Aqua Hot blowing black smoke after changing parts

[Jeff Bayley]

I just got mechanic buddy of mine to change out the prescirbed parts as suggested on Prevostman.com I belive there were two parts totoal I replaced. It has just stopped working / firing becuase I probabley failed to start it once a month and excersise it. I threw him the insturctions and the parts. After, the burner fired but it was throwing off way too much soot and black exhaust. If there a fule mixture of something of sorts that would be making it it blow to rich or is there some other oversight.

Thanks in advance for any suggestions.

[Ray Davis]

If you go to the vehicle systems website, there is a service manual available, complete with trouble shooting section. I don't have a link instantly available, but you can easily find it.

Off hand, I would check that you gapped the electrodes correctly.

Ray

[Yankee802]

When it got cold enough this fall and I ran the wabasto for the first time since purchase (May) it was at night, but was throwing a TON of "sparks". Being it was at nite, I couldn't tell if there was smoke or not, but I'm guessing there probably was. Either way, after a little time it stopped 'sparking' and is fine.

I'm mentioning this because if yours hasn't been run in awhile and due in part to it being non functioning, it may just have to clear its throat, as it were. Of course this is just a guess, I'm not a mechanic. :)

Geoff

[sawdust_128]

Jeff:

I am no expert on this system, but I will try to help as best I can.

If I were in your position, there are several things that I would check. Also, I agree with what Jeff stated, If it hasn't been run in a while, it mak need to cook a bit.

1. The combustion chamber is clean?

2. I assume your mechanic put in a new nozzle. Aqua hot is very specific that your first tighten the nozzle, back it out a 1/4 turn and tighten it down again. They stress that in order for it to function properly, there can be no leaks around the nozzle fitting. Their procedure minimizes the risk of leaks.

3. All over the manuals, it always states that new nozzles can be defective. You are supposed to check the spray pattern after replacement. You are supposed to see a spray of fuel as a fine mist in a conical shape.

4. There is a combustion air intake. Is it clear? There is an adjustable shutter on it. Has it gotten inadvertently closed?

5. Was air introduced into the fuel system when the filter was changed?

6. Is the exhaust system clear? Did critters build homes in it?

I am not sure I agree that this is a problem with the electrodes. You are getting this to fire and it continues to burn. Once the fuel is ignited, the flame detector photocell will shut off the flow of electricity to the ignitors. In the dark, this photocell develops only a nominal resistance. Thus, current flows through it to the ignitor. Once exposed to light from the flame, resistance jumps to 300k ohms and it essentially cuts current to the electrodes. Combustion is sustained by adding fuel and air in the appropriate combination to the existing flame.

At least on what I am looking at, there is a fuel pressure regulator which is adjustable, on the fuel pump. You are supposed to install a fuel pressure gauge in place of the nozzle and you should detect 145 lbs (?) of pressure.


I hope this helps until the experts show up.

Good Luck.

Manuals: http://www.aqua-hot.com/b2c/ecom/ecomEnduser/default/ArchievedManuals.aspx

[Joe Cannarozzi]

Try running it through a few cycles to get the cob webs out of it it may clear up. Put a new fuel filter in it too.

Did you catch that Erik?

[MangoMike]

Hi Jeff,

I would also follow Joe's advice and let it run for a number of cycles.

Sawdust is correct on the electrodes. Once the unit fires they are done for the cycle.

Defintetly a fuel to air mixture issue.

As I recall Tuga had an issue with his smoking and it turned out to be the voltage to the Webasto head. Low voltage and the fuel pump will run and burn but it won't move the fuel at the correct rate. I would make sure you're getting 11+ volts.

Here is a very good service manual on the Webasto, (which is what Aqua Hot uses for the heating head).

http://www.suremarine.com/manuals/webasto-repair-manuals/dbw2010-2020-300-repair.pdf

See page 18 for trouble shooting on the smoking issue

Mike

[Jeff Bayley]

Thank you for all the suggestions. Will dig into it tommorow or the next day.

Thanks to all.

[merle&louise]

Jeff,

MM is right; mine was smoking after I changed the fuel nozzle (black smoke if I remember correctly). It was being caused by low voltage; my alternator died @ POG II in Santa Fe. Once I got home and had the alternator re-built the smoke went away. Low voltage will definitely cause Aqua Hots to smoke. :eek:

Something else to check would be to make sure you have the correct fuel nozzle. Mine uses a 35mm nozzle; double check your manual or call Vehicle Systems, 800 685-4298 in Colorado (Dan Clark x 311).

[Jeff Bayley]

I sent Mango Mike this email to see what he says but welcome other comments:


Hi Mike- Jeff here from POG. I put a posting on POG about my Aqua Hot billowing gads of black smoke after I had my mechanic friend change the parts you suggested in your web site write up. The Part number 341304. There was another part in the box and I think that was the gauge. I know it isn't hard to do but he was around and bored so I gave him your printed out directions and the parts to change.

