Wallas Exhaust Problem

seahooked · Posted: Sat Dec 23, 2006 5:46 pm Post subject: Wallas Exhaust Problem

About a month ago the Wallas on my 2006 CD25 filled the cabin with exhaust fumes. I had used the heater a few times prior without problem. On this particular day the Sound was a little rough and (I recollect) I heard a bang, after which I looked under the heater and observed white smoke filling the area. I immediately turned the heater off; and started it a couple of hours later for a few minutes and it appeared to be working. The following week I was out and turned the heater on and again, a noticeable exhaust smell filled the cabin. I contacted my dealer and the local Seattle rep for Wallas. Both recommended checking the exhaust line for obstructions.

Several days later I removed the exhaust hose and verified no critters has set up residence within. However I noticed the exhaust port on the Wallas where the hose attaches had burn marks. Also I had noted the hose clamps were snug but not tight. I reattached the hose, this time with double hose clamps (and tight). Now everything works just fine.

My opinion to what may have cause the original failure was: a large wave on the starboard side of the boat blocked the exhaust port enough to temporarily increase the exhaust pressure to the point where it blew out the weak seal. Once the seal was lost fumes were naturally going to bleed into the cabin. Repairing the seal fixed the problem.

I have had very few problems with my boat since getting it in August. However almost all of them have been leaks related to hose clamps that were 'snug' but not 'tight'. I have since double clamped most of the hoses on the boat (I believe the hot water system is the only remaining- and yes I do have the infamous 'white sealant' as well). Anyway, I love my boat and am very happy with the overall quality but it is interesting how the seemingly minor actions ('snug' but not 'tight') of one assembler on one particular day has the potential to cause lots of headaches if the manufacturer does not have processes in place to ensure consistent quality.

Kudos to Wallas for their tech support. The Seattle rep didn't solve my problem directly but was very helpful. He even gave me his cell number and made himself available 24/7.

flagold · Posted: Sun Dec 24, 2006 9:45 am Post subject:

The "bang" you heard was an afterfire which shot a 2" flame out side of the boat like a shotgun blast. I happened to be looking at my exhaust when it did it one day (and then saw it many more times as I tried to get it fixed). The white smoke is the residual from the afterfire. Great you had such a simple fix.

journey on · Posted: Sun Dec 24, 2006 10:04 am Post subject:

Flagold, how did you fix it?

Boris

macmac · Posted: Mon Feb 12, 2007 8:02 pm Post subject:

What are you using for fuel?

seahooked · Posted: Mon Feb 12, 2007 9:52 pm Post subject:

macmac,
Not sure if you are asking me or Flagold. I use Klean Heat which is a product similar to kerosene; but suposedly burns cleaner.

Jeff Brigner · Posted: Mon Feb 12, 2007 10:08 pm Post subject: Wallas

I was told by the Wallas rep at the SBS to use fresh deisel from the pump. He claimed that fresh fuel and the new low sulfur fuel was the best. When I told him I used K-1 he told me to stop immediately.
Seahooked, welcome to the plumbing not so snug clamped white goop group.

seahooked · Posted: Mon Feb 12, 2007 10:15 pm Post subject:

Jeff,
Do you know what the problem is with K-1? When I talked to a Seattle Wallas tech a couple months ago he led me to think it didn't matter whether K-1, Klean Heat, or diesel was used.

Dora~Jean · Posted: Mon Feb 12, 2007 10:17 pm Post subject:

I got the same response from Scan Marine, but then again he said he was unfamiliar with Klean Heat. He said K-1 will tend to goop up while sitting and needs to be dumped or filtered before using it after a layup. Klean Heat I understand is mostly (maybe completely) synthetic and doesn't tend to goop up. Wish I knew for sure, no problems in 1 1/2 yrs with Klean Heat. Might have to do with the climate and climatic changes.

Jeff Brigner · Posted: Mon Feb 12, 2007 10:23 pm Post subject:

flagold · Posted: Mon Feb 12, 2007 10:43 pm Post subject:

Sorry Boris, didn't see your question.

After disassembling the unit many times, and trying a new igniter and other parts, ended up sending to Karl at Scan Marine and turns out it had a bad fuel pump. The last few times out it has run fine, so at the moment I'm not complaining. I got the same advice as above (use only fresh diesel). I don't know what the advice is now (it seems to fluctuate), but that is what I was told at that time (and do).

Best Day · Posted: Tue Feb 13, 2007 12:12 pm Post subject:

I was also told at the SBS, by one of the guys at Scan Marine, that the best fuel to use in the Wallas is diesel. I told them that I had read here that Klean Heat was the best to use because it didn't soot up the Wallas. They stated that the Wallas will run on many different types of fuel but was designed to run on diesel. They said the new diesel is of a higher quality than the old type.

I originally started talking to them because when I use my Wallas I get an odor of the fuel. They said switching to diesel may solve this problem. I have checked all connections and they appear tight. Anyone else smell the fuel when they run their heater?

Thanks,
Bill

Sea Wolf · Posted: Tue Feb 13, 2007 1:02 pm Post subject:

Bill-

Since the Wallas vents externally, you're probably smelling raw fuel from a minor leak. Several folks have found that their Wallas did not have the fuel connections tightened sufficiently, even on new boats. Have you checked your connections on the fuel lines?

Can you tell from the smell if the odor is from raw fuel or exhaust? Does the external exhaust smell the same?

I'd wipe everything down on the supply lines and let it air out so any fuel would evaporate, then start it up. Stay out of the cabin to keep your nose "fresh".

Then after 15 minutes thereafter and at 15 minute intervals, go in and wipe down each connection, one at a time, and take the otherwise clean rag out in the cockpit and smell it for fuel residue.

Or, could the smell be coming from the tank? Check out the venting, fill cap, etc.

Of course, it's also quite possible that the stove may be leaking up inside around the fuel pump, etc. Another place to examine, with and w/o pressure in the system.

Hope this helps!

Joe.

SEA3PO · Posted: Tue Feb 13, 2007 1:47 pm Post subject:

I have a propane stove so I don't have any of this....but my question is.... has anyone tried Bio-diesel ??? it is made from vegetable oil... and I wonder if it has the same sooting problem...or if it gels... I know when it burns it does not smell bad like fossil fuel. Anyone tried ??

Joel
SEA3PO

drjohn71a · Posted: Tue Feb 13, 2007 2:35 pm Post subject:

Best Day - I don't see what C-Dory you have, but I have noticed Wallas exhaust coming into the cabin on my TomCat 255 under certain circumstances: 1- high winds blowing into the starbord exhaust hole, 2-going over 24 knots in windy conditions, and 3-frequent, high waves slapping the exhaust hole.

I was wondering if one could get a vertical extension to add to the existing Wallas exhaust to eliminate these problems.

John

Sea Wolf · Posted: Tue Feb 13, 2007 4:14 pm Post subject:

John-

Would a clamshell style vent cover do the job?

Joe.