Engine Heat

[dalej]

I have always thought this valve is a automatic water diversion valve to allow the engine to heat while the Wabasto is running. It seems to work like a thermostat and open and close according to temperature. I just happen to think that there is no way to make sure it's working properly.

Does anyone know anything about these valves? Not sure If I should replace it since it's 22 years old. Maybe there's a more modern way to divert heated water thru the engine.

[JIM CHALOUPKA]

Maybe if you know what it is supposed to do, you can read the in and out temps, or diverted temps with a dual reading thermalcouple thermometer.
The other way to look at it is if it hasn't seemed to effect the way things work just go on ignoring it.

If you don't know if it's bad how much better can it get. Ignorance is bliss and bliss is real nice sometimes.

JIM

[Yankee802]

Ok, I'm not mechanic or bus guru, but how about taking an infrared thermomater and pointing at the supply hoses, and if the one in question after the juncture is the same temp, it's good?

[garyde]

Hi Dale if it's that old, I'd replace it. It may work today and not tomorrow.

[Jon Wehrenberg]

Continuing the theme that Gary has expressed, since the bus is that old, why not replace it?

[dalej]

I don't know what it's even called, does any know what these are?

[Joe Cannarozzi]

For a photographer that picture is very lacking:D I'm still trying to make sense out of it. In your defence all the plumbing systems I have seen for Webasto are confusing at best.

IMO it would not hurt to keep the loop to the engine open all the time and you believe that is what the device is for? If so leave it alone as long as the engine continues to preheat and if that ever stops simply remove it.

You could replace it with an electrically operated solenoid and give it a switch to control it. CC uses them all over the plumbing systems.

I am not completly convinced your arrows are all correct.

[JIM CHALOUPKA]

OMG, Joe, your getting to talk like Lew:rolleyes:.

JIM

[dalej]

If it's that old, I'd replace it. It may work today and not tomorrow._Gary
Continuing the theme that Gary has expressed, since the bus is that old, why not replace it?_Jon


It I used that rational, I should just replace the whole bus! :)

[dalej]

Lets try it this way, how does your Wabasto heat your engine?

I'm thinking that you flip a switch and a solenoid valve opens and heated coolant runs through your engine.

Mine will be heating the engine even if I don't want it to. Just looking at maybe changing it so I would have more control over it.

I just not sure if keeping the block warm all the time is a good thing.

[Jon Wehrenberg]

I don't know how all the converters and their systems (Webasto, Aquahot, Espar, etc) all are plumbed or how they work, but in our bus we can heat just the engine, just the house, or both. In the compartment where the Webasto is there are numerous valves, plainly marked giving us the option of heating the section we want.

[dalej]

but in our bus we can heat just the engine, just the house, or both. In the compartment where the Webasto is there are numerous valves, plainly marked giving us the option of heating the section we want._Jon

Jon, If you want to pre-heat your engine on a cold day, let's say your dry-camping. You go out in the Wabasto area and turn a valve and then start you Wabasto?

[JIM CHALOUPKA]

Dale IMHO, any time you would want to run the Webasto to heat the bus interior, and the hot water tank, I think it is fine to heat the engine. It will take longer though, meaning more fuel used. If you were dry camping in the north woods that might be important.

On my bus and Jon's you would have to fiddle the valves every time you want it configured differently. I think some are implying that they have a solenoid valve for that. Sounds good, if you want to run different zones at different times.

You make it sound as though yours is automatic. No clue how that works.
Where does the hot water enter the valve and what are the optional flow paths after that time (or when it thermostatically opens) Maybe you have these manual valves too and your device is something extra.

If it's worth it to you take it out of the system and try to test it with boiling water to see if and when anything inside moves. There might be a temp. rating on the housing. In that case a pot of water at that temp. should make the valve move.

If it has a part number try to buy another and see if there are specifications available.