On POG, I got the following reply. I can't readily identify the model number on my Aqua Hot to download the correct manual from the following site.

http://www.aqua-hot.com/b2c/ecom/eco...edManuals.aspx

The post someone put below gave me pause about the right part numbers so since your the pro I thought to see what you thought. I just cycled it again and the black smoke turned to grey but it seemed to have less volume of smoke coming out as well. I was inside so didn't see it turn. Just a lot of black when I went in the house and a medium amount of grey 10 minutes later. I've shut it down and will wait for it to cool and cycle it agian. Is this what you would endorse ? Thanks. POG reply to my post follows: Oh, I don't have low voltage. The bus is plugged in.

[sawdust_128]

Why can't you identify it?

[Jeff Bayley]

Sawdust-

There's no model number on the outside stainless part of the unit. No sticker, no stamp, no nothing. I clicked on one of the dozen manuals and it said "RV System" or something to that effect. I talked to Mango and he told me to cycle it a few more times but after 4 cycles it's still blowing smoke black as all get up. It turns to grey smoke and throttles back. I think this is a cool down cycle but it never actually stopped blowing the grey smoke. I let it cool down (presumabley) for 10 minutes or more and still grey smoke. I shut it off all the way at the dash.

Sawdust- What's your latest estimate on coming to Florida ?

[sawdust_128]

I went through the same process of identification. I ended up pulling the shroud and found the ID plate in there, bottom, front corner of the shrounded (now exposed) area, on the bottom-front of the vertical wall on the right side. If you look at the AHE-100-02S (http://www.aqua-hot.com/b2c/ecom/ecomEnduser/staticpages/documents/AHE-100-02SAqua-HotOwnersManual05-02.pdf) owner's manual in that archive at AH's web, there is a diagram that shows 2 locations for the Product ID plate(s).

Also, although Aqua Hot Heating System Inc. has a section for archived manuals, but the archive is incomplete.

If there is no plate inside the unit, call Aqua Hot Tech Support 1-800-685-4298 or email them
http://www.aqua-hot.com/b2c/ecom/ecomEnduser/default/TechSupport.aspx and they will walk you through the ID.

If you get that done, then everyone will know that something is broke and not just incorrect parts working as they should, but poorly in your system. As the saying goes, the Devil is in the details.

I wil PM on the other question.

[MangoMike]

Jeff,

Let's get back to basics with your problem. Which I believe boils down to a improper fuel to air mixture.

According to the experts at Webasto if the unit continues to smoke after a number of cycles then you need to:

Make sure the combustion chamber is clean. You'll need to remove the head to do this. See http://www.prevoman.com/Pages/Webasto/Webapage1.html

Then you need to pull out the chamber. It is usually in their pretty tight, but it will come out.

3868

This needs to be cleaned on probably an annual basis.

Make sure the head is seated properly during reinstallation. OTherwise excess air will enter the chamber. One note of caution the two tabs that bolt the the head to the chamber are cast iron and will snap off if you crank them down too hard.

The other issue is the air intake, which I'm told by Webasto tech support not to mess with unless you're at high altitudes. Make sure there is nothing blocking the air intake.

Improper voltage can can affect the main motor. I would verify the voltage into the system.

3869

Or if this motor is not up to par, less air will be reaching the combustion chamber. Since yours is apparently running, I'm not sure what the test would be to make sure it's at 100%. Perhaps some Pogger can help out here.

The fuel system to the pump/nozzle unit is circulatory. So that unused fuel is returned to the fuel tank. According to Webasto if this return line is slightly blocked it will cause higher fuel pressure to the nozzle. Thereby increasing the amount of fuel to the chamber and causing smoke. Frankly I've never heard of anyone having this issue.

IF the above doesn't work, then short of finding a qualified repair facility in your area, I would start replacing additional parts like the motor (which controls the air fan) and possibly the fuel pump. That's my non technical approach, just start replacing parts.

[Ray Davis]

I have one dumb question. Mike is describing things for a Webasto, and Jeff has an AquaHot. I know they are similar, but are the similar enough that the main burner unit can be treated as the same as a webasto?

Ray

[MangoMike]

Ray, there are no dumb questions, only dumb answers.

It's my understanding that Aqua hot uses the Webasto burner for their unit. They would use either model 2010 or 2020. The 2020 produces more btu's.

I'm sure I'll be corrected if wrong.

Mike

[sawdust_128]

Ray, there are no dumb questions, only dumb answers.

It's my understanding that Aqua hot uses the Webasto burner for their unit. They would use either model 2010 or 2020. The 2020 produces more btu's.

I'm sure I'll be corrected if wrong.

Mike


Jeff: To add here, there is a burner ID Plate on the top backside of the burner head. That plate should contain the Webasto model number that Mike describes above. With that in hand, you will then be able to determine if the parts you installed are correct.