Webasto heater?

[Jpav]

I have been looking at these webasto heaters and I am very interested. I was wandering if anybody had any info they would be willing to share. I have a Thomas diesel powered short bus and I live on the coast of Washington were winter temperature gets down to about 20 degrees on the coldest nights. My bus still has all its Windows ( four rows of windows) and still has the original insulation. I would like to be able to run it for about 20 hours before recharging my house batteries and I am not planning to use solar(at least at first) so my house batteries would just have to charge wen the engine is running. I have some questions and hope that some people who are more knowledgeable than me could answer them. How many Btu's do I need? How many amp hours do I need. What kind of maintenance dose this heater require?is there any common problems? How much fuel dose it use? Iknow that its not black and white and that there are many variables that come into play but if i could just get pointed in the right direction that would be great. If anybody can think of any questions i didnt ask and should have please tell me. Any replyys would be greatly appreciate, thanks.

[cadillackid]

I think the webasto web site can help you with some of the questions.. if you are going with a coolant heater, then I would set up a loop where you can include or exclude the engine coolant loops.. ie if you arent going to be driving the bus for a time, you can heat coolant only circulating inside the bus.. this will help. get the heat where you need..

Joeblack5 uses one to heat his similar short bus nicely.. he swapped to computer fans for one of his heater cores as that reduced the electricity required and noise of the fan to heat his bus (Genius!).

the webasto site can give you the number of gallons per hour of fuel the webasto requires as well as the amps it opulls to operate.

I would also add that to me, a smart move is to pipe it in separately to the fuel tank.. and plasce the fuel pickup of the heater higher than that of the engine fuel.. thus you wont run your nbus out of fuel with the heater, and are much more unlikely to pick up any dirt that could possibly clog the nozzle.. make sure you install a fuel filter in the fuel line for that heater.. thats important towards longevity of it..
-Christopher

[ThunderstruckStudios]

Jpav,

I can help with how many BTUs you need...how long is your bus and what sort of insulation do you have? The more details the better.

[Beachvbguy]

I've checked out the heaters and they look pretty good. Has anyone had any success using them to replace the main driver's heating and defrosting system?
I have a 2004 Thomas Saf-T-Liner, and with the modifications I have planned, re-routing that heating hose all the way from the back just to run the driver's heat and, more importantly, to defrost those huge windows, is something I would love to avoid, if possible.

[cadillackid]

there are different models.. the driver and door heaters in most busses are 100,000 BTU each.. if you are super insulating your bus you dont likely need that much heat to defrost.. however a pain to run the hoses, it seems counter productive to burn diesel fuel separately to defrost while wasting the engine heat out the radiator..



the other benefit of a webasto heater is that if you park your bus on a very cold night someplace it can be used to heat the engine. warm-starting a diesel engine is much easier on the starter and the engine vs cold starting it..



I installed a webasto on my red bus.. I turn it on an hour before i start the bus and it fires up easy and I have heat right away.. sometimes i leave it on when im parked for a few hours.. I get back in.. turn on the engine and bam heat right away..



not to mention the oil and coolant are pre-warmed and circulating right away..

[Beachvbguy]

Originally Posted by cadillackid

there are different models.. the driver and door heaters in most busses are 100,000 BTU each.. if you are super insulating your bus you dont likely need that much heat to defrost.. however a pain to run the hoses, it seems counter productive to burn diesel fuel separately to defrost while wasting the engine heat out the radiator..



the other benefit of a webasto heater is that if you park your bus on a very cold night someplace it can be used to heat the engine. warm-starting a diesel engine is much easier on the starter and the engine vs cold starting it..



I installed a webasto on my red bus.. I turn it on an hour before i start the bus and it fires up easy and I have heat right away.. sometimes i leave it on when im parked for a few hours.. I get back in.. turn on the engine and bam heat right away..



not to mention the oil and coolant are pre-warmed and circulating right away..

