Nomad Willy
Guru
My Willard has that feature and the domestic water gets too hot.
I guess I dont get it, most places I use shower or faucet handles work the same. Right cold, left hot, a little of both, warm. Adjust to pleasure.
If I cant handle that setup, hard to believe the state allows me to drive both a car and boat.
A few engine mechanics have said to me that they do not like to see the engine coolant running to a hot water heater due the possibility of failure of one of these hoses. If you overheat a very expensive diesel engine the cost to rebuild is very high. If you are running a generator anyway like we do in Florida most of the time for air conditioning, they say it is not worth the risk for hot water. Shut off valves might be a consideration to have on the extra coolant lines closed when not needed.
A few engine mechanics have said to me that they do not like to see the engine coolant running to a hot water heater due the possibility of failure of one of these hoses. If you overheat a very expensive diesel engine the cost to rebuild is very high.
Very good point, but with a proper set up and hoses check, as well as the hot water heater, how high is the risk? I'd hope very low.
If this was really a risk, you wouldn't see heat exchangers in water heaters and boat manufacturers wouldn't manufacture them this way. The risk of a hose breaking is pretty slim if you use quality hose suitable for the purpose and route it in a safe manner.
I did once have a hose fail in a water heater coolant loop, and it did drain most of the coolant into the bilge. A support had come undone and the hose fell to where it was chafing on the tiller arm.
Exactly what happened during delivery of my 47 Eastbay. Coolant loop from starboard engine failed due to a brass elbow at the engine with a valve hung off it. Hose was supported, so it wasn't bearing the entire weight of the valve at the elbow... but still a lesser design than I'd chose.
Upside was the engine immediately reported the alarm and we shut it down.
Exactly what happened during
We will likely run the generator a lot and I may consider not re-connecting the loop. One less thing to puke out $200+ worth of coolant...
Ski,Have seen a couple of engines wrecked due to water heater loops. One a fitting with a valve was cantilevered and broke off at thread roots. Used a brass nipple where it should have been steel, or valve located after a section of hose.
Other one a mechanic changed coolant, and water heater drained too. When refilling, a large air pocket was in water heater and once up at power the air slug moved into engine, air loading the pump. The temp sensor did not sense the heat as the flow had stopped. Finally alarm came on but by then engine was cooked.
On my personal boat with single engine, no loop to water heater. Much cheaper water heater (domestic type) and I run the gennie in the morning and pm anyway. I don't miss the feature.
I do use engine coolant for cabin heat, but on winter runs I use that for hours on end, so pretty valuable. I close the valves off in the spring.
Ski,
As I am about to change my heater with a new one what would be your advice to avoid air locking the pump?
I plan to fill up the heater with coolant by gravity feeding it, any other thing I should be careful with?
Also I will add shutoff valve at the engine block, as the block is cast iron what type of fittings are the best, steel, brass, bronze?
I will replace the engine fittings as they show some sign of aging.
Lastly if I put shutoff valve will the coolant bypass internally or do I need to add a loop between in/out coolant fitting on the engine?
And for hoses, regular rubber hose for coolant? Silicon hoses? Any advice for these?
Sorry for the slight thread hijack