Tying in Espar into coolant system?

I’m adding a D5 hydronic Espar into my Sprinter that did not originally come with a pre heater. The main reason I’m doing this is not for pre-heating but for aux rear heat and hot water without idling. It looks like my current heat exchanger routing comes off the intake manifold goes to a circulation pump then T’s to go to the heater core and the water valve then the heater core goes to the water valve from the water valve it goes to the water pump. What is the function of the water valve and how does it work?

I’m thinking of tying the system in like this:
Stock: Intake Manifold > Recirculation pump > T to bypass heater core > heater core > water valve > water pump
W/ Espar: Intake Manifold > Recirculation pump > Espar > rear heat exchanger > water heater > T to bypass heater core > heater core > water valve > water pump

I’m going to run a bypass with a ball valve with T fittings at the in/out of the hot water tank and the aux heat exchanger. This way if the ball valve is open the water will mostly flow around the hot water or rear heat exchanger when not in use.

Anyone have any suggestions or recommendations? I’ve never installed one of these and want to get it right. I’m concerned about keeping my stock cooling system working properly with the recirculation pump and water valve.

It's certainly been done. I suggest asking on expeditionportal.com as well as calling espar.

I would like to do this too, as it also uses residual engine heat for rear heat. But I would want to make sure I can easily isolate the system. Also, I think it's necessary to think about hot water in the summer without adding heat to the rear. Even if the fan is off on the watre/air heat exchanger, there will still be heated air. You've probably seen the marine water/water 6 gal heat exchanger. That should work well after driving, even without the espar running.

Please post here as you figure this out.

Cuervo said:

I’m adding a D5 hydronic Espar into my Sprinter that did not originally come with a pre heater. The main reason I’m doing this is not for pre-heating but for aux rear heat and hot water without idling.

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Mmmm ..... lemme see if I understand this - you are planning on using a Hydronic, plumbed into your vehicle's cooling system (which contains anti-freeze - a violent poison, with no antidote) to heat "hot water" ....

.... you wouldn't be planning on that hot water being used for drinking or cooking would ya ?

Anyone have any suggestions or recommendations?

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If you are planning on using the "hot water" for drinking or cooking ...... fuggaddaboutit .....

These are seperate systems. That's why there's a water to water heat exchanger. Otherwise there would be a lot of dead yatch owners.

dz,

I full well understood that they were separate systems when I wrote what I did above - separate initially doesn't preclude the possibility of a failure between the two systems, and leakage from one to the other. Personally, I wouldn't do it - for the reason stated - but that's just me.

So back to the point... Does anyone know how the water valve works on the sprinter??

As far as the antifreeze, I'm not to concerned of heating my water with it as it is commonly used on boats. I won't be drinking it anyway. Thanks for the reminder!

From the '03 service manual:

"The automatic temperature control (ATC) system
controls interior temperature by taking actual values
from the temperature sensors and the CAN bus and
comparing them to the nominal value of the temperature
control switch. The electric pulsed heater valve
is then energized depending on the requested quantity
of heat and an electrically-operated water pump
gives a nearly constant water flow for exact temperature
regulation. If the solenoid is not energized, the
coolant circuit to the heat exchanger is fully open. To
control the temperature the solenoid valve is pulsed
by the ATC in periods of four seconds."