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Webasto termotop C is starting and running for 10 mins and then restarts


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Hey experts 

I have a Webasto termotop C 4 kw installed in my boat. the heater is from november laster year so a very new one. 1 month ago i startede to see the heater run for 40 mins then close down and restart and run again. 

Now it has become so bad that it only runs for 10 min then shut off and restarts. but once it does restarts it only runs for 2 - 4 mins then restart again. if i plug out the yellow fuse i can get it to retry for the 10 mins duration. I can see white smoke out of the exaust when it is starting. so some diesel is burning. 

I got the burn chamber replaced 3 weeks ago and it helped for a 2 days or so. but now we are back. 

Besides that i have replacede the fule line from my pump to the heater. and i have even tryed having 1 meter fuleline before the pump go directly into a can so i am sure nothing is stuck in the tank. 

i have 3 meters from my tank to my pump and then i have another 3 meter from the pump to the heater. Can the pump be tired or something ? 

 

Any tips is welcome :)

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Is your heater a genuine Aftermarket or RV kit  version.....or is it an automotive or HGV version.? 

You probably need to get it analysed, for the fault codes, as keeping on forcing it to work when something is wrong will cost more and more as you fail to fix the actual fault.

 

Edited by matty40s
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16 minutes ago, matty40s said:

Is your heater a genuine Aftermarket or RV kit  version.....or is it an automotive or HGV version.? 

You probably need to get it analysed, for the fault codes, as keeping on forcing it to work when something is wrong will cost more and more as you fail to fix the actual fault.

 

Certainly if it is of automotive origin the higher minimum voltage setting might cause this.

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It is one that was meant to be in a Mercedes cause all the small connection fittings have there logo on :)


what is "higher voltage setting" and what should i do ?  

I hade it checked for faulty codes 2 weeks ago by professionals that pluged a computer to it and no errors was showing up and the heater was running fine for 45 -1 hour then doing a small reboot. and then run again ( i actualy thougt that was normal behavior ) 

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7 minutes ago, TLarsen said:

It is one that was meant to be in a Mercedes cause all the small connection fittings have there logo on :)


what is "higher voltage setting" and what should i do ?  

I hade it checked for faulty codes 2 weeks ago by professionals that pluged a computer to it and no errors was showing up and the heater was running fine for 45 -1 hour then doing a small reboot. and then run again ( i actualy thougt that was normal behavior ) 

 

 

The electronics for the automotive ones are set at a higher voltage (because a car battery is always fully charged withn a couple of miutes of engine starting) A boat leisure bank will normally be much lower than fully charged.

The marine version of the heater has different electronics to function at lower voltages.

 

 

The number of times this has been discussed and yet people still buy cheap refurbished car heaters off ebay.

 

The other problem with the automotive heater is that the exhaust is not safe for use on a boat (it pumps high levels of Carbon Monoxide in to the boat) but hopefully you have at least got the correct marine exhaust system.

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I have a correct marine exhaust system on and i have a ppm alarm on the other side of the hole that takes my fuel and that have never showed any exhaust in the boat.  

I am on a land powered line so my current voltage is 14 (or 14.4 i think) cause the charger is always on. 

Wouldn't the voltage be a problem from day 1 ? and not something that builds up 

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2 minutes ago, TLarsen said:

I have a correct marine exhaust system on and i have a ppm alarm on the other side of the hole that takes my fuel and that have never showed any exhaust in the boat.  

I am on a land powered line so my current voltage is 14 (or 14.4 i think) cause the charger is always on. 

Wouldn't the voltage be a problem from day 1 ? and not something that builds up 

Yes it would ---- providing that your batteries were fully charged at day one and now they are not.

 

An automotive one should  not be fitted in a boat, I am surprised that the guy with the laptop did not reprogram it when he checked the codes. It is only programming. 

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Sounds like a faulty thermostat,or it may be set to a low temperature,cutting out when that temperature has been reached,and then re-starting.

It may be low battery voltage,but sounds unlikely as it is starting up again,and they need most of the electricity on the start up and shut down cycle.

If it has a timer,that may be set wrongly.

