Community Forums

dvleemin · 05-31-2014, 03:38 PM

Hi,
I was in process of installing a new hot water tank that has a heat exchanger on it. When I went to disconnect the radiator hoses from the back of the old hot water tank I couldn't get the anitfreeze to stop coming out. I was expecting some to come out - the portion that is in the lines inside the hot water tank, but not that much. I finally put the hose back on so I would so losing anti freeze. I did check and the engine heater switch is set to off in the RV.

Any thoughts on what I'm doing wrong or missing here?

Darryl

Skip426 · 05-31-2014, 03:48 PM

If the water heater is lower than the top of the engine radiator the A/F will continue to flow out till it seeks it's own level.
Look under the coach by the transmission , many chassis makers put shut off valves in the heater hoses there; so they can be isolated in case of failure.

dvleemin · 05-31-2014, 03:52 PM

Quote:

Originally Posted by Skip426

If the water heater is lower than the top of the engine radiator the A/F will continue to flow out till it seeks it's own level.
Look under the coach by the transmission , many chassis makers put shut off valves in the heater hoses there; so they can be isolated in case of failure.

Thanks. So what does the engine heater switch do then? I assumed it would shut off the valve to the hot water heater, no?

Shadow0120 · 05-31-2014, 04:10 PM

Turns on the electric engine block heater or a heater in the oil pan.

Skip426 · 05-31-2014, 04:16 PM

Engine heater ?

Do you mean the dash control , off, for the dash heater ? The shut off for the dash heater is right at the heater core at the front of the motor home and only stops flow at that point , so the dash A/C can do a better job , by not having to cool a heated chamber in the dash before the air gets into the passenger compartment. Anywhere else in the heater hose system you get full flow from the engine / rad as soon as you open a line.

dvleemin · 05-31-2014, 04:16 PM

Quote:

Originally Posted by Shadow0120

Turns on the electric engine block heater or a heater in the oil pan.

Thanks.

I just went under the RV and I can't seem to find a shut off valve . ..

OLYLEN · 05-31-2014, 06:37 PM

Unless you have the agua hot system which it appears you do not the dash preheat switch controls the block heater(120 volt shore or Gen power). The Water heater line to the radiator heats the hot water tank(fresh water) from the motor while underway, so when you arrive you have free!!! hot water. To stop the anti freeze from the radiator use a vise grip and pinch the line/lines until you can reconnect with the new tank.

LEN