - By feel, there is a plug next to the thermostat housing as indicated in the service bul but it has a wire connection in it and I thought that was the temperature sender connection. Where does your sender connect if that is used for the water heater?
Thanks again,
Ron
Don't remember. I'm going to the boat today- I'll have a look.
Great, thanks
Ron
OK- these backward mounted engines make explanations difficult. So we're going to call the transmission end the rear of the engine. The port behind the thermostat housing on the left should be where you have a sending unit. The other port is located a little further forward and on the right. Should probably just be a plug there. I pulled the sending unit, installed a 1/2 X 2" nipple, then a tee. The sending unit is in the side of the tee. The wire is long enough to reach. On top, another nipple, a ninety and a hose fitting. In the other port, just a nipple (6"?) with a ninety and hose fitting. This gets the water heater in the cooling system shunt, or bypass and out of the main loop. The main loop between the engine and heat exchanger needs to be bigger hose (1.25 sounds right) in order to move enough volume. It is important to keep the sending unit on the original port. That port will be the outlet going to the water heater. If the sending unit gets moved to the other side, it won't sense engine temp like it needs to. Say you are chugging along under power, somebody else is showering or washing dishes, the sending unit will be seeing coolant temp returning from the water heater, which is not the engine temp. So keep the sending unit on the left side. The 2" nipple below it won't affect the operation of it because there will be flow past it.
Great explanation, many thanks. I had a look today too and was considering moving the temp sender to the right side so I'm glad of your warning. The other thing I was considering was using the right hand side port for the output to the water heater. I know that the water will not be as hot but it seems like it could be easier to plumb. What do you think?
Ron
I would use those two ports for the supply and return to the engine. That is how I plumbed ours- it works just fine. The idea is to keep the water heater out of the main loop of the cooling system. You can create problems by having it in the main loop- usually resulting in overheating. This is not to say it can't be done. But plumbing the waterheater to the shunt is pretty foolproof. You are able to get all the heat you want and not create another problem.
The shunt is there for several reasons. Most people are not aware of it. Lets say you start up your engine cold, coolant temp is down. Thermostat is closed. The engine is warming up. The shunt allows coolant to circulate in the engine only. This promotes even heating as the engine comes up to temperature. This coolant is passing by the sensing bulb on the thermostat. If you think about it, if there is no circulation, how would heat to get to the thermostat to start it opening? The cyl head would probably hotspot and crack first. The W40 uses I believe, an orfice for the control on the shunt. It allows a limited amount of coolant to circulate internally while the thermostat is closed, so that when the thermostat opens the majority will go to the cooler. That same orfice is what is going to give you the pressure differential to get the coolant to flow through the water heater. This "sidestream" flow through the water heater is fine as it is the least intrusive to the rest of the cooling system.
Great explanation. Thanks. Your points are well taken. I'll be copying your plumbing over the next week.
Best,
Ron
All,
The following link is to the Westerbeke Service Bulletin #95 concerning domestic hot water heaters installation
http://www.sailingseadragon.com/Manuals/DomesticHotWaterHeaterSBulletin7July1980.pdf
I am in the process of reconfiguring the cooling system on Sea Dragon to match the bulletin.
Dirk on Evening Ebb is the only owner I know of that has made the modification.
Garner
Garner,
I have a service notice that Service Bul #95 is superseeded by Drawing #23456. This drawing has the water heater plumbed in parallel as described by Ray above. The 5/8th inch heater hose coming off the port to the left of the themostat housing and going directly to the water heater inlet. Then from the water heater outlet to a remote coolant tank (required when water heater is above the engine). And finally out of the remote coolant tank back to the engine. Ray has his return in the port to the right of the thermostat housing. The drawing has the return entering the top left (as you are facing it) of the heat exchanger. Since I can't move the frozen port to the right of the thermostat I'm going to the heat exchanger. I would think either should work. Send me your e-mail address and I'll scan and send you a copy of the drawing if you like.
Ron
Ah!- So that's where they want the tank. I was not really happy with the way ours is plumbed but it works, so at least for now, the plan was to leave it be. Something else for The List...
I'm happy to scan and send anyone who wants the diagram I have at hand. Just let me know your e-mail. You can reach me directly at rc_norton@hotmail.com
Ron
A year or so ago, I spoke with the Westerbeke representative about solutions for the reduction in the coolant lines at the hot water heater. He advised me to use the solutions contained in Service Bulletin 95. I have a 1 1/4 inch line running from the thermostat housing to the coolant reservoir and from the reservoir to the hot water heater where it steps down to 5/8 lines through the heater and then back up to a 1 1/4 line that runs back to the exhaust manifold. Close to the hot water water I placed the fittings on both sides for a 5/8 line bypassing the hot water heater. For the last year-plus the engine's run at 175-180 degrees even in the recent hot weather and last week's 82 degree bay water. [The Westerbeke representative also suggested taking the coolant reservoir out of the system and using it as an alternate fill/overflow reservoir by having a single line run from near the hot water heater up to the reservoir. I didn't do this.]
Our local diesel mechanic has been recommending RydLyme Marine (http://www.rydlymemarine.com) to clean heat exchangers in place. Introduce it into your system just like you would anti-freeze when you winterize your engine and let it sit for an hour or two. Then run the engine to flush the lines and your heat exchanger should be quite a bit cleaner. It's been quite effective for several boats on our dock.
Dirk
RydLyme is good stuff. I used it for years here at work. 3 drums at a time to clean marine growth out of some heat exchangers. It did us a good job. The only issue we had with it was that it is a one shot chemical. We have gone to a hotter acid that can be reused several times.
hi, I saw a Westerbeek bulletin with a schematic, and made a drawing that's easier to read of how we piped in our replacement hot water heater, (for the next time). email me at greg4706@yahoo.com and I'll send it to you,
gp
Quote from: RayNWanda on July 18, 2010, 06:49:00 PM
OK- these backward mounted engines make explanations difficult. So we're going to call the transmission end the rear of the engine. The port behind the thermostat housing on the left should be where you have a sending unit. The other port is located a little further forward and on the right. Should probably just be a plug there. I pulled the sending unit, installed a 1/2 X 2" nipple, then a tee. The sending unit is in the side of the tee. The wire is long enough to reach. On top, another nipple, a ninety and a hose fitting. In the other port, just a nipple (6"?) with a ninety and hose fitting. This gets the water heater in the cooling system shunt, or bypass and out of the main loop. The main loop between the engine and heat exchanger needs to be bigger hose (1.25 sounds right) in order to move enough volume. It is important to keep the sending unit on the original port. That port will be the outlet going to the water heater. If the sending unit gets moved to the other side, it won't sense engine temp like it needs to. Say you are chugging along under power, somebody else is showering or washing dishes, the sending unit will be seeing coolant temp returning from the water heater, which is not the engine temp. So keep the sending unit on the left side. The 2" nipple below it won't affect the operation of it because there will be flow past it.
I think I mistook this sender to be my oil sender ...where is the oil and temperature sender located on your motor?