Ok. My issue is that I won't be using the room heater from the bus, and I'm going to make the emergency exit my main door, so I have to re-route the hoses all the way from back to front just to run the driver heat and defroster. I know it can be done, but looking at all alternatives.

[Oscar1]

Originally Posted by Beachvbguy

Ok. My issue is that I won't be using the room heater from the bus, and I'm going to make the emergency exit my main door, so I have to re-route the hoses all the way from back to front just to run the driver heat and defroster. I know it can be done, but looking at all alternatives.

If you don't need it plumbed in to the engine coolant Espar makes a forced air unit. I have one that I installed in the uninsulated cab of my work boat and it keeps things nice and comfy all winter. I used a portable outboard fuel tank for diesel. Search for Espar D2 for specs. They are very costly. Recently there have been many Chinese clones for sale at a very good price on Amazon receiving good reviews.

[magnakansas]

If you are going to keep the front heat, there is no need to run hoses to the back and back again..... engine to heater then heater back to engine .... bringing hoses from the front to the back is not needed if you are not connecting a heater back there.

william

[Beachvbguy]

Originally Posted by magnakansas

If you are going to keep the front heat, there is no need to run hoses to the back and back again..... engine to heater then heater back to engine .... bringing hoses from the front to the back is not needed if you are not connecting a heater back there.

william

William,
If I don't run the hoses from the rear engine to the front, I can't use the heat from the engine to heat the driver's area and, most importantly, to keep the very large windows defrosted. That's the whole point. I'm not concerned with heating the living space, I have multiple options (and probably two dogs) to handle that requirement.

[Beirdo]

Originally Posted by cadillackid

the other benefit of a webasto heater is that if you park your bus on a very cold night someplace it can be used to heat the engine. warm-starting a diesel engine is much easier on the starter and the engine vs cold starting it..



I installed a webasto on my red bus.. I turn it on an hour before i start the bus and it fires up easy and I have heat right away.. sometimes i leave it on when im parked for a few hours.. I get back in.. turn on the engine and bam heat right away..



not to mention the oil and coolant are pre-warmed and circulating right away..

I realize this was months ago (first off)... However... Do you know of somewhere to source a used webasto coolant heater from (not the air one)? I'm thinking I might want to put one in so I can pre-heat the coolant when it's mighty cold out... it could also be useful to reuse the heater block in the back of the bus (with some interesting valves, probably - bypass the block in that use case).

Are these possibly found in junkyards on busted vehicles, and if so, any particular ones to look for here on the North America side of the pond? Everything I'm seeing online is Europe-centric, which makes sense given the much higher ratio of diesels over there. I hesitate to think of having to ship a used one from Russia or something silly like that if they are actually to be found here.

[Sehnsucht]

Later model Freightliner Cascadia semi trucks use the coolant linked bunker heater which warms the engine coolant at the same time as providing bunk heating comfort m. I'm not sure if you're looking for the air warming function but seems to me couldn't hurt. Also not sure if you'll still need controls as Freightliner tied all of these systems together with its ParkSmart system so the bunk heater is controlled by the truck's electronics and not simply a standalone control stuck on the wall.

[cadillackid]

I see these webasto heaters all the time on northern school busses.. some of the wrecking yards pull them, others dont. there are also chinese coolant heaters showing up now too.. alot depends on how much heat you want. my red bus has a 5kw webasto in it and it does an OK joib of heating my stock 6 window shorty bus inside as long as its not too cold out.. of course its wonderful at being a coolant preheater so if ther bus is parked overnight not plugged in (Ive had it in -15f) then letting that run for even just 30 minutes or so makjes a Huge difference in starting the bus..



in my DEV bus I have the VVKB 12kw coolant heater.. ive only had it a few months.. but so far it has kept me quite toasty inside my 7 window 30-year-old stock bus (down into the low 20s)..


by stock interiors i mean my busses have all their original floors, doors, windows, walls, and ceilings.. noi added insulation and no window coverings.. they are still very much busses.



