Country Coach specific question engine preheat

[gnvrvin]

Hi for those of us that have hydronic heating systems that can perform engine preheat functions.
The fluid being heated must be engine coolant yes? That his heated in our hydronic systems?
And the reverse is true when traveling and no hydronic system on but engine preheat pump is circulating we can run our furnaces when traveling in cold weather?
So the fluid in the heat exchangers for the furnace must be engine coolant? Correct?

Thanks
Greg

[Chargerman]

The engine coolant and boiler fluid are separate. The engine coolant is circulated through the furnace on a loop that is separate from the units hydronic fluid.

[BillJinOR]

The engine coolant is separate. The preheat pump is only used with the engine off to circulate coolant in the engine through the boiler. This heats the engine assuming the boiler is on. If the engine is running its own coolant pump circulates engine coolant to the boiler by itself and ends up heating the boiler , no need for the boiler to be on while traveling. ( preheat pump should be off as it’s not needed)

[Gatesway]

Since the fluid is different than the engine coolant and it is in close proximity to the potable water (inside the hydronic heater), we use a non-toxic coolant. If there were ever a leak in the heat exchanger, coolant would be combined with the potable water.

This was told to us by the previous owner...

I'll attach a picture.

[gnvrvin]

Originally Posted by BillJinOR

The engine coolant is separate. The preheat pump is only used with the engine off to circulate coolant in the engine through the boiler. This heats the engine assuming the boiler is on. If the engine is running its own coolant pump circulates engine coolant to the boiler by itself and ends up heating the boiler , no need for the boiler to be on while traveling. ( preheat pump should be off as it’s not needed)

Thanks Bill
Makes sense about not needing engine preheat on during travel..water pump on engine does that chore

And as it's engine coolant the only boiler fluid is in the hydrohot boiler tank...thus the use of GRAS boiler fluid

Greg

[IASM]

The boiler hold a few gallons and is basicly a water tank heated by the diesel or electric elements. There are two heating coils running thru the boiler tank. One running clean tap water and one running engine coolant. The boiler tank can either heat the engine coolant or the engine coolant can heat the boiler tank. It just depends on which one is hot or cold.
The boiler tank is filled with boiler antifreez and the water is sent to the individual radiators or ex-changers .

[gnvrvin]

IASM
Our Hydrohot only uses one element and it's not large..and also needs to be replaced that's why nI need to drain and since I don't know the age of boiler fluid going to do a swap out
Also as you said boiler heats engine coolant..that was all swapped out 3 years ago that fluid also supplies hot fluid to heat exchangers for the furnace
The other coil is just for hot water

Oh and howdy neighbor!
Greg

[dogpaddle]

Originally Posted by gnvrvin

Hi for those of us that have hydronic heating systems that can perform engine preheat functions.
The fluid being heated must be engine coolant yes? That his heated in our hydronic systems?
And the reverse is true when traveling and no hydronic system on but engine preheat pump is circulating we can run our furnaces when traveling in cold weather?
So the fluid in the heat exchangers for the furnace must be engine coolant? Correct?

Thanks
Greg

on my 2006 Affinity I also have another pump that is in the cooling system it is a MP29224 Straight port pump. It is located under the coach by the rare axle. This pump developed a leak that came from the weep hole and leaked Engine coolant.
Apparently it circulates the coolant to parts unknown in the front of the coach. Can someone explain to me what the purpose of that pump is? And what controls it?
Thanks

[gnvrvin]

OK I have come.to find out that it is indeed boiler fluid that is used in for heat exchangers to heat interior of coach...just recently drained and flushed loop 1 and loop.2
Engine coolant runs through a seperate coil to heat boiler fluid during travel and boiler does not to be on. When it's cold.fire boiler off and turn on engine preheat to circulate the heated engine coolant to warm engine
If the engine coolant coil leaks it will not make its way into the potable water but will Leake into your boiler tank...causing overflow
Potable water runs through a seperate coil to be heated. Most water supplie are higher than the max pressure of 13 PsI that allowed in our hydrohot...hence 13PSI pressure cap. So highly unlikely of cross contamination
Rebuilt unit on the way hope tone ready to drop it in place day of arrival
Greg

[BonS]

Originally Posted by dogpaddle

on my 2006 Affinity I also have another pump that is in the cooling system it is a MP29224 Straight port pump. It is located under the coach by the rare axle. This pump developed a leak that came from the weep hole and leaked Engine coolant.
Apparently it circulates the coolant to parts unknown in the front of the coach. Can someone explain to me what the purpose of that pump is? And what controls it?
Thanks

No direct knowledge but I believe that pump is for the front heater core to augment flow. I've also read that some just remove the pump and patch the hose back together.

[gnvrvin]

Originally Posted by BonS

No direct knowledge but I believe that pump is for the front heater core to augment flow. I've also read that some just remove the pump and patch the hose back together.

Bingo...heard the same as they are prone to catastrophic failure expelling engine coolant fluid

Do a search there have been a few posts ont it

Good Call BonS
Greg