Community Forums

castrol · 11-24-2015, 11:01 AM

1997 Signature. Aqua Hot heating system.

I'm still working on this thing. Trying to figure it out.

I replaced the bulb in the aqua hot switch to get it working and help me troubleshoot.

Boiler works when only the water heater turns on. When I start the genny the boiler shuts off and the light on the switch goes out.

Sliding the furnace thermostat switches on turns on the baseboard fans but only cold air comes out. Cycling through the the AC thermostat gives me the option for "heat strip" which is nice. But no furnace option. Am I missing something? I've been adding a lot of coolant over the last few weeks trying to get the level to stay in the I guess it's an overflow bottle. I seem to have that part done.

What's my next step? I just feel like I'm not 100% certain on the operation and function of this machinery.

Dennis4809 · 11-24-2015, 11:55 AM

I'd start by filling via the radiator cap vs the overflow. Once the system is full, focus on one thing at a time. Does it heat using the electric element? Can you get hot water at the sink or some faucet? If that part works, you can switch to the diesel function. First thing is to perform an annual service. New fuel filter, new nozzle and clean the combustion chamber. Turn on the diesel function switch. Listen for the igniter, does the burner start? Are the fans running? Only after you get this done can you worry about heat to the coach. Check the status lights. Should be green. If boiler is hot and zone pumps are working, PEX lines should feel hot. If not, no circulation. Check each zone. If the pump is spinning and still no circulation, there's a check valve just after each zone pump. Tap smartly as they may be stuck.

When all else fails, contact Roger Burke at the Aqua Hot forum. He knows all. Be sure to give him the model number of your heater.
Aqua-Hot Questions

castrol · 11-24-2015, 01:39 PM

Quote:

Originally Posted by Dennis4809

I'd start by filling via the radiator cap vs the overflow. Once the system is full, focus on one thing at a time. Does it heat using the electric element? Can you get hot water at the sink or some faucet? If that part works, you can switch to the diesel function. First thing is to perform an annual service. New fuel filter, new nozzle and clean the combustion chamber. Turn on the diesel function switch. Listen for the igniter, does the burner start? Are the fans running? Only after you get this done can you worry about heat to the coach. Check the status lights. Should be green. If boiler is hot and zone pumps are working, PEX lines should feel hot. If not, no circulation. Check each zone. If the pump is spinning and still no circulation, there's a check valve just after each zone pump. Tap smartly as they may be stuck.

When all else fails, contact Roger Burke at the Aqua Hot forum. He knows all. Be sure to give him the model number of your heater.
Aqua-Hot Questions

Diesel burner works. Heats the water quickly and well. I don't believe the electric element is working. We also have hot water after traveling so the engine is heating the water in the aqua hot as well.

I'll see if I can contact Roger. Thanks!

Outbound · 11-24-2015, 04:32 PM

Sounds like stuck check valves

Ken

2002 Monaco Executive

steined · 11-24-2015, 04:34 PM

Try tapping the check valves on the top of the aqua hot with a large screw driver and hammer. If your fans for the furnace are engaging, and you have hot water, I'd be that the check valves are stuck. I just had this happen to me in one of the zones on my 2000 Dynasty.

I had to jiggle the hose to get the check valve unstuck, tapping with wrench wasn't enough force.

castrol · 11-24-2015, 05:12 PM

Are there any diagrams on how these things are laid out and how they function? It would be neat to have an idea of all the systems.

shiggs68 · 11-24-2015, 06:45 PM

All the various AuqaHot model manuals are online at their web site. Just Google search your model number.

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TravellingRVDoctor, LLC

castrol · 11-27-2015, 04:03 PM

I took th access panel off and started doing some investigating. I was getting no burner action until I tapped on the control box. As soon as I tapped the control box the burner and fan fired on.

The burner stayed on for about 5 minutes, maybe a little less but the longer it stayed on, the more the control box would click. Sounds like a relay kicking on and off. When it would do that, the fan sound would change. The longer it burned the more spradic and excited the clicking became.

It got to a point where it sounded almost chaotic and the burner turned off and the fan continued to run for another couple of minutes.

Cycling the switch lit the burner again, but since the water was already pretty hot, the chaotic clicking of the control box was pretty there at the start. It burned for another 30 seconds or so and kicked off again.

Sounds like I could have a control box issue?

shiggs68 · 11-27-2015, 04:28 PM

If the burner works like a Atwood or Suburban furnace, burner shutdown with the blower continuing to run is an indication that the flame was not sensed. The board then reenables the spark ignition trying to light (the clicking sound). Is there a thermocouple or flame sensor rod?

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TravellingRVDoctor, LLC

castrol · 12-03-2015, 08:53 PM

Good news is two of the three furnace pumps work as they should. The one that sounds funny apparently doesn't pump any fluid. Turns out there was a water valve that was in the off position. Turning that on allowed the warm water to flow through the pumps. So I've got heat to the mid and rear of the coach.

That is, when the aqua hot actually burns.

I've still got to do a full service on it and get it cleaned up and figure out why the electric side doesn't work. I still believe I'm going to have a problem with the webasto control box. I'll save that for last though. For now I can make it function enough by tapping the control box to get some hot water on our trips. Big disassembly and maintenance coming soon.

Coma · 12-05-2015, 06:15 AM

Sporadic sounds coming from the control box is a sure sigh its toast. There are new, used and rebuilt options. It should run for 10-20 seconds on start and 2 minutes on shut down, before and after flame.

If the electric element was run without enough fluid it will fail immediately. However, it could be just fuse or relay that has failed. Roger Burkes forum is wealth of information.