Can I plug fitting from HE to water heater?

[Mikelikethewind]

I will never use the ancient water heater on the boat, can I just plug the fitting from the heat exchanger to water heater and be done with it?

Also I think this will do away with having to burp the coolant system whenever I change the coolant as the heater will no longer be the high point in the system.

[exMaggieDrum]

That would depend on how your whole system is plumbed. You just need to make sure that the system was not dependent on the outflow from the water heater (if that makes sense to you). But if you don't need the water heater then you would definitely want to disconnect it as it would be a potential leak with possible catastrophic problems. The best way to plumb these types of systems is a separate heat exchanger just for the water heater in which case you would have to remove that heat exchanger and replace it with a hose from the inlet to the outlet side of the engine coolant flow. If the engine coolant flows through the hot water heater and then back to the engine you still have to maintain that flow for the engine itself after removing the hot water loop. Otherwise you just block the engine coolant system which will overheat the engine almost immediately.

[Bill Seal]

Like he says, don't block it, bypass it. Same as how you would bypass your car heater if it started leaking.

[leftbrainstuff]

Originally Posted by Mikelikethewind

I will never use the ancient water heater on the boat, can I just plug the fitting from the heat exchanger to water heater and be done with it?

Also I think this will do away with having to burp the coolant system whenever I change the coolant as the heater will no longer be the high point in the system.

There will be an inlet and outlet from the he to the water heater. You'll need to bypass the heater on the he side.

You cant just block ports.

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[zboss]

Why not put in a set of bypass valves? That way you can use it when you want without unhooking it.

[Bacchanal]

My water heater recently had a leak in it where the engine coolant was getting into the hot water. I bypassed the water heater by making a loop at the engine that allowed the water to just circulate back to the engine through a 1 ft. hose. I plan to replace my H.W heater in the fall, so this can easily be reversed. I like Zboss' idea of installing shutoff or bypass valves and will probably add those during the install.

[Steve OBrien]

You can just plug the hoses to and from the water heater. Engines are not designed to be dependent on cooling from the water heater, otherwise they would overheat once the water heater got hot. My water heater holed through on the coil, and I had to plug it off to keep all the fresh water (~30 psi) from draining into the engine heat exchanger (~3 psi). Ran that way for about 9 months until I got somewhere where I could get a new water heater.

[wunderluster]

Just loop the inlet and outlet hoses with a coupling. Mine was looped for a year after I bought my boat. When I installed a water heater I just attached the hoses to the inlet and outlet ports on the heater.

[lancelot9898]

I recently changed out the antifreeze on my Perkins 4108 and now the engine is running about 10 degrees hotter (190 vs 180) than before the change. I'm concerned that there might be an air lock, but if that was the case it would show a higher temp.? I do have a hot water heater that takes fresh water from the engine and then returns it and I also have taps that can be closed on those hoses. I'll close those taps to see if the engine runs cooler and if so then I'll make a better effort to completely fill those hoses with antifreeze.

[exMaggieDrum]

Originally Posted by zboss

Why not put in a set of bypass valves? That way you can use it when you want without unhooking it.

Good idea. Actually I would do this if I were putting in a new one in any case. Water heaters do not have long lives and there will be times that you want to remove them from the loop on a temporary basis.