[cwl1979]

third from right marked with the W

[whited44]

third from right marked with the W

I was never the sharpest tool in the shed. Thank you..  I’ll report back

[whited44]

Something else I noticed is that this plug to the brain of the Aqua hot it not hooked up. It looks like it’s marked “pump + / -“ and then there are some wires butted together that have similar colors.  Does this have anything to do with the pumps not running??  Applying 12 volts to the white wire didn’t seem to do anything

[Trainer]

Tne new 300 901 control unit has pig tail plugs vs the three plugs mounted into the Botton of older control units. Your "B" and "C" plugs are plugged in correctly. Since you have an Aqua Hot heater and do not have a Webasto Heate Exchanger, which are used in some Prevost conversions, you do not need the "A" plug. So, the "S" plug just sits there getting your attention.

[whited44]

I jumped the red and white wire to try to get the pump to kick on with both thermostats to no avail.. I do have 12 volts at the red wire

[Jack Houpe]

Check fuses on Aqua hot?

[Trainer]

Call me. Rudy. 7 one 3. 8 one 8. 3234

[whited44]

Call me.  Rudy. 7 one 3. 8 one 8. 3234

shout out to Rudy!!  I talked to him today. I was able to confirm all 3 pumps do run, I did need to order 1 cube relay.  So I think I have 2 problems.  The check valves are stuck ( I tried sacking them with the back of a screw driver with no luck) and I think my thermostats are junk. Can anyone recommend a decent replacement??  

thank you guys

[Richard]

Why do you think the tstats are junk? Have you measured the outputs with a voltmeter?

I am all for you upgrading tstats, but a few minutes of diagnostics may save you from replacing the tstats only to discover there is some other issue.

Coleman makes a direct replacement. Coleman-Mach 6535A336

Micro Aire makes a fancy WI-FI capable model.

[whited44]

Why do you think the tstats are junk? Have you measured the outputs with a voltmeter?

I am all for you upgrading tstats, but a few minutes of diagnostics may save you from replacing the tstats only to discover there is some other issue.

Coleman makes a direct replacement. Coleman-Mach 6535A336

Micro Aire makes a fancy WI-FI capable model.

The switches are worn out. So from fan, to off, to heat, to cool you can’t really tell what position it’s in.  Also after about 3 minutes after I set the mode to either heat or AC it changes back to “actual”.