Now lets talk fancy valves and cabin heating.. its not as simple as that.. I re-learned what I already knew from my HVAC days in hydronics.. you cant simply close your bus heater valves and reun your coolant heater through the cabin heaters only.. well you can but its not ideal and can be risky..



there asre many ways to pipe these heaters into your bus. in my carpenter the factory heating system loops are parallel flow measning there are 2 main 1 inch trunks going through the bus and each heater has 2 take-offs from the mains.. a supply and return.

the rear heater is the end of the line and the original unit had a crimp in the line to increase the supply pressure through the trunks.. a system like this relies on the fact the water pumps in operation can produce enough pressure on the supply trunk and enough vacuum on the return trunk to push wateer through all the heater cores.. and it works.



I have a pair of electric valves under the hood which can be closed or opened by switch on the dash to kill the flow to the indoor heating system and isolate it from the engine. if i plug my electric block heater in at night, it strictly heats the engine for easy starting as the valves close when they lose power.



my plan was to pipe my 12kw heater into the cabin heater loops and leave the valves closed when I wantedto heat the bus inside (its my mobile office, dining-room, etc) but not heat the engine.. however the issue arises that without expansion and contraction capabilities the coolant system either expands through slight leakage in the valves, but then when it contracts it is short of water.. so a cold heater startup resulted in the heater detecting it had low water and shut off or never fired at all.



noine of these centrigual style heater pumps are self priming.. if they run dry they are done... they have ZERO capability to suck a prime.



fortunately the computer in my VVKB heater is smart enough to turn off and not burn the heater up.. ive heard of some of the chinese units actually running to oblivion or damage in the case of liow water..



what ive had to do to fix it is add an aux pump to help keep things flowing, and also added an additional expansion tank a small one that is in the heater loops.. this way when the bus is being driven with the valves open and heat on it fills that tank to some extent.. when i park and the bus cools off it uses that coolant to keep the heater loops full.. when i turn on the heater to heat the bus interior then that tank takes the expansion.. this ensures i have coolant in the loops at all times and can leave the valves closed so i dont have to heat the engine while im parked if i dont want to.. when i do i flio the switch, open the valves and keep the engine warm..



-Christopher

[Native]

Thank you Chris. I am currently designing our heating system and would like to do much the same as you have done


Placement: From the engine after the valves, do you have the coolant heater, then the pump, then expansion tank, then heater loops?


Where are the feedback loops for when the valves are closed an you want to circulate within the bus cabin?


Do you have a sketch (functional flow diagram) of your components?

[Beirdo]

Originally Posted by cadillackid

I see these webasto heaters all the time on northern school busses.. some of the wrecking yards pull them, others dont. there are also chinese coolant heaters showing up now too.. alot depends on how much heat you want. my red bus has a 5kw webasto in it and it does an OK joib of heating my stock 6 window shorty bus inside as long as its not too cold out.. of course its wonderful at being a coolant preheater so if ther bus is parked overnight not plugged in (Ive had it in -15f) then letting that run for even just 30 minutes or so makjes a Huge difference in starting the bus..

Thanks. Yeah, strangely enough, I'm more "northern" than most of the USA, but the weather here isn't so cold most of the time. I'll see if I can't find somewhere out in Minnesota or something to get a used coolant heater from, I guess. Definitely better than shipping from Europe!

Originally Posted by cadillackid

in my DEV bus I have the VVKB 12kw coolant heater.. ive only had it a few months.. but so far it has kept me quite toasty inside my 7 window 30-year-old stock bus (down into the low 20s)..

I will take a look at those as well. I think the Webasto ones should be good for engine heating, but yeah, for bus heater use, I might want something a bit beefier.

