Aqua-Hot circulator pump "cycling" with power off

[Mike Shumack]

I have a 2005 Beaver with the Aqua-Hot AHE-100-04S.

With the power off (Coach Power switch off) and the Engine Off, I hear a clicking noise coming from the Aqua-Hot. The Aqua-Hot panel in the basement compartment has no lit lights in this (off) mode.

I removed the cover and see the Circulator Pump #2 is clicking (it appears that is trying to rotate - the internal impeller just jumps back and forth a little). The other two pumps do not do this. I disconnected the power wire to that pump for now.

I downloaded the Owners, Installation, and Service manuals but there is nothing mentioned on this condition.
I will try to run the entire system later this week (furnace mode) to see if the cycling stops after it is run for a while (in case something (contact switch?) is just stuck due to sitting)

Has anyone seen this - any idea what it could be?
PS. I posted this question on the iRV2>Monaco forum too. Hopefully someone has seen this before.

[David T. Richelderfer]

Is your coach plugged into shore power?  Is the AquaHot electric element water heater turned ON?

Our coach is the 02S model and does not have a control panel.  Ours has a diesel burner ON/OFF switch over the living room couch and a breaker in the main 110v panel to turn ON/OFF the electric heating element.  These functions (diesel burning and electric element water heating) are separate functions - meaning one or both, or neither, can be ON/OFF.

[Mike Shumack]

I am plugged into Shore power (but only 120V 20A supply).
I'm not sure about your other question. I'll check when I get home later. I had the "Coach Power" switch Off (I now know not to do that) and nothing inside is lighted. I don't know what the position of the "Electric" switch is (On or Off) for the Aqua-Hot. I believe this is switch bank located under the counter in the galley.

UPDATE: Checked with wife, the Aqua-Hot electric switch is Off.
I'll run the furnace for all zones (which should run all circulator pumps) when I get home and then see if the #2 circulator pump is still acting up afterwards.

[Steve Huber Co-Admin]

I have a similar situation in my Hydro Hot. Experts say it is due to a bad control board, which makes sense as the voltage signal for the pump comes directly from the board. My solution was to install a switch in the voltage line to the pump. I turn it off when the HH is not being used. Just have to remember to turn it on when I use it.
Steve

[Stan Simpson]

I'm not an expert, but IIRC, the Aqua Hot needs 12V to start the system. If you have the Salesman switch (power off switch) off, you don't have 12V power. Perhaps the clicks are from the system trying to start due to the thermostat, but no power. Just an idea.