Water heater mixing engine coolant

[Peregrine1983]

Hi all,

I recently noticed our hot water smells a little like engine coolant, and I suspect our older Raritan water heater's heat exchanger is corroded and allowing some coolant to mix in. This is no bueno for obvious reasons.

Do I have any options to fix this or do I just need to buy a new water heater?

Any help appreciated.

Edit: The heater is a 6-gallon Raritan 1700 series

[jamhass]

Replace it.
Did mine recently, fortunately, it leaked water "out", no contamination.

[djmarchand]

Unlike the antifreeze used for winterizing water systems, engine antifreeze is toxic.

Replace that water heater NOW and don't drink any water, hot or cold until you do.

David

[Peregrine1983]

Originally Posted by djmarchand

Unlike the antifreeze used for winterizing water systems, engine antifreeze is toxic.

Replace that water heater NOW and don't drink any water, hot or cold until you do.

David

Thank you. We never use our boats tank water for drinking anyhow, but obviously don’t want that stuff in the water we use to wash.

[Sparkplug1939]

[QUOTE=Peregrine1983;2685734]Hi all,

I recently noticed our hot water smells a little like engine coolant, and I suspect our older Raritan water heater's heat exchanger is corroded and allowing some coolant to mix in. This is no bueno for obvious reasons.

Do I have any options to fix this or do I just need to buy a new water heater?

Any help appreciated.

Edit: The heater is a 6-gallon Raritan 1700 series[/

[Sparkplug1939]

If you don’t need the hot water heater you can easily eliminate it by connecting the two hoses coming from the engine together.

[AKA-None]

I like free hot water so I’d replace it ymmv

[puffcard]

Replace is the right answer, no way to repair a water heater with an internal failure. But if you are unable to replace, by-pass the engine coolant right away. This is very dangerous, drinking water with antifreeze and I would flush the system after repairs made. If you do jump out the coolant loop, see if it's leaking water out the the engine coolant side. My bet it will, if not leaking. Check the resistance for a low reading, if Sat you might still be able to use the 120VAC heating elements while pierside.



Also if replacing, look at hot water heaters with the water mixing valve, or think about adding one. After a day's run, the water in a hot water heater can be 170F. This temperature is dangerously hot and can scalded you. The mixing valve can limit the output temp to a comfortable temp. Saves water, by not having to let water run till you get a proper temp and is much safer.

[ramblinrod]

Originally Posted by Peregrine1983

Hi all,

I recently noticed our hot water smells a little like engine coolant, and I suspect our older Raritan water heater's heat exchanger is corroded and allowing some coolant to mix in. This is no bueno for obvious reasons.

Do I have any options to fix this or do I just need to buy a new water heater?

Any help appreciated.

Edit: The heater is a 6-gallon Raritan 1700 series

If you were in a colder climate. I would recommend verifying the smell is not from remnant winterizing plumbing antifreeze. If so, the system just needs to be flushed out better and sanitized.

To verify your concerns, disconnect the water heater from the domestic system. Drain the water heater. Run the engine with the drain open with a little pan under it. If coolant is leaking out of the HX loop, it will do so much easier when the potable side of the water heater is not pressurized. If you collect fairly concentrated coolant in the drain pan, BINGO, coolant loop break confirmed.

There is little chance you can repair the tank. Beware that Raritan products are 5 times better than lesser brands and about 3 times the price. Excellent service. Heed warnings about anode maintenance.

[Peregrine1983]

Thank you Ramblinrod. I have a feeling the anodes were never changed by PO's. I think I'm looking at a new Raritan unit.

[Capt Gill]

A technical question: assuming this is a pressurised fresh water system (>20 psi) and the engine cooling system is limited to <10 psi when at operating temp. the opposite would occur, i.e., fresh water would be forced into the engine coolant. If this is true it would be prudent to include this in ones diagnostic parameters.

[roland stockham]

Originally Posted by Capt Gill

A technical question: assuming this is a pressurised fresh water system (>20 psi) and the engine cooling system is limited to <10 psi when at operating temp. the opposite would occur, i.e., fresh water would be forced into the engine coolant. If this is true it would be prudent to include this in ones diagnostic parameters.

It is possible for chemicals to clime up the pressure gradient by osmosis. depends on the pressure difference and antifreeze strength.

[Capt Gill]

Originally Posted by roland stockham

It is possible for chemicals to clime up the pressure gradient by osmosis. depends on the pressure difference and antifreeze strength.

Hmm, "chemicals to clime up the pressure gradient by osmosis", I can't see the connection among the words chemicals, clime, pressure gradient and osmosis, maybe you
can elaborate ?

[ramblinrod]

Originally Posted by Capt Gill

A technical question: assuming this is a pressurised fresh water system (>20 psi) and the engine cooling system is limited to <10 psi when at operating temp. the opposite would occur, i.e., fresh water would be forced into the engine coolant. If this is true it would be prudent to include this in ones diagnostic parameters.

When both systems are fully pressurized, the higher domestic water system pressure would force potable water into the coolant system, which would overflow the reservoir.

However, normally when a pressure pump starts cycling despite no faucet being open, most folks only turn on the pressure pump when domestic water is needed to prevent needless pump cycling due to a leak in the pump pressure chamber or potable water loss due to a leak in the domestic plumbing.

In this case, the majority of the time, the engine coolant pressure will be higher than the domestic water system pressure.

[Capt Gill]

"When both systems are fully pressurized, the higher domestic water system pressure would force potable water into the coolant system, which would overflow the reservoir."
Yes, I agree.

"However, normally when a pressure pump starts cycling despite no faucet being open, most folks only turn on the pressure pump when domestic water is needed to prevent needless pump cycling due to a leak in the pump pressure chamber or potable water loss due to a leak in the domestic plumbing."
If this is the case, (it wasn't stated, so we don't know) then removing the two hoses at the HX & connecting them together, turn on the domestic water pump & heater switch then wait to see if any domestic water comes out of the disconnected HX tubes.
Although the odds heavily favour a defective water heater it's nice to know for sure.

"In this case, the majority of the time, the engine coolant pressure will be higher than the domestic water system pressure."
Yes, if the engine warm to hot and the domestic water pump is off, otherwise no.
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