Originally Posted by cadillackid

what ive had to do to fix it is add an aux pump to help keep things flowing, and also added an additional expansion tank a small one that is in the heater loops.. this way when the bus is being driven with the valves open and heat on it fills that tank to some extent.. when i park and the bus cools off it uses that coolant to keep the heater loops full.. when i turn on the heater to heat the bus interior then that tank takes the expansion.. this ensures i have coolant in the loops at all times and can leave the valves closed so i dont have to heat the engine while im parked if i dont want to.. when i do i flio the switch, open the valves and keep the engine warm..

Hmmm, very good points raised there. So essentially if I want to have it switchable to exclude or include the cabin heater(s), then I have to treat it like a hot water heater boiler system. That makes sense to me. I'll come up with a diagram of what I'm thinking in the next few days, and run it by you. Someone with your knowledge is much appreciated, thanks You probably saved several of us some painful experiences that you've already learned from.

[Beirdo]

Well, happy birthday to me!

I found a Webasto Thermo Top C at a truck wrecker in Iowa (www.vanderhaags.com) that was on a 2015 Kenworth T680. I say "was" because I bought it, and it has been shipped. It is scheduled for delivery on my birthday (next Tuesday).

I have a new cable loom for it on its way from the UK (an ebay buy) and also a new controller frontend on its way from the UK (also ebay).

Hopefully, I'll be able to get it all hooked up relatively soon.

The Eberspacher Heater Hydronic D5WS Technical Manual shows several ways to hook this type of unit up if you want to go past the simple methodology (yes, I know, it's a competing product, but they are fairly similar). I think to start with, I will probably just do the simple installation: engine -> pump -> preheater -> heater (heat exchanger) -> engine.

For reference (in case you guys want to find them), the manuals are all online at www.butlertechnick.com - which is a UK-based distributor of both Webasto and Eberspacher products.

I am also planning to do a custom diagnostics setup, hooking up the K-line diagnostics line to a custom converter I'm building (which does K-line -> UART -> USB), and plugging that into a Raspberry Pi and writing my own control and monitoring software for it. With the controller, I don't NEED it, but I do need to geek out. If anyone is interested in getting a diagnostics converter board for their heater(s), let me know. I don't know total cost yet, but it is a tiny board, and cheap-ish components, so I doubt the build cost will be much at all. If they work well, and my software does well, I probably will go sell some on ebay too, but you guys get the "skoolie" price should I build them out - i.e. cost.

[cadillackid]

Which thermobtop did you get? Tsl-17? I prob have the install book to mine still, I had bought it new cheap from a boat place going out of business.

The vvkb I have in the other bus I’m building a diagnostic control for it that will connect into the rpi 4 already getting set up for the bus.
I love these kinds of projects, what is k line? I haven’t yet tried to crack the protocol coming from mine yet however a first analysis makes it look like similar to the single wire that the minisplits use which I cracked way back in 09.
If there’s already info on heater protocols I’d rather read that then go through cracking it. Of course my vvkb and webasto may use different protocols.

I piped mine in such a way on the dev bus to be able to heat only the cabin or can heat cabin and engine both. It ended up being pretty complex to get it to work , requiring an expansion tank on the cabin side, thus far it works but we shall see if I end up with coolant transfer such that my indoor tank goes empty, the setup is new, but I wanted the ability to hang out in my bus with just the bus heaters hot but also to be able to preheat the engine if I chose . I already had electric valves which isolate the bus heaters from engine .

My red bus with the tsl17 the engine is always in the loop on that one. I’m not using the webasto controller on it, that heater is started by a switch for now,

Both of my heaters can be turned on / off by 12 volts being sent to their ON or active wire.

[Beirdo]

Originally Posted by cadillackid

Which thermobtop did you get? Tsl-17? I prob have the install book to mine still, I had bought it new cheap from a boat place going out of business.

This is the exact image I have from their site. (I forgot to save the other with JUST the label!):


It's a Thermo Top C - Diesel. That doesn't get us the exact model number, though. I believe I have the manual downloaded (from the same UK site), but I'll check.

