Community Forums

EMaznio · 06-01-2013, 06:42 PM

I have a diesel smell coming from the AquaHot bay and I can't figure out its origin. I don't see any leaking fuel inside the compartment, on the equipment or under the coach. The smell leaks up into the water closet quite strongly. Suggestions?

Edward Maznio
2001 Monaco Dynasty 40 with Tag

Mike Canter · 06-01-2013, 07:04 PM

I have smelled that diesel fuel smell coming from the Aqua Hot bay on every MH I have stuck my nose in including mine. I have washed the compartment with 409 and if is still there. If you get a heavy diesel exhaust smell and maybe a little black smoke when it is running then it is time for a fuel nozzle change. The precision jet hole in the nozzle wears from fuel running through it and then they run rich and smell.

Lee0920 · 06-01-2013, 07:34 PM

Would guess that your unit is starting to run rich so you have unburnt fuel that you are smelling, check out this web site, if it is Aqua Hot related they will have the answer.

RV Hydronic Heater Forum

CoCoDave · 06-02-2013, 08:34 AM

My Windsor was eight years old when purchased 2 years ago. It had seen very little use and what use it did see did not often involve the Aqua Hot. The Diesel smell was almost overpowering. When we started using the Aqua Hot on a regular basis the smell diminished.

A problem discovered and corrected during the initial service was that the air/fuel mixture adjustment was biased toward too little air and too much fuel. Correcting that, along with a nozzle change and combustion chamber cleaning, pretty much eliminated the Diesel odor which supports Mike's and Lee's observations above.

FWIW

drnitrous · 06-06-2013, 09:32 PM

I just went through a similar problem with my 2002 Dynasty Regal Tag. It turned out to be the fuel pump was leaking causing the problem. If yours has the original cast style pump they are very prone to leaks and when most rebuild them they replace them with the new billet pump that is widely available. I disassembled mine twice thinking it was the bango fittings leaking but what it turned out to be was the front fuel pump seal blowing a lot of extra fuel into the combustion chamber making an excessively rich mixture, the smell was overbearing, weird thing is the exhaust was never colored but it did smell rich to me. I never saw fuel anywhere until I removed the Aquahot cover and there was some fuel on the bottom of the case, with the pump leak the fan will blow most of it into the combustion chamber and despite what one may think it doesn't run all over. I agree, a plugged fuel nozzle could give you similar symptoms especially if the nozzle is one of a bad run of nozzles that was out there a few years ago that didn't seal when seated, there was a problem with the way the mating surface was radiused. Roger Burke and I beat our heads against the wall for a while on it, he thought it was the pump from the get go, I was pretty convinced after I had it out a couple of times, and he was right. I replaced the pump and the smell is gone. The convincing point for me was with the cover off when the system fired I could see some fine drops exiting around the flange on the combustion chamber. Just a thought, hope it helps.
Brent

Coma · 06-07-2013, 06:48 AM

Mine has a bit of diesel smell, too, FWIW.

On a side note, I think diesel has a fine smell. The finest being JP-5 mixed with an overtone of MilSpec turbine oil on a slightly warm (from previous day) J79. Diesel being its close cousin. DW even likes it's charming aroma. I will admit that not all are entranced by its exotic nose.

Mike Canter · 06-07-2013, 06:52 AM

Yes Jim got to agree with on the scent of JP it is almost as good as burning methanol. Brings tears to the eyes.

Les Stallings · 06-07-2013, 10:34 AM

Quote:

Originally Posted by Mike Canter

it is almost as good as burning methanol. Brings tears to the eyes.

Literally! You crack me up...

Mike Canter · 06-07-2013, 11:59 AM

Not talking about meth. Talking about methanol alcohol racing fuel. Just want to make sure everybody understands that.

EMaznio · 06-13-2013, 07:23 PM

Thanks everyone! I've left the AquaHot running for a couple days and it now runs with very little exhaust smoke and the smell is pretty much gone (to my satisfaction). Initially, it spewed out lots of black smoke and soot onto the ground in chunks. I think I have that behind me now. Thanks again!