Getting cold - need heat

[windtrader]

Back to BCM busnut topics.

One of the last systems I've not figured out is the Webasto heating system. There is plenty of documentation but there is some mental block that keeps the light from going on.

In the coach, there is a panel that has two switches: One says Engine preheat pump on/off, the other says burner/exchanger/off.

In the heater bay, there are pipes and valves running everywhere. The diagrams help sort out where they go and what the valves control.

Here is what I think I need to do.
1) Open the valves on the pipes going to the MSR fan heaters in the coach and bays.
2) Open valve leaving Webasto DBW300 and leading to manifold that connects pipes to fan heaters
3) Find expansion tank and check fluid level
4) Turn up theromstats.
5) Flip switch to burner

Check if pump starts up, burner lights up, and feel for heat in the pipes.

Here is a couple images;
coach heater switch panel - https://www.dropbox.com/s/iiwlx87b5n69vsh/IMG_20171212_163830.jpg?dl=0
Webasto DBW300 heater and pump - https://www.dropbox.com/s/mhs12wqigk477rh/IMG_20171212_163939.jpg?dl=0
Pipes and valves - https://www.dropbox.com/s/q23ebqur3pk6mxe/IMG_20171212_163945.jpg?dl=0
Heater plumbing diagram https://www.dropbox.com/s/h0bhsadltt2t2sc/IMG_20171215_181709.jpg?dl=0
another diagram - https://www.dropbox.com/s/6qoy7pwrrvm0blc/IMG_20171215_193425.jpg?dl=0

Other configurations I can deal with later such as loops pushing webasto heat thru the fresh water heater and the 8v71 heat exchanger. Not even sure if it is designed so the engine heats the coach or the webasto is supposed to heat the motor via the exchanger. LOL

[eagle19952]

A webasto is not a system that i consider a reliable heat source.

[gumpy]

I appears that your pump is on the return side of the system. Probably ok, but not my choice, though I understand why they did it this way. Also looks like you have two gate valves on the supply and return. Both will need to be opened.

You're steps seem reasonable.

The heat exchanger seems to have a pump on it. I would assume that is an engine preheat pump. You probably don't need that while driving. If plumbed to the engine correctly, the engine should circulate through the exchanger loop while driving and you should be able to neat the domestic water with that. Probably need to circ pump on, though as the exchanger is a closed system with the engine. I doubt that heat exchanger will be big enough to heat the coach off the engine. You'll need to use coach heat or run the Webasto while driving to heat the coach.

Can't really tell where that 3-way valve goes. Seems to be cut off on the bottom of the schematic.

[Iceni John]

If plumbed to the engine correctly, the engine should circulate through the exchanger loop while driving . . .

Is that from the 1"-threaded outlet on the driver-side thermostat housing on a 6V92?

John

[gumpy]

Is that from the 1"-threaded outlet on the driver-side thermostat housing on a 6V92?

John

That would probably work well.

On mine, I tapped into an existing line coming out of the block on the passenger side. Might be the air compressor coolant line. Don't recall offhand. The return goes into the coach heat return line next to the mounting rails in the MC9. Works fine. Obviously it's going to be the hottest.

I've seen them tapped into the coach heat lines inside the tunnel, but that was too confined for me to feel comfortable cutting and soldering in there.

[Jon]

A webasto is not a system that i consider a reliable heat source.

I would have to disagree. Like any other device a Webasto needs maintenance. From the experience of hundreds if not thousands of conversions with a Webasto or Espar or Hurricane system these diesel powered heat exchangers are reliable and fuel efficient. All of them however require exercising on a regular basis because the most likely trouble spot is the nozzle that gets plugged from the waxy substances in fuel if not used routinely.

There are other items that may occasionally need attention such as cleaning the electronic "eye" or making sure the points for the igniter are set correctly but generally speaking Webasto and other similar heaters are pretty reliable.

[luvrbus]

Your 1st time use have someone tune the system and walk you through how the system works money well spent IMO

[sledhead]

nice looking set up . with mine I just turn on the boiler switch and set the thermostats and all is good + it heats the hot water

I agree about getting someone with experience walk you through the set up

dave

[Oonrahnjay]

nice looking set up . with mine I just turn on the boiler switch and set the thermostats and all is good + it heats the hot water ...
dave

     Do you also have a way to transfer heat to the engine block for engine preheating, Dave?  IWSTM that that's pretty much a perfect home run for a heat source.  Also, a system set up like that should give you OTR heat in the coach and "endless/free" hot water (from engine coolant).

[richard5933]

We had a nearly identical setup on our previous coach. It had not been run in some time and needed maintenance. I finally admitted defeat and sent it to Lloyd De Gerald, who is a trained tech on these units. He went through the unit, cleaned it and did maintenance, and sent it back quickly. Best money I spent getting the heating working again in the coach. He's got the test unit for the Webasto control box so he can confirm that everything is working properly. Send me a PM and I'll forward you his contact information. Lloyd will also walk you through the steps to be sure that the Webasto is getting proper power in the proper places.

When working properly the unit should make enough heat to keep you toasty. Whether you run it while on the road depends on whether or not your OTR (factory) heat is still in place. If it is still there then you won't need to use the Webasto while on the road.

The engine preheat is used only when you want to get the DD warmed and ready to start. One ours the Webasto heat was not sent to the engine unless the switch is flipped. Otherwise, you'll be throwing your heat overboard and out the back of the bus needlessly. On ours, the engine pre-heat switch turned on a secondary pump which diverted the heated fluid through the loop going to the engine. Looks like yours might use a valve to open the engine heat exchange loop.

You can also check your thermostat to be sure that it's functioning properly, as that can cause the whole works to stall. Same with the two main fuses that power the Webasto.

[luvrbus]

There is dozen of ways to skin the cat on those heating systems I have seen neat installs by owners with no valves and I have seen some cobbled up systems with valves and pumps.Parts for those are expensive and you can screw one up if not careful because they are touchy lol I have 2 units laying in the shop now owners have screwed up   

[opus]

A webasto is not a system that i consider a reliable heat source.

Disagree, I use mine constantly.  However, if you arent a master at maintaining things, look somewhere else.  You have to stay on top of these or else they get expensive to fix.

[luvrbus]

Disagree, I use mine constantly.  However, if you arent a master at maintaining things, look somewhere else.  You have to stay on top of these or else they get expensive to fix.

They are expensive for parts the board for 1 was over 400 bucks and the coil was 500 bucks 24v on a 12v system is not all that good   

[eagle19952]

OK. rephrase. There are better options.

[Jon]

What are those options. I have had heat pumps, propane furnaces, electric heaters etc. but hands down Webasto is the most efficient, can heat the engine also, and over the last 13 years has been reliable.

Hard to beat so I am curious as to what you think might be a better choice.