Webasto Thermo Top T: Water Pump Replacement & Leaks?

Hello,
'My Webasto BW50 stopped working. After reading the error memory, the Bosch service determined that the water pump has a short circuit. Apparently, the water pump design of the heater has a known flaw, so that a vacuum is created when the cooling system heats up and cools down, which eventually affects the pump. Therefore, Webasto offers a retrofit kit, a pump with a small hose attached that equalizes the pressure. This requires drilling a 5mm hole in the housing, but it is all described in detail. The circulation pump also cost €167 at the Bosch service!'
I took some photos of the installation process. If anyone else has the same problem, I can put the photos online.

But I have a problem: The ceramic lining in the combustion chamber has crumbled, and now the heater won't ignite. According to the Webasto hotline, the ceramic lining is not available separately, only the entire burner unit (approximately 70€) --> does anyone know of a cheaper alternative?

Is this tile available for individual purchase?
Can an alternative material be used instead?
3. What is the function of the smaller probe in the combustion chamber? The larger one glows, but the smaller one doesn't. Is the smaller one also defective, or does it only measure temperature, or something like that?


Thank you very much.

Heating system data: Thermo Top T (BW50) model year 1998, >300000 [/b].

Hi,
I also have a Top T... but for diesel engines.
Fortunately, the problem with the circulation pump hasn't occurred in mine yet, even after about 6 years (thankfully, because of the annoying cost of replacing it). But I recently dealt with the issue of the crumbling tile. Your price seems reasonable.
I can't imagine there's a cheaper alternative. I have absolutely no idea what material could be used to replace the tile. It also needs to be durable and, moreover, it needs to...function...properly.
If the tile is available individually... actually, that's a good question!
Then it would also be interesting to know how to permanently attach it.

Regarding the pens:
One of the two pins (the thicker one) is the ignition pin, and the other (the thinner one) is the flame sensor. If the flame unexpectedly goes out, the heating system shuts off. That's actually a good thing... hehe.

Here's a small tip for replacing the burner insert (the part with the filter):
There are two types of control units: one with external ventilation and one with internal ventilation. The internal ventilation consists of a small rubber hose connecting the burner cover to the burner insert, which leads into the control unit. Under no circumstances should this hose be accidentally or intentionally removed. This is indicated in the workshop manual. The reason for this is unknown to me. However, I believe that it is difficult to re-insert the hose correctly, and this increases the risk of condensation inside the control unit.


Regards,
Wool.

Hi,

I just have a burner assembly from a BW50 here. Looking at it, I don't think it's possible to replace the nozzle individually. The part where the nozzle is located is folded all around the back, and it probably won't be easy to open and close.
I can imagine that you could "grind" the seam all around with a small cutting disc, insert a new tile, and then weld the whole thing point by point... My respect to whoever can do that cleanly. By the way, for the previous model, the BBW46, the tile was still available individually.

Regards,
Bodo.

Thank you for the answers.
I think I'm going to buy the entire burner. I hope everything will work again then.