It could also be a faulty fuel pump. They sometimes work intermittently before packing up completely.

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6 minutes ago, Tracy D'arth said:

Yes it would ---- providing that your batteries were fully charged at day one and now they are not.

 

An automotive one should  not be fitted in a boat, I am surprised that the guy with the laptop did not reprogram it when he checked the codes. It is only programming. 


My batteries are on 14.4 right now cause the charger is running.  

Could u elaborate a bit on the "its just programming" that really sounds interesting i just have no clue on what to tell the guy with the lap top. 

 

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7 minutes ago, Mad Harold said:

Sounds like a faulty thermostat,or it may be set to a low temperature,cutting out when that temperature has been reached,and then re-starting.

It may be low battery voltage,but sounds unlikely as it is starting up again,and they need most of the electricity on the start up and shut down cycle.

If it has a timer,that may be set wrongly.

It could also be a faulty fuel pump. They sometimes work intermittently before packing up completely.



I have removede my thomostate and are only running with on and off ATM just to besure that was not broken.  (are u talking about thermostates inside the heater that i cant easy replace those i havnt bypassed. )

can i use any diesel pump really want one of the "red once" ppl on this forum says they are better. but allso very expensive :) could i get a very very cheap one and see if that helps and then order the nice webasto pump after once i "traced" the problem to that ? 

 

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16 minutes ago, Mad Harold said:

Sounds like a faulty thermostat,or it may be set to a low temperature,cutting out when that temperature has been reached,and then re-starting.

It may be low battery voltage,but sounds unlikely as it is starting up again,and they need most of the electricity on the start up and shut down cycle.

If it has a timer,that may be set wrongly.

It could also be a faulty fuel pump. They sometimes work intermittently before packing up completely.

that pump is under heavy suspicion :)

I cant say this with 100% certainty but i feel that the click is more mechanical and harder than it was at start. 

And as extra info the heater is running the pump at 2 Hz for the first 5 mins then it slows to 1 Hz for a other 5 min then it closes and restart.   

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The battery maximum shut down voltage is programmed into the unit at build but is re-programmable with the special cable and a laptop with the Webasto software.

8 minutes ago, TLarsen said:

that pump is under heavy suspicion :)

I cant say this with 100% certainty but i feel that the click is more mechanical and harder than it was at start. 

And as extra info the heater is running the pump at 2 Hz for the first 5 mins then it slows to 1 Hz for a other 5 min then it closes and restart.   

That could also be symptomatic of a blocked filter.

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I think the pump has to be the correct one for your make and model of heater.They are controlled by the heater electronics to pump the correct amount of fuel 

Don't understand the Hz you mention.My heater (not a Webasto ) runs at 15 (I am assuming Hz) on minimum heat and 35 on maximum.

As a rough guide,  the pump "thuds"at an army slow march speed on minimum heat and quick chicken running speed on maximum.

Just seen Tracy's post and yes,it could also be a blocked filter.

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9 minutes ago, Mad Harold said:

I think the pump has to be the correct one for your make and model of heater.They are controlled by the heater electronics to pump the correct amount of fuel 

Don't understand the Hz you mention.My heater (not a Webasto ) runs at 15 (I am assuming Hz) on minimum heat and 35 on maximum.

As a rough guide,  the pump "thuds"at an army slow march speed on minimum heat and quick chicken running speed on maximum.

Just seen Tracy's post and yes,it could also be a blocked filter.

Hz,,, cycles per second.   I assume you are referring to 15 clicks per minute?  The OP to 2 a second?

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51 minutes ago, TLarsen said:



I have removede my thomostate and are only running with on and off ATM just to besure that was not broken.  (are u talking about thermostates inside the heater that i cant easy replace those i havnt bypassed. )

can i use any diesel pump really want one of the "red once" ppl on this forum says they are better. but allso very expensive :) could i get a very very cheap one and see if that helps and then order the nice webasto pump after once i "traced" the problem to that ? 