The only bad effect I know of with keeping the engine warm is that it seems to attract rodents to come and nest and have a picnic on your wiring:eek:

JIM

[dalej]

I have a heat zone in the plumbing bay with a thermostat. I have two heat zones in the living area with two thermostats.

If I have my main Wabasto switch at the dash in the on position and the plumbing bay calls for heat then the needed solenoid valves open and heat this bay.

If I want heat in the living area I need to turn on another switch at the dash and then and then when either of the two thermostats call for heat the Wabasto turns on and the proper solenoids open and heats that area.

I do not have anything related to heating he engine except for the item that is in the photo at the start of this thread. I'm only trying to learn more about how the engine is heated in newer units to see if I want to upgrade this area of our bus.

[gmcbuffalo]

Dale, it seems to me that if you shut off the engine loop you will not be heating the water in the Webasto system as you drive down the road, therefore no heat to the water heater or even house registers without the Webasto firing.

I have one of the those in my system also. I will go look at the manual and see if it's use is explained.

GregM

[Joe Cannarozzi]

Based on your current configuration to be able to control your heat to the cabin and the plumbing but not the engine I would assume that the engine is always preheated now and that valve possibly only has the ability to close that engine loop only after it comes up to temp.

I see no downside to always having a heated engine. The extra volume of heated water also gives the burner the ability to go longer between burns.

I am still having a problem figuring out 3 ports on the in questioned device.

[dalej]

I really don't want to shut it off. I like how it's configured. I was just wanting to see how the newer bus's handle the engine heat.

Greg, any info on this little guy would be helpful, I have none.

Joe, the return line is going behind the valve. There is only one line into the valve. Once the water is heated the valve closes off the engine or visa-versa. This is why I'm asking if you guys know anything about how these little guys work.

[gmcbuffalo]

Dale
Here is what I got in the attached file.

It is a diverter. Mine is plumbed different the supply from engine goes in the bottom and comes out the side to the Webasto then the water is off to the registers the return from the registers goes into the top of the diverter and out the top to the engine.

Greg

[dalej]

Greg, I have been looking at the image and there are flows that I can't follow. Can you make some sense of it?

Do you understand what it does or how it works?

[nrhareiner]

Good evening
Dale,

In my present bus, there is a switch that controls a solenoid that allows the engine to be "pre heated". I can run the aquahot with this switch on or off. However, if the aqhahot os off, then even if I press the switch nothing happens. I must have the aquahot on to open the valve. If it is very cold, and I am leaving very early in the AM, I will open the valve before I retire for couple of hours of sleep. If I have a couple of hours after awaking before leaving then I open the valve at that time. I have found that even in very cold weather that 2 hours is sufficient time.

[Ray Davis]

Many of the Marathon's have two solenoid vavles in the engine area. One is normally closed, and one is normally open. If you turn on your heater, the Webasto fires, and by default, the return path does not go through the engine.

If you hit the "Block Heat" switch on the drivers dash (not the block heat in the electrical panel), then these two solenoids are reversed, and return coolant is sent through the engine before returning to the webasto.

It's great IF it works. In my case, and Adam DeGraf's case, the solenoid valves were clogged and not functional causing an issue. (I still have to fix mine). In speaking with Marathon, they are now removing the guts of the two valves, and letting the water cycle in both areas, all the time. Evidently this is what they did for Adam at a recent service in Coburg.

I hope to get some time perhaps this weekend to try to clean the valves, and see if that clears the issue. The solenoid valves are not cheap, and I'd rather not replace, if possible.

Anyway, that's how (some) Marathon's do it.

Ray

[dalej]

The way I'm thinking this valve works is like this. Point A flows to B all the time. There is somthing in the diverter valve that heats up and opens flow from C to D.

Do you guys this this is correct.

[dalej]

Ray, that's what I thought was the case in most newer coachs. I just didn't know if I wanted to go to the work of updating ours to that style.

What I have seems fairly simple, but I have to always have my engine heating. I could put a manual valve in the engine area and just restrict flow when I don't want to heat the engine.

