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Old 10-05-2020, 03:17 AM   #1
Junior Member
Brand: Thor Motor Coach
Model: Tuscany 45AT
State: Ohio
Posts: 12
THOR #16882
Aqua-Hot & FireFly

We have a 400D Aqua-Hot in the motorhome and it is working fine with the exception of no heat from the Aqua-Hot. Plenty of hot water. The burner and electric element is working fine.
The Aqua-Hot electronic controller board has been replaced with the same result, no activity on the motorhome side of the board. There is a unit labelled Firefly G5 Controller Module between the Firefly and the Aqua-Hot Electronic Controller Board. I can see the LEDs light up on the G5 controller when heat is requested to the various zones but no lights on the Aqua-Hot controller board or voltage to the heat exchangers in the motorhome. I have searched for any information on this G5 controller to no avail, even looking on FireFly Integration web site revealed nothing.
Any ideas would be appreciated!


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Old 10-05-2020, 11:28 AM   #2
Senior Member
Brand: Thor Motor Coach
Model: Tuscany 42GX
State: Missouri
Posts: 727
THOR #9178
I have a unit prior to the Firefly so no help there

Has to be that the indicated output doesn’t connect to the Aquahot input

Does your zone 2 pump come on when system heat is selected?

Feel the pex line at the Aquahot and it should be 120 degrees or higher

Zone 2 is used as the stir pump since the 400D units don't have one that is dedicated

That should happen if the system is in the heat mode and the heat exchanger is hot
Never confuse education with intelligence
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Old 10-05-2020, 11:29 AM   #3
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Brand: Thor Motor Coach
Model: 2020 Magnitude SV34
State: Florida
Posts: 3,339
THOR #12751
I'm not familiar with the Aqua-Hot system but I have experience with the FireFly system.

I would call or e-mail FireFly and explain your situation.

Contact | Firefly Integrations

I have used their Technical Support on two occasions and they have helped me diagnose and resolve issues.

You could need a firmware update or you could have a hardware problem. They should be able to help you diagnose your problem.

My system has a G7 Main Control board that had to be replaced because I was having issues with it properly controlling my two A/C units. There would be times only the A/C fans would run even though the thermostat called for cooling and there were times only the compressor would run and not the fans. I had the G7 controller replaced in June under warranty and I have not had any issues since.
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