Aqua Hot Diesel Not Lighting

[jana0623]

I have an Aqua Hot 400-D in a 2015 Tiffin Phaeton 40-AH (all electric) coach. Yesterday the temperatures were warmer, so I'd turned the diesel boiler off, leaving the electric on.

This morning when I turned it back on to get heat, the diesel didn't start or ignite. When I look at the indicator lights on the control panel, everything that's lit is green, including: Electric Heating Element Status, Heating Zone Status #1, Low Temp Cutoff Status, Pump #1, Diesel-Burner Status. Inside, the heat exchanger fans are blowing cool air.

When I turn off the diesel boiler for 30 seconds and turn it back on, a pump comes on briefly, then goes back off. At least that's what it sounds like.

Up until now (since January, we're full-timers), it has been our main source of heat, not to mention hot water.

[obedb]

I know nothing about your system. Posting is low today because of the Holiday I guess. Can you hang in there? I will send a PM to a friend on this site. There is a site very favorable to Tiffin owners on the web. Look for it. Good Luck. Hope you have an electric heater for the bedroom.

[jleamont]

Jana0623, create a user id a password on this forum and post the problem on it.

http://forum.rvhydronicheaterrepair.com/activity.php

Rodger operates the forum, he has been a tremendous help to me figuring mine out and sourcing parts.

You can also call Aqua Hot tech support at 800-685-4298 7am-4pm mountain time.

I have a hunch you have low fuel pressure, maybe a clogged filter, dirty or failed photo plate in the burner (if the photo sensor cannot see a flame from the burner it will shut it down just after start up)

It's not a difficult fix depending on where the unit is mounted on the coach for access and your skill level with tools.

If you decided to take it somewhere for service, check the Aquahot website for the list of authorized repair centers. I would not recommend taking it somewhere that is not on the list, most will only guess at it and I have heard they often install the wrong parts due to lack of training. Their guessing will only coast you longer down time and an expensive repair if they can even get it right.

Good luck

[five]

Also, the diesel burner will not work if the fuel in the main tank is lower than a certain point.

[kaypsmith]

Five, that is my same thought, pickup tube is mounted higher in the tank to prevent using up fuel that will be needed to crank and move the coach to refuel, just like the generator.

[casuall454]

2015 unit. Warranty maybe?

Otherwise the units are fairly simple in operation, however trouble shooting your problem has several possible causes:

1) Fuel filter restriction

2) Fuel pump low flow

3) Injector nozzle is 0.35 @ 60 degree spray plugged / restricted flow. (please don't try to clean a nozzle, just replace it)

4) Photo cell cracked (lens is glass), can be soot build up on lens. Unit doesn't receive flame code and shuts down.

5) Initiator out of adjustment, not igniting diesel.

6) Air filter dirty, low CFM flow again causing unit to burn rich = dirty.

Aqua hot in 2013 changed the burn chamber from 18gu sheet metal to 0.125 steel. Any person who is servicing their older unit can upgrade to the new steel burn chamber, be sure when you reinstall to place hole to bottom as that is exhaust port.

Additional information http://www.aquahot.com/esource/ecom/esource/staticpages/documents/450-DE2%20Service%20Manual%20Rev%20C.pdf

[hermanmullins]

Jana,

When was the last time your unit was serviced? Sounds like all of the above suggestions could be your problem. Both things on your coach that uses diesel, Aqua Hot and Generator, will not work if your fuel is at or below 1/4 full.

Aqua Hot units are very good when working but they must be serviced once a year and run at least once a month. I will pull our coach out once a month, when we are not on the road, and run both the generator and the Aqua Hot. I will also turn on the TV and satellite dish and exercise them as well.

A national or area rally is good places to have your unit serviced.

Herman

[monk]

Jana0623,

I also have a 2016 40 AH with the same problem. This has been happening since we purchased it in June 2016.  Did you ever get it fixed? I just discovered that there are air bubbles in the return fuel line, apparently getting in around the fuel filter. I bypassed the filter today and no bubbles now. I will run it a few days again to see what happens then let you know. Lots of people are having this problem and no one seems to have found the reason.

 

[manholt]

As Herman said.  Needs service once per year, run once or more per month!  Mine has never given me any problems, it is there both on diesel and electric when I need it. Up until yesterday, I ran it on diesel for 9 days none stop!  not even a hic up, just make sure you have enough diesel...I now show 56 gallons left on a 150 gallon tank!  Currently in a 80' x 120' garage, set at 70 degrees. The electric side is on to give me hot water.

[wildebill308]

34 minutes ago, manholt said:

As Herman said.  Needs service once per year, run once or more per month!  Mine has never given me any problems, it is there both on diesel and electric when I need it. Up until yesterday, I ran it on diesel for 9 days none stop!  not even a hic up, just make sure you have enough diesel...I now show 56 gallons left on a 150 gallon tank!  Currently in a 80' x 120' garage, set at 70 degrees. The electric side is on to give me hot water.

Are you back at Pipe Creek?

