Community Forums

scorpodoc · 10-17-2018, 06:58 PM

Hi all,

I noticed some white smoke at rear of coach after I turned on diesel burner...
when I went to turn diesel burner on again the next day the green light goes out after a minute or so.. any ideas what is happening and what I need to fix it.. getting colder tonight.

Thanks to all

36 ft Alpine fdds

ByeTheWay · 10-17-2018, 08:16 PM

Professional advice is available for FREE for the DIYer online at: Roger Berke: RV Hydronic Heater Repair: RV Hydronic Heater Repair - Home

Gary Arnold · 10-18-2018, 08:48 AM

When the diesel burner light goes off after turning on. There is a fault and it is locked off. This happens when it attempts to ignite the diesel burner and it fails. There are many things that can cause a failure to ignite.

To reset and try again turn the switch off and back on. If it keeps failing I would start with the basic maintenance…cleaning, filter, nozzle and adjust spark igniter.

Renipladlo · 10-25-2018, 10:59 PM

All - Its been a while since I serviced mine, however, we rarely use the DB part. The Government mandated ULSD Fuel in 2012 I think, and sulfur was reduced to 15PPM or less. That cleaned up a significant problem with the HH DB's needing to be serviced every other year or so. If you turned off the switch prior to the burner going inactive and running the cool down cycle (Fan noise, with air flow cooling down out of exhaust pipe), then fuel is/was still present in combustion chamber and will cause lots of black or white smoke next time you start unit. If you have not used it in a while, it will most likely need to be turned off and on a couple of times since fuel has evaporated or drained out of the line a tad bit. This happened to me the other day, and a little smoke as well. Still it's been 4 years and it's time to service it. Suggest you download the manual from Aqua hot, and read up on how to service it, before you do it, as there are some tricks you need to know prior to doing a service. If your external fuel filter for the HH does not have shut off valves, you will have to pinch those hoses closed so you do not spill fuel all over the ground, etc. NAPA makes or sells some handy plyer type clamps with smooth flat jaws which will not damage those hoses, crimping them off. I keep two sets of each size in my tool bag, as you will need the large pair of them for the fuel filter change on the genset as well.

bobkathy95 · 12-21-2018, 12:24 PM

I too, am having the same problem. Bought the coach in October and I know AquaHot was working. Today, I turned on the diesel burner switch and after about 25 seconds it (the green light) shuts off. The burner never comes on. A check of the control panel in utility panel shows Green light on Element Status and Heating status. The Electric switch seems to work just fine. When the Diesel switch is turned on, Pump #3 light is also on green. I checked the 20amp fuse located just below the Electronic Control panel in utility bay - it checked out ok. I also have receipts where the previous owner replaced the nozzel and had the burner reconditioned last April. I also checked the breaker on the main circuit panel inside the coach. Probably am missing some really simple procedure - but I sure can not figure what it may be.

DrDaveMA · 12-22-2018, 02:03 PM

Quote:

Originally Posted by bobkatgifts

I too, am having the same problem. Bought the coach in October and I know AquaHot was working. Today, I turned on the diesel burner switch and after about 25 seconds it (the green light) shuts off. The burner never comes on. A check of the control panel in utility panel shows Green light on Element Status and Heating status. The Electric switch seems to work just fine. When the Diesel switch is turned on, Pump #3 light is also on green. I checked the 20amp fuse located just below the Electronic Control panel in utility bay - it checked out ok. I also have receipts where the previous owner replaced the nozzel and had the burner reconditioned last April. I also checked the breaker on the main circuit panel inside the coach. Probably am missing some really simple procedure - but I sure can not figure what it may be.

Bob, I am sure there will be an AquaHot vendor at the Tampa Super Show that will service it for you.

dennismhamm · 01-01-2019, 09:43 AM

Mine did the same thing and it was the silver control box thats mounted on the side of the burner. Replaced it and all is well

bobkathy95 · 01-01-2019, 01:57 PM

Quote:

Originally Posted by dennismhamm

Mine did the same thing and it was the silver control box thats mounted on the side of the burner. Replaced it and all is well

Thanks. I unplugged, checked and then re-plugged every single fuse, wire connector and controller card plugs. I also downloaded the AquaHot service manual and performed all the checks. At this time - my system now seems to be working correctly. Best guess - some connection somewhere was not getting a strong enough signal and I "accidentally" fixed it. Time will tell.

To DennismHamm: thanks, that is what I will look at first if it malfunctions again.

DrDaveMA · 01-02-2019, 07:40 PM

Quote:

Originally Posted by dennismhamm

Mine did the same thing and it was the silver control box thats mounted on the side of the burner. Replaced it and all is well

All of the controls (temp, level, etc,) report there. Could be a loose connector.

Spk64 · 01-02-2019, 07:50 PM

Quote:

Originally Posted by dennismhamm

Mine did the same thing and it was the silver control box thats mounted on the side of the burner. Replaced it and all is well

I had similar symptoms and had to also replace the Webasto burner control box (Silver box).

The diesel light switch going out indicates a fault in the Webasto control system. Could be any part of Webasto burner system. Troubleshooting the coil, flame sensor would be easy things to check first as the control box is pricey.

I spent considerable time checking all the components in the Webasto system. Even built a test panel to manually operate it.
When system is first turned on and starting to fire I could tap on the silver box and it would take off. This finally convinced me to spend the money and replace it. Has worked great ever since.

Something to keep in mind is that after it is working correctly it may smoke some till all the excess unburned fuel is gone.

Edit:
Couple threads on past experiences.
http://www.irv2.com/forums/f103/hydr...ng-348490.html
http://www.irv2.com/forums/f103/2002...ce-243811.html

EngineerMike · 01-05-2019, 10:38 AM

OP- there is a gizmo next to the burner nozzle called a flame sensor, mine is connected w/2 bullet connectors. Could be the flame sensor is bad, could be the connectors(or 1 of them) isn't connecting well (that's what my problem was when it was 16 degrees outside), or it could be dirty & just need cleaning. Also could be controls. You have to remove the burner head to check the sensor but don't have to disconnect the plumbing to it.