41DS Webasto Heating Problem

[dave346]

I have a 2015 41DS, the heating has never been any good, even on max and all the vents closed other than the saloon. Boat never seems to get very warm. Did have someone look at it once and was told it’s all fine. Somebody thought I should insulate the vent pipes, but having just spoken to another DS owner, he’s gets hot and hasn’t insulted his pipes, so I must have a problem somewhere. Any thoughts on how to make it hotter and what the problem might be ? Thanks

[zaphod]

Having all the vents closed can cause a problem because the restricted airflow can cause the heat exchanger to get too hot and cut out thermal protection.

Open all the vents and measure supply air temperature. Watch the control panel for any flashing lights that would indicate a fault.

[Charlie-Bravo]

Have a good check of the air inlets, both combustion and heated air, obstructed 'air in ' will result in little heat, and perhaps overheating of the burner.
These heaters and Ebers are simple enough , a diesel flame heating a lump of alloy over which the air flows to heat the boat, but with lots of finicky parameters of available air fuel and voltage, and if the set up dares to go outside of the parameters it will possibly cut out, and then cut in again, or run in tickover mode, or not bother starting up at all.

The air side can get obstructed, or a duct squashed, too many duct bends can also reduce overall performance , spoiling the joy.
If it fires up and keeps running ,  then the fuel side would seem ok.
You don't mention the KW of the model you have, .... 4 to 6 KW should keep you toasty, if you have a 2 KW model it might be worth an upgrade, which would be a simple install as running the ducts is the hard bit, but even 2 kw should be warmish.

When was the burner and alloy heat exchanger last cleaned / serviced?

Insulating ducts can be a waste of time as the ducts are inside the boat, so any heat loss goes ... into the boat.
some might say you loose a bit of heat at the outlets but it's marginal, ducts running through cockpit lockers might benefit a bit.

I added a cockpit outlet, and mid winter the whole boat and cockpit canopy gets too hot and I have to turn it down.
(4kw eber heater )

CB

[dave346]

Thanks for the replies. Only closed all the vents for a test and made no difference, no flashing lights on the controls. From the Webasto unit all pipes seem fine and traced the inlet to the port aft locker and all good. Out vents seem to go behind the cabin units so will take a bit more effort to check. It’s a 5.5kw unit so should be really hot then. Will do some more checking tomorrow. Cheers

[Mistroma]

I suspect my 2009 42DS has the same Webasto heater. It is fitted on starboard side in the stern under the gas bottle locker. None of the ducts are insulated. It heated the boat quickly in winter on West coast of Scotland. Plenty of heat and the whole boat was really warm. I slept on board in the yard a couple of times when it was about -2C outside and it easily kept the boat warm and mostly ran on quite a low level.

Certainly something wrong if your unit isn't putting out much heat. It is too hot to keep your hand in front of the Saloon outlet when it is going full blast.

[Charlie-Bravo]

I guess you might, as a first check, disconnect the duct at the first branch after the heater, or if that's difficult because of access, perhaps just take the duct directly off the heater,  fire up, and see if you are getting a hot breeze out of it, and if it's a bit tepid, ( should be jolly hot at the heater, use gloves or a thermometer to test) then the heater unit may well benefit from a strip down to find the fault.
Interested to hear how it goes. ......... any service history? , a lot of owners just keep running these things until they don't .
CB

[sailor666]

I had a similar problem. I was lucky enough to notice that the back of the aft cabin locker was hot. Turned out that an outlet tubing connector behind a panel at the back of the locker had come disconnected and the majority of the hot air was spilling out ineffectively. Reconnecting it fixed the problem and the boat is now toasty.

[bereboot]

Which webasto do you have, i mean is it big enough?

[dave346]

Thanks for everyone’s feedback, ran a few tests today. What I forgot to mention in my first post is you can hear the fan run faster for the first ten minutes when first switched on, then it goes to snail speed, even though the boat it’s warm , and that’s with the thermostat on max and control on plus. Anyway when it’s first started I removed the air out pipe and it was roaring out supper hot, and you can feel that in the cabins when I put the pipe back. So don’t think I’ve got an outlet pipe issue. But obviously that only last for about ten minutes. Did the same on air in, thought with that pipe disconnect it ran faster longer but it still eventually cut down, so that could have been my wishful thinking that the pipe in was blocked. Must admit the right angle the pipe does in the port stern locker before it goes out looks very tight, and the baffle on the transom does look very restrictive, but guess all 41DS are designed like that. Personally I suspect the temp sensor in the saloon, it’s fitted on the left of the microwave. Is there any way of disabling that, or overriding it so I can make it run at full speed max heat for as long as I like until I turn the fan speed down on the control panel ?