Bill

[hermanmullins]

Bill,

Remember, Carl has 3 homes, Burnet, Galveston and Pipe Creek. It is a toss up where he spend the most time.   

Herman

[wildebill308]

Herman you are right. Has he given up on Nacogdoches? 

Bill

Nacogdoches

[jleamont]

Monk, you bypassed the fuel filter? So perform a careful inspection of the line connections, remove the filter and inspect the O-rings. Either way replace the filter, lube the o-rings and seals prior to installing. 

[manholt]

Joe, your absolutely right, I overlooked that part.  That could get expensive!

WBill, Herman.  Yes, I'm in Pipe Creek, getting a expensive disaster taken care of that was MHT Tech fault. Having to re wire all my Silverleaf and replace 2 burned out camera's!   We are all very surprised as MHT is a Gold Star Silverleaf Tech center!  The African American (PC) could not find his....with direction, map, 3 hands and a flashlight!  Brett will probably delet this and put me on a looong time out!!!!

[richard5933]

If you just bought the coach recently then unless the previous owner kept good records you won't really know the maintenance history of the Aqua Hot unit. These units work great, but they do require maintenance on a pretty tight schedule to replace things like filters and the nozzle.

There is a guy named Lloyd De Gerald who is an authorized repair guy for these things. If you call him tomorrow maybe he can walk you through things on the phone. He worked with me to get my Webasto up and running and seems like a straight shooter. http://lloyddegerald.com/

You should also talk to him (or whoever you finally get to help you service the unit) about getting a few spares on hand for when you need them.

[manholt]

I have mine serviced at the same time that oil change is due...once per year or 16,000 miles, which ever comes first. 

[flyingtrout]

I have a 2015 Fleetwood Providence.  I have the 400D Aqua Hot.  On the electric side, hot water and electric heat to Zone 3 work fine.  When engaging the Burner Switch, light comes on, blower comes on, however, I do not hear ignitors, no smoke from the exhaust and no smell of diesel. 
After about 30 seconds the light goes out on the Burner Switch.  I would surmise, that with no ignition (popping sound) and/or smell of diesel, this may be electrical.  I am getting ready to take to dealer, any last minute suggestions.  Tank is full, there are no red lights on the panel.

 

Thanks 

[dickandlois]

17 minutes ago, flyingtrout said:

I have a 2015 Fleetwood Providence.  I have the 400D Aqua Hot.  On the electric side, hot water and electric heat to Zone 3 work fine.  When engaging the Burner Switch, light comes on, blower comes on, however, I do not hear ignitors, no smoke from the exhaust and no smell of diesel. 
After about 30 seconds the light goes out on the Burner Switch.  I would surmise, that with no ignition (popping sound) and/or smell of diesel, this may be electrical.  I am getting ready to take to dealer, any last minute suggestions.  Tank is full, there are no red lights on the panel.

 

Thanks 

Think the first item would be a good cleaning, Fuel filter(s) Igniter checked. 

Rich.

,

[manholt]

If your to low on the coolant fluid, it will not start or run on diesel.  check the level of your white reservoir tank, it's probably mounted on the wall above or behind your 400 box.

[hermanmullins]

Carl, you are so right. With all the room in the water bay that is where you would thank that there would be a nice convenient place for it. Not on my Dynasty, mine is in the fuel bay on the passenger side. Go figure.

Herman 

[wildebill308]

They just had to replace my AH transfer fluid tank it is on the back of the engine compartment and the diesel filter is in front beside the generator. It looks like there would have been plenty of room in the compartment the AH is in.

Bill

[jleamont]

Flyingtrout, I’ve got to agree with Rich. How long since the unit was serviced?

Herman, got to love that location For the filter! That access door on ours didn’t open either by the factory design, riveted closed. I made a latch mechanism for ours. 

[djkunasz]

HYDRO-HOT unit will not ignite. Based on the description,  maybe someone has a clue....Model HHe 200-09E Serial number HE 06-1969.  Just serviced unit with fuel  nozzle and cleaning. (Fuel filter previously changed) Did NOT test just before service but it ran well about three weeks prior. PROBLEM: Unit will not ignite. INDICATIONS: Initiate start sequence by turning on Diesel rocker switch. The Green light by switch comes ON, blower starts. No ignition. No smell of diesel fuel from exhaust . Control panel shows no red lights but shows Green LED's in Diesel Burner Status, Pump #3, and Heating status. After about 20 to 25 seconds, green light in interior rocker switch  turns off. All the illuminated LED's go OFF on control panel -- blower runs for another 2.to 3 minutes, and cuts off. New diesel fuel. NOTE: Seems control panel and diesel switch lites go OFF  at the same time that there should be ignition and fuel started. This unit does NOT have a safety switch on the cover. The red light  indicating low coolant warning is NOT on. Fuel tank is full. Thanks for any advice.

[wildebill308]

Welcome to the forum. I don't know and I have a Oasis they are similar but. Have you tried pushing the "reset" button on the unit?

Bill

 

[five]

Try asking your question on Roger Berke's AH forum:  http://www.forum.rvhydronicheaterrepair.com/