Originally Posted by cadillackid

The vvkb I have in the other bus I’m building a diagnostic control for it that will connect into the rpi 4 already getting set up for the bus.
I love these kinds of projects, what is k line? I haven’t yet tried to crack the protocol coming from mine yet however a first analysis makes it look like similar to the single wire that the minisplits use which I cracked way back in 09.
If there’s already info on heater protocols I’d rather read that then go through cracking it. Of course my vvkb and webasto may use different protocols.

I love these projects too K-Line refers to the ISO-9141 diagnostics line (that is also often routed to the OBD-II port). The base line protocol seems to be 12V at idle, and then 12V for on, 0V for of... and essentially UART protocol pn top of that carrying the data frames. That's how far I've gotten so far. My interface board is designed around using the STMicro L9637 chip to convert it to CMOS/TTL level UART Rx/Tx, which I then am feeding to a FTDI FT230 chip to get it to appear as a USB UART.

After that the rest of the magic is just software on the RPi (or any other Linux box, really). Software I will need to write still, but there is a "libwbus" that purports to give Webasto support for Arduino, so I'll be using that as a starting point.

I would not be surprised if the VVKB also used the K-Line part, although the top-level control data may be different in the end.

Originally Posted by cadillackid

I piped mine in such a way on the dev bus to be able to heat only the cabin or can heat cabin and engine both. It ended up being pretty complex to get it to work , requiring an expansion tank on the cabin side, thus far it works but we shall see if I end up with coolant transfer such that my indoor tank goes empty, the setup is new, but I wanted the ability to hang out in my bus with just the bus heaters hot but also to be able to preheat the engine if I chose . I already had electric valves which isolate the bus heaters from engine .

Yeah, going to take a much better look at the setups that Espar Hydronics manual has in it before I decide on a final design, but it will likely be similar to that, and I may also add a heat exchanger for hot water heater rather than adding a separate unit. Haven't really decided on that either. I have a few days If I do put in electric valves, I'm sure I'll have them controlled from the RPi too. I can use the 3 of the 4 IOs on the FT230 for something more useful than LEDs... the other is used to sense VBUS from the USB. No reason I can't have those GPIO drive a relay that opens/closes the valve (well depending on valve design of course). I can make it work.

Originally Posted by cadillackid

My red bus with the tsl17 the engine is always in the loop on that one. I’m not using the webasto controller on it, that heater is started by a switch for now,

Both of my heaters can be turned on / off by 12 volts being sent to their ON or active wire.

Yeah, I think this one probably can too. However, I kinda have my eyes on the "cheap" BMW and LandRover pulls in Europe. If I can make a viable controller that can control those or mine, etc... I think there could be a good market for decent diesel-powered coolant heaters in the skoolie community... if the price were right.

But yeah, my electrical engineering degree needs to be good for something, and I love tinkering with circuit design. I want to have all the diagnostics (and telemetry data overall) in a running database on a small (whatever that means in the end) Linux box that I'll put up above the driver seat along with a security DVR for backup/side/dash cams... And then use an Android tablet as my at-dash display... and probably something hooked up to the TV as well for a larger display.

Oh, yes, I'm geeking out.

[Beirdo]

I'm actually considering adding a full OBD-II -> USB setup rather than using bluetooth for OBD-II, BTW.

[Native]

Originally Posted by cadillackid

It ended up being pretty complex to get it to work , requiring an expansion tank on the cabin side, thus far it works but we shall see if I end up with coolant transfer such that my indoor tank goes empty

I am having a difficult time locating an expansion tank (looking for a bladder tank) that is rated in excess of 200 degrees (F).


Where did you get yours?


What type?


How much?

[Beirdo]

I'm looking at the pressure expansion tanks (6.3gal size) on Home Depot's site (search for hot water expansion tank). I know that may not be precisely what you had in mind, but... rated 210F.

Worth a look anyways, right?