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Technical Support / Re: Aqua Hot suddenly not heating?
« Last post by Joel Ashley on Today at 12:11:32 AM »Hydronics float switch photo and tank drain location photo.
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Technical Support / Re: Aqua Hot suddenly not heating?
« Last post by Joel Ashley on April 30, 2026, 01:43:59 AM »To Fred's comments:
The float switch in my HydroHot wore/broke a few years ago. It wasn't something I could dig out of the top of the tank, but if you lower the coolant level to below the switch port, you can remove the switch (the float may not be with it if it broke off). Replacement switch/float assemblies, as I recall, are "rare" but available from certain vendors. My replacement was an improved version as I recall, and less likely to "disintegrate" and or the float leak.
The job was messy, but I finagled a drain line from the drain port down and out an existing nearby hole in the bay floor. Sans that it could've been worse. I probably followed instructions proffered on a YouTube video, but recall my configuration was slightly different, requiring some common sense thinking. I know I was concerned about the missing float part sashaying around inside the tank, but ultimately decided, after failed fishing attempts through the top, that it wouldn't interfere with operations. It's imperative that everything be kept clean, like around the top cap/port and the switch port. You don't want dirt or debris getting in the tank. Properly done, you can reuse the fluid you have to drain to get below the switch port.
It was a matter of getting just the right deep socket as I remember (finally found at Autozone) - and I had to modify it to accommodate the new switch's wires, carefully balled up and stuffed inside undamaged while turning the wrench. Then it was just a matter of hooking up a couple of wires.
I think a person can jumper a couple points on the board and bypass the float switch until you have time to do the repair or get it to a service facility. I apologize for my dim and aged memory, but others here may offer further details. And somewhere I think I have pix of my fix that I'll try to add.
Joel
The float switch in my HydroHot wore/broke a few years ago. It wasn't something I could dig out of the top of the tank, but if you lower the coolant level to below the switch port, you can remove the switch (the float may not be with it if it broke off). Replacement switch/float assemblies, as I recall, are "rare" but available from certain vendors. My replacement was an improved version as I recall, and less likely to "disintegrate" and or the float leak.
The job was messy, but I finagled a drain line from the drain port down and out an existing nearby hole in the bay floor. Sans that it could've been worse. I probably followed instructions proffered on a YouTube video, but recall my configuration was slightly different, requiring some common sense thinking. I know I was concerned about the missing float part sashaying around inside the tank, but ultimately decided, after failed fishing attempts through the top, that it wouldn't interfere with operations. It's imperative that everything be kept clean, like around the top cap/port and the switch port. You don't want dirt or debris getting in the tank. Properly done, you can reuse the fluid you have to drain to get below the switch port.
It was a matter of getting just the right deep socket as I remember (finally found at Autozone) - and I had to modify it to accommodate the new switch's wires, carefully balled up and stuffed inside undamaged while turning the wrench. Then it was just a matter of hooking up a couple of wires.
I think a person can jumper a couple points on the board and bypass the float switch until you have time to do the repair or get it to a service facility. I apologize for my dim and aged memory, but others here may offer further details. And somewhere I think I have pix of my fix that I'll try to add.
Joel
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Technical Support / Re: Aqua Hot suddenly not heating?
« Last post by Roger Milne on April 29, 2026, 07:43:49 PM »Thanks for info. I’ll look into it and see if that helps.
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Technical Support / Re: Aqua Hot suddenly not heating?
« Last post by Fred Brooks on April 29, 2026, 02:02:15 AM » Roger,
One of the possibilities could be the "float switch" inside the coolant reservoir. If it has detected low coolant, it will give you the symptoms you are experiencing. Turn off the electric and let the coolant cool off and remove the radiator cap. If the coolant is not right there in the neck, add coolant. Hope this helps, Fred
One of the possibilities could be the "float switch" inside the coolant reservoir. If it has detected low coolant, it will give you the symptoms you are experiencing. Turn off the electric and let the coolant cool off and remove the radiator cap. If the coolant is not right there in the neck, add coolant. Hope this helps, Fred
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Technical Support / Aqua Hot suddenly not heating?