 

 

The boiler will have an overheat cut out, I think that is what was being referred to. Do all the radiators get hot? I suspect not is such a  short time. Do you have any points in the whole water pipework where air locks can form and thus stop or reduce water flow so the boiler overheats.

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1 minute ago, Tony Brooks said:

 

The boiler will have an overheat cut out, I think that is what was being referred to. Do all the radiators get hot? I suspect not is such a  short time. Do you have any points in the whole water pipework where air locks can form and thus stop or reduce water flow so the boiler overheats.

The last one on the pipe does not get that hot. the first once get very hot in the 10 mins 

i have air vents near all radiators.. TBH i havnt ventede them in a while. 

that could allso explain that sometimes it runs more than 10 min (if the air bubble is far a way 

ill vent em all and try again 

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Just now, TLarsen said:

The last one on the pipe does not get that hot. the first once get very hot in the 10 mins 

i have air vents near all radiators.. TBH i havnt ventede them in a while. 

that could allso explain that sometimes it runs more than 10 min (if the air bubble is far a way 

ill vent em all and try again 

 

Its not the radiators but loops in the pipework that I was thinking of. Often with engine room mounted heaters end up with pipes running down towards the floor leaving the heater as a high point where air can collect. It could even be a dirty window on the flame detection part.

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1 minute ago, Tony Brooks said:

 

Its not the radiators but loops in the pipework that I was thinking of. Often with engine room mounted heaters end up with pipes running down towards the floor leaving the heater as a high point where air can collect. It could even be a dirty window on the flame detection part.



U are spot on my heater is mounted in the cockpit bench so it is a bit higher and there is some elevation from and to the heater. have vents on there to. 

i thought it was the flameguard (photocell for the flame detection) replaced with a new one 3 weeks ago (can it become dirty that fast

 

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1 hour ago, TLarsen said:

I am on a land powered line so my current voltage is 14 (or 14.4 i think) cause the charger is always on. 

 

In which case is is probably not the low voltage.

Something to be aware of tho' when you do move off the shoreline.

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1 hour ago, TLarsen said:


I am on a land powered line so my current voltage is 14 (or 14.4 i think) cause the charger is always on. 

Wouldn't the voltage be a problem from day 1 ? and not something that builds up 

If your current and permanent voltage is 14.4, then something is wrong with your batteries, as the charger should slowly drop the voltage to float at around 13.2-6. If one or more of your batteries are knackered, then your Webasto might not be getting the voltage that your battery voltage meter is showing.

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1 hour ago, matty40s said:

If your current and permanent voltage is 14.4, then something is wrong with your batteries, as the charger should slowly drop the voltage to float at around 13.2-6. If one or more of your batteries are knackered, then your Webasto might not be getting the voltage that your battery voltage meter is showing.

 

That makes sense.

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my battery bank and charger are fine. wrote 14.4 just because it tops there now and then when the charger pulses as soon as it takes of it drops to 13.8 and then slowly down to 13.6 then at some point the charger want to pulse again and it bumps back up to 14.4. Sry for the confusion I made in the first post. 

gathering the diesel pipes again now, and tomorrow I will fire it up and vent the entire system. had a tiny tiny hole in one of the radiators, less than a mm in diameter, so i was able to fix it very easy. 

But that hole must have adding air to the system when it was not pumping the water. And I haven't vented out the system after. 

 

fingers crossed. 

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The proff guy that came with his laptop and plugged that in and show a perfect running heater 3 weeks a go. explicitly asked how big my system. because it heated up pretty fast. 

so i am really into the to much air in the system. 

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19 hours ago, Tony Brooks said:

 

Its not the radiators but loops in the pipework that I was thinking of. Often with engine room mounted heaters end up with pipes running down towards the floor leaving the heater as a high point where air can collect. It could even be a dirty window on the flame detection part.


Hey Tony Brooks 

This morning I opened my pipes and used a water hose to clean the entire system from old dirty water to new clean 50/50 water and glucose.  afterwards I ventilated all my pipes / radiators, and now the system runs like a new one.  And the heat on the last radiators on the system are way way hotter now. 

Thanks a lot for the pointers everybody was a huge help when u got a frustrated head ?

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