[Charlie-Bravo]

Well it's good news that the burner can produce the heat .... all be it for 10 mins.

Yes the temp sensor /thermostat could have become faulty , you might be able to bypass it , but it probably isn't a great idea , and I have no experience of doing that,  .... also, ( and as you haven't mentioned the service history)  the burner might be getting too hot after 10 mins as it is full of coke ( not the drink ) . most burners have a temp sensor to stop them going into meltdown, and setting the boat alight ! ( doesn't happen often ..... but ).

Maybe a good course of action might be to take the burner out, take it apart for a clean and service, ( or give it to a workshop if you are not the fiddling type) to ensure the bit with the flames is in good condition, and then if it doesn't behave, replace the thermostat with a new one.
Hope it goes well for you.
CB

[dave346]

It has only been serviced once in 6 years, all be it’s never been that great from new, although comparing it to my Espacher on my last Moody. Heater is only lightly used, we’re actually in the Med but the weather has been so rubbish here recently I’ve been trying to warm the boat up at nights. If I’m feeling brave I might take it apart then. Thanks

[ales]

Had similar problem.
Check how the webasto and the hoses are installed. It all should be on one side of the boat. When I bought my boat it had Webasto on starboard and the hoses continued on portside.

Then check also the inlet hose for fresh air.
Webasto should or must get fresh air from outside to work properly.

After what you described it seems to me it is overheating. Does the green light flashes? I think 10x times is overheating.

Do this before going to thermostat.

[sailor666]

The electronic controls are surprisingly (to me at least) complex. I too had Eberspachers on my previous 2 Moodys and the Webasto was a new experience on my current (now quite old) Jeanneau. I’m in the UK and use the boat year round but like my comfort so the heater gets a lot of use. I’ve found the Webasto to be head and shoulders more reliable and easier to live with than the Eberspachers. I started off with annual servicing of the Webasto but the agent eventually persuaded me to stop and only intervene if something goes wrong. I did have a fault develop after about 3 years where the heater would shut down after a time (I forget how long). After several attempts to find and fix, I replaced the entire heater - except for the timer controller unit as I didn’t want mismatched holes in the interior woodwork…
…the fault remained.

Changing the timer controller unit for a new one finally fixed the problem. Maybe if I had started there…

Throughout this, I have nothing but praise for the Webasto agent who went to great lengths to find and fix the problem before suggesting a replacement. They gave me an extremely good price for the replacement and I now have a much quieter heating system than before. (I made a teak sub-panel to cover the mismatched hole in the interior)

It is worth persevering with.. Good luck.

[Charlie-Bravo]

"Changing the timer controller unit for a new one finally fixed the problem. Maybe if I had started there…"

You know no the rule of Sod applies without mercy!

I too came from Moody with Eber , perhaps it is a rite of passage thing, and once qualified , see the light and go Jeanneau ( still miss the old Moody a bit though) I installed a new Eber and am pleased with it, a vast improvement in quietness, control and ease of use compared to the old one I had,  I guess it's progress .
CB

[NZL50505]

You said it’s a 5.5KW unit which as others have confirmed should be more than enough. I had same on a 42DS and it made the boat too hot at times.

If it’s not working properly I would suggest getting a registered Webasto servicing agent to tackle it.

I’m always wary of these things. Whilst they have protections built in they can (and have) caused fires from malfunctions. They are a combination of fuel, heat, electrics and electronic controls in an inaccessible space. Whilst the engineering is not complex in and of itself this combination of multiple systems in inaccessible locations makes it daunting for a non-confident amateur (like me) to tackle.

And so if you are in a similar position I suggest getting help!

[Trevor]

That is the same unit we have on our 42DS. So far no problems ( touch wood).

To check the thermostat you could try hearing it with a hair dryers ( heat output will go down) or chill it with some spray freeze ( that should
Make it go flat out). If no change occurs you know the thermostat is not working.

Regards

Trevor

[dave346]

So have decided to get it serviced, although now isn’t a good time as just got back to the UK for a bit, and when we’re back out to the boat in May I don’t think I’ll be needing it (the boats in Spain), so it’s definitely on my winter maintenance list next year.

What I did do before we left was to move the thermostat to a cooler part of the boat, in another cabin where the vents are closed. And I’m convinced it got a lot hotter in the main saloon, so much so that we had to turn it off as we were getting too hot. So definitely think its a thermostat problem, but as some of you have advised I won’t fiddle with it myself and at some point I will get a professional in.

Thanks for all the advice.