T.Paasch Posted October 24, 2020 Share Posted October 24, 2020 Hi I have a Webasto Thermo top C in my 2001 Defender TD5. I also have a Telestart installed. When I start up the Webasto, all seems OK. The fan starts, the heater starts, I hear the fuel pump ticking and and warm air is blown into the cabin. But 1-2 minutest later the fule pump stops ticking and the heater turns off. The Webasto fan runs for a while to cool it down and then it's quiet. The fan in the car is still activated, and is now blowing cold air into the cabin. After starting the Webasto, I send a "Status" message to the tele start, the response was: Heater: Started (25 minutes remaining) Aux output: OFF Temperature: 17.0C Battery voltage: 12.99V Sending the same message after the Webasto stopped but the fan in the car was still running, I got this answer: Heater: Started (23 minutes remaining) Aux output: OFF Temperature: 17.0C Battery voltage: 12.93V So my first conclusion is that the battery power seems to be OK. Funny thing though is that if I start the engine, the Webasto keeps running. I tried connecting a battery charger to the battery, but that didn't keep the Webasto running. Does anybody have a any suggestions? Where is the bug? Regards Thomas Quote Link to comment Share on other sites More sharing options...
Sigi_H Posted October 24, 2020 Share Posted October 24, 2020 I had a similar problem with my webasto airtop 2000 When it keeps running, if engine startet, the voltage is to low. The generator puts 13.8 V minimum to the system. Check cables to the heater. When the glowplug in the heater is working at startup, bad connections in the the power line cause low voltage. I had a bad connection in the fuse box. Quote Link to comment Share on other sites More sharing options...
simonr Posted October 24, 2020 Share Posted October 24, 2020 Battery voltage is top of my list! The reports show the voltage after the heater has stopped, and glow plug switched off, so will be higher than when it's on. The most common reason is too small gauge wire used to connect the heater to the battery, followed by duff / corroded terminals or fuses. Si Quote Link to comment Share on other sites More sharing options...
T.Paasch Posted October 24, 2020 Author Share Posted October 24, 2020 Thanks for your comments. If you see the first status from the Telestart, that was while the heater was running. It's connected to an Auxiliary Battery, to make sure the main batter isn't drained. It worked fine last winter, so I guess the wire gauge should be fine. I'll check the wiring that all is good. I have had a Webasto in another car some years ago, and when the battery was low, it didn't want to start at all. I was wondering if it would cut out if the circulation pump didn't work properly (or air was in the system), which I guess would lead to high temperatures in the coolant fluid? Regards Thomas Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 24, 2020 Share Posted October 24, 2020 Is this a water heater? If so perhaps the heater's water pump is failing or the pipes are restricted (or the car's heater is diverting the hot water), so it's heating up a small "blob" of water and cutting out, but when you start the engine you've got the car's water pump forcing colder water around the system and/or the heater valves are actuated and allowing the heater to keep running. Quote Link to comment Share on other sites More sharing options...
T.Paasch Posted October 24, 2020 Author Share Posted October 24, 2020 Yes, as the engine coolant is what makes the "original" heater work on the Defender, the Webasto is attached to the engine coolant system. I guess that's the normal way. This way it also heats the engine - which is a good thing in cold conditions 🙂 Coolant was running low, but I don't know if that some how could have traded air in the Webasto circulation pump. After the few minutes it runs, water in the coolant reservoir is steaming hot. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 24, 2020 Share Posted October 24, 2020 Maybe it's just not circulating through the engine block but bypassing and only warming the heater circuit - either due to the system layout, low coolant, or airlocks etc., so it warms the water in the heater circuit up and then shuts down. Quote Link to comment Share on other sites More sharing options...
simonr Posted October 24, 2020 Share Posted October 24, 2020 Is the water pump riunning? Can you hear it / feel the vibration from it? You could unplug it (furthest plug from the 6 pin plug) and inject 12v to see without the rest of it activated. I'd ruled this out as your reports both said "Temperature: 17.0C", unless that's the ambient rather than water temperature? If there's no circulation, it will overheat & shut down during startup. Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted October 25, 2020 Share Posted October 25, 2020 Hi, The attached might offer you some help. I downloaded it some time ago, but can't remember where from. Mike Servicing a Webasto Thermo Top C Diesel Boiler.doc Quote Link to comment Share on other sites More sharing options...
Tobias Posted October 26, 2020 Share Posted October 26, 2020 i would guess the water pump and/or water circulation and/or low water level, as other people said. Most problems I've had with webastos and volvo heaters have been with water pumps siezing up over summer. Gives your symptoms T Quote Link to comment Share on other sites More sharing options...
Ex Member Posted October 26, 2020 Share Posted October 26, 2020 Your best way forward is to connect a computer and watch all variables during start as it appears to not be throwing a code. Quote Link to comment Share on other sites More sharing options...
Implandy Posted October 26, 2020 Share Posted October 26, 2020 Sounds like its not establishing a flame , especially as everything else you describe is within the start sequence, 2 attempts then it moves to control off. If engine is running and alls ok you need to see the voltage when glow plug is in use. Poor connections are a common cause Quote Link to comment Share on other sites More sharing options...
T.Paasch Posted November 19, 2020 Author Share Posted November 19, 2020 Thanks for all the suggestions. I think the low coolant level was the problem, leading to airlocks in the system. I ran the Webasto while driving to and from work for a couple of days, to make sure there is water circulation and movement, that hopefully would make the air bobbles in the system go away. It seems to work. Now all is working as expected again. 👍 1 Quote Link to comment Share on other sites More sharing options...
Jezzer Posted December 30, 2020 Share Posted December 30, 2020 On 10/24/2020 at 11:13 AM, T.Paasch said: Hi I have a Webasto Thermo top C in my 2001 Defender TD5. I also have a Telestart installed. When I start up the Webasto, all seems OK. The fan starts, the heater starts, I hear the fuel pump ticking and and warm air is blown into the cabin. But 1-2 minutest later the fule pump stops ticking and the heater turns off. The Webasto fan runs for a while to cool it down and then it's quiet. The fan in the car is still activated, and is now blowing cold air into the cabin. After starting the Webasto, I send a "Status" message to the tele start, the response was: Heater: Started (25 minutes remaining) Aux output: OFF Temperature: 17.0C Battery voltage: 12.99V Sending the same message after the Webasto stopped but the fan in the car was still running, I got this answer: Heater: Started (23 minutes remaining) Aux output: OFF Temperature: 17.0C Battery voltage: 12.93V So my first conclusion is that the battery power seems to be OK. Funny thing though is that if I start the engine, the Webasto keeps running. I tried connecting a battery charger to the battery, but that didn't keep the Webasto running. Does anybody have a any suggestions? Where is the bug? Regards Thomas I’ve a few now I’ve just replaced glow pin works fine now this one will run my above ground pool again this year the other is in my shed running two radiators these things are very powerful Quote Link to comment Share on other sites More sharing options...
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