I was also wondering about using the Wabasto to just heat the engine and not the rest of the coach, for the rare times I have been gone and the weather has turned and I need fast heat for the motor.

[Ray Davis]

I was also wondering about using the Wabasto to just heat the engine and not the rest of the coach

On my coach, if you hit the dash block heat, besides reversing the two return solenoids, it also starts the webasto, but does not actuate the valve which runs to the heaters. I do believe there is a manual valve which goes to the water heaters, but it's generally always open.

So, in the case of just trying to heat the engine, it's "supposed" to be a matter of simply turning on block heat, without requesting heat from the inside thermostats.

Ray

[JIM CHALOUPKA]

The way I'm thinking this valve works is like this. Point A flows to B all the time. There is somthing in the diverter valve that heats up and opens flow from C to D.

Do you guys this this is correct.

Dale, I think the valve works this way.

It is for the engine to come to temp. on it's own without the aid of the Webasto.
To get it done in the shortest time, some circuits are shut off until the engine is at temp..

So, looking at your diagram, I think it is C to B until the engine is up to temp.

The valve then opens and it is from C to D and A to B.

The D flow then goes through the Webasto (which is off) through the hot water tank or compartment heater or Summer Winter circuit (options) to heat some or all of them without burning the Webasto.

What do you think?

:cool::)JIM

[gmcbuffalo]

Dale

In the diagram the flow from A to B is a pass thru and I think the flow from C to D is a second pass thru. In my diagram the flow from the engine goes to C and out D to Webasto then to registers back to diverter Port A to B and back to engine. If I shut off the Return and Supply valve on the engine the flow in the system would stop. Therefore I think that the diverter works on pressure and if the flow can't go to the engine then the return flow from the registers is diverter to port D ,since the flow out of B is closed because of the down stream return shut off valve on the engine. Therefore the webasto can keep working with the engine closed off from the system.

GregM

[truk4u]

Dale,

My Liberty is like yours. When the Wabasto is on, everything gets heated. The engine, hot water and all heat exchangers for the house furnace get toasty. There is also a water bay heat exchanger.

Nothing like a 160 degree engine temp when starting on a cold day, no smoke and no missing.

[jimshoen]

Ray,
I believe your coach is likely plumbed up the same as mine. Recently I replaced the two solenoid valves just aft of the Webasto. Additionally I added Y-Type strainers and ball valve shut offs to isolate the valves. There should be three seperate switches in your coach that fire the Webasto. One for engine preheat, another to supply hot coolant to the heat exchangers inside coach, and lastly one to heat domestic hot water. The way Marathon has the system designed is very good but difficult to understand. I have posted on this previously and would be happy to talk with you 775-843-8656.

When you select only the engine preheat (on mine labled System Heat) you will heat both the domestic hot water and the preheat the engine.

When you select only 12 Volt Water Heater you will only heat the domestic hot water. This is nice because it works fast, 20 minutes or less.

When you select only 12 Volt Heat you will heat the domestic hot water and send hot coolant to the heat exchangers in the coach.

Note, that no mater which button you chose you are always heating domestic hot water when the Webasto is running.

Now comes the fun part. What happens when you have more than one button pushed at the the same time.

If 12 Volt Heat and Engine Preheat are selected you will supply hot coolant to the heat exchangers inside coach, preheat engine, and heat domestic hot water. Pushing the 12 Volt Water Heater button along with the two above does nothing additional.

If 12 Volt Heat and 12 Volt Water Heater are selected you will be supplying hot coolant to the heat exchanges inside coach and heating the domestic hot water. 'No engine preheat.'

