The compact and well-proven Webasto TSL-17, 17000btu Water heater kit pre-heats the cabin interior and the circulating engine coolant to optimal start-up temperature. The stress on the engine through coldstarts is thereby drastically reduced, whilst the longevity and operational readiness of the engine is substantially increased. If you are a Webasto dealer looking for product specific technical information. MultiControl Operation Manual. Last Updated: 11 February, 2019.

School Bus Fleet Magazine Forums Webasto coolaant heaters. Author Topic Advanced Member 274 Posts Posted -: 06:14:15 AM Last year all 6 of our new CE's which came with the Maxxforce 7 engines had Webasto coolant heaters on them so they could keep up in the cold wisconsin winter.

Now that the winter is almost over not one of them is still working. Some spit fuel out the exhaust pipe, some make a clicking niose in the control panel. We sent one over to the dealer and they couldnt fix it and said to bring it back when they had more time to diagnose it. I just download the service manual and was wondering if any of you who have had training and have done maintenence on these units can give me the common fixes and tips for diagnosing the issues. It looks like there is a special tool from webasto that can run the unit. Is it needed and what does it do?

We installed winter fronts on the busses and that helped a little. Thanks Senior Member USA 114 Posts Posted -: 08:37:48 AM Webasto has a good tech line if you call them direct or if you'd rather feel free to call us. Our website is We sell and service a ton of them in all sizes on mostly Thomas but a lot of IC and BB and trucks too (even lobster boats, equipment and pretty much anything w/diesel).

They are a great product but they do take some work. My email address and our parts and service guys are on there or feel free to call. They sell a test box for the Scholastic 45000 BTU heaters. The small ones require software (free download from Webasto) and a cable which you have to buy that connects your USB to the heater. Top Member USA 2181 Posts Posted -: 06:26:31 AM Wow those things have advanced. Sounds interesting, I'll check it out.

We sold a few Birds up north with the Webasto back in 2006 or 07 I think. They do a hell of a job I'm told.

“The good thing about science is that it's true whether or not you believe in it.” Neil deGrasse Tyson Advanced Member USA 398 Posts Posted -: 07:16:09 AM The right tooling makes all the difference. If your unit is a Scholastic large yellow the test box replaces the electronic control box and lets you test every thing manually. The tsl 17 is small silver and mounted on the frame or battery box, it uses the laptop software.The most common problem on the large heater is the inertia switch, red rubber covered button up front in the box. Just push on the center of the button and see if the unit will now heat up.

There is also a fuse holder 3 ATM fuses in a black plastic covered holder at the rear right side of the unit. Senior Member USA 114 Posts Posted -: 08:29:13 AM We built a rolling test stand with a cart, couple extra batteries and a water inlet/outlet and loop w/expansion tank. There's a spot to bolt on both scholastics or TSL's to bench test.

It sure doesn't look attractive but it works, and man.does it melt snowbanks when you point the hot water outlet the right way. Top Member 533 Posts Posted -: 09:55:31 AM quote: Originally posted by bcressey and man.does it melt snowbanks when you point the hot water outlet the right way. It sounds like you dealers are having a little too much fun.

ToriBell 11.11.16 15:31 comment3, chity_na_blokadu. Osmotr anesteziologa blank.

Advanced Member 274 Posts Posted -: 1:16:02 PM Thanks for the tips. The drivers loved them when they worked. These units are the yellow ones with the silver box mounted on them.