So what is the big deal? With a 40,000 BTU Webasto and real cold weather we are a little light on BTU's. I have checked this out with OAT's below 10 F.
If the coach is cold soaked and you fire up the Webasto calling for Engine Preheat, Domestic Hot Water and, Coach interior heat you will be waiting a long time to get everything warmed up. So what do I do in these situations.
Ususally I will only call for engine preheat first. Let the Webasto Preheat engine and domestic water only. Now you can start engine and everything is good. Once the engine is preheated switch over the 12 Volt Heat for the interior. If you are plugged in or want to run the generator you can be running the 110 Volt Heat while the engine preheats.
With the engine preheated you have also heated the domestic water. Now we want to heat the interior of the coach asap. Switch over to 12 Volt Heat only and close that manual valve which should be slightly forward and slightly above the Webasto. Now you will have all 40,000 BTU's going into the coach and it will heat up quickly. Hear is the catch, you must make sure to reopen that manual valve before activating anything other that 12 Volt Heat. In any case, the better you understand the system, the more options you have to get what you want when you need it.
I was always curious why the recommendation was to remove the guts from the two controlling valves. Bottom line, few owners want to take the time or energy to understand and maintain this system. In really cold conditions the extra heat inside is very nice especially for the 2000 and older XL's.
When you are driving the bus and want to use the heat from the engine to heat the inside of bus and domestic hot water you need to select both the Engine Preheat (System Heat) and 12 Volt Heat. Then the Webasto only fires the burner when the coolant temperature drops below something like 160F. When ever you select 12 Volt Heat to heat inside coach and you are calling for heat at the thermostat an auxillary coolant circulation pump in the ceiling of the spare tire compartment will be on. This pump assists the Webasto coolant pump in getting the heated coolant all the way to the front of the coach and back. If then auxillary pump is not working you will not get heat inside coach.

[garyde]

So if you remove the solonoids, you have the same heating system as the Libertys. Liberty has gate and ball valves to shut off any one system or all systems. Or, If you don't turn on the T-stats , no heat to the interior. But, I'm not sure what this has to do with
Dale's original post regarding the Thermostat. Dale I'm sure there are new in line mechanical thermostats you can buy and keep it simple.

[jimshoen]

OK, back to Dale's question?
Sorry I have no idea what that is.
Took me two years just to figure out what I have.

[garyde]

If it's that old, I'd replace it. It may work today and not tomorrow._Gary
Continuing the theme that Gary has expressed, since the bus is that old, why not replace it?_Jon


It I used that rational, I should just replace the whole bus! :)


Hi Dale. Slowly but surely, isn't that were doing? :D

[gmcbuffalo]

Dale

I don't think it is thermastatical controlled. I think it has a spring and a pressure plate inside. As you can see in my schematic the only way water could get to the Webasto with the return shut off ball valve closed is if something opens up in that "can"

GregM

[Yankee802]

I'm not sure how mine works, other than when either I manually turn on the Webasto or the thermostat inside does, it heats the inside of the coach. I don't know if it heats the engine or not, never thought to check. The previous owner pointed out a valve in the engine compartment on the driver's side near the firewall (I think it's a firewall). He said it had something to do with the Webasto, but he never touched it. Maybe it controls whether or not the engine gets heat?

While we on the subject, I (of course) have a couple questions.

I thought it was antifreeze that is heated and circulated by the Webasto, is it water?

In my bedroom closet there is what looks like a resovior of sorts, with the same kind of cap found on older radiators. I can hear it kinda gurgle when the Webasto is on, and the tank/resovior gets HOT to the touch. Any one else have anything like this? Is the gurgle normal? I guess I should open up the cap one day (obviously when it's cold) and take a peek inside. :)

[gmcbuffalo]

yes it is coolant tha tis circulated.

No idea on your closet tank.

GregM

[truk4u]

Geoff,

Webasto uses the engine coolant, Aqua Hot is a closed system that uses it's own anti-freeze and has a storage tank. Not sure what you have, the Aqua Hot tanks are usually in a bay with the burner unit.

Due the age of yours, are you sure you don't have Espar Heaters?

[Yankee802]

I'm not positive about the whole system, but the burner unit is definately Webasto.