« Last post by Roger Milne on April 29, 2026, 12:48:48 AM »So the Aqua Hot suddenly quit running on the Diesel Burner side a couple days ago and I found the return hose from the expansion tank to the pressure cap had split and drained the expansion tank. So repaired that and topped up the tank with about 1/2 gal of Propylene Glycol.
All indicators on the control module are showing green, but when I flip the kitchen panel diesel switch to "on", the indicator comes and the burner lights off, but then turns off and goes through its purge / cool down cycle and after that the indicator light in the kitchen panel goes out. The switch is still in the "on" position and the #3 Stir pump still runs as indicated on the control panel, until I switch the off in the kitchen.
I have checked the expansion tank since running it and it seems to have drawn in about 1/4 of a gal based on the fact I filled it to the "hot" line and it now shows half way full between the Cold and Hot marks.
There's no Red indications on any of the system monitor lights, so I don't know if I have air in the system or if something else is going on. I'm currently away from the RV for the next 14 days and my wife can use the electric element for hot water, but I wanted to see if I maybe missed something or what direction of troubleshooting I need to take when I get home.
All indicators on the control module are showing green, but when I flip the kitchen panel diesel switch to "on", the indicator comes and the burner lights off, but then turns off and goes through its purge / cool down cycle and after that the indicator light in the kitchen panel goes out. The switch is still in the "on" position and the #3 Stir pump still runs as indicated on the control panel, until I switch the off in the kitchen.
I have checked the expansion tank since running it and it seems to have drawn in about 1/4 of a gal based on the fact I filled it to the "hot" line and it now shows half way full between the Cold and Hot marks.
There's no Red indications on any of the system monitor lights, so I don't know if I have air in the system or if something else is going on. I'm currently away from the RV for the next 14 days and my wife can use the electric element for hot water, but I wanted to see if I maybe missed something or what direction of troubleshooting I need to take when I get home.
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Technical Support / Re: Immediate starter engagement
« Last post by Fred Brooks on April 28, 2026, 04:14:15 PM » Here is a picture of the Trigger Solenoid on the back of the battery box. I am not sure why Beaver decided to hide this solenoid in such a place that is so hard to find. Please follow Eric's diagnosis as it covers all the details to evaluate your issue. Fred
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Technical Support / Re: Immediate starter engagement
« Last post by Eric Maclean Co-Admin on April 28, 2026, 02:47:30 PM »Brian
Check at the primary start / trigger solenoid ( the one in the back of the battery bay ) to see if you are getting a start signal headed to the solenoid on the starter.
You may want to use a jumper wire to bridge between the two larger connections on that primary /trigger solenoid to verify whether or not the new starter will crank
In order for the starter to operate the transmission control module ( TCM) must be active and showing the transmission in neutral to allow a start trigger signal to pass ,that signal is the sent to the rear run control switch where it is passed on to the start trigger solenoid . The start trigger solenoid is used as a relay to operate the starter solenoid.
The trigger solenoid will have two larger terminals one of these will be hot all the time with battery voltage , and the other large terminal will be connected directly to the starter solenoid to activate the starter. By jumping across these two large terminals the starter should operate if it doesn't you have a wiring issue or a faulty starter.
If on the other hand it does operate the starter by connecting the two larger terminals it would indicate the trigger solenoid is not doing its job .
The trigger solenoid is an isolated ground solenoid meaning the coil that operates it is isolated from the case or internal connections,
This type of solenoid has two smaller terminals one of which must be connected to a good ground and the other is the trigger wire.
If the solenoid does not operate check the two terminals to see if you are getting a good ground on one and a trigger voltage on the other when the key is turned to the start position.
The trigger signal for that solenoid comes from the rear run switch ( which can sometimes be problematic)
How ever if as you state you get an audible click at the trigger solenoid and the starter does not operate.
First check that you have 12 volts at one of the trigger solenoid larger connections if so try to jump a cross those two large terminals if it doesn't crank.
Check your wiring at the starter it is possible you have inadvertently connected one or more of the smaller ground or feed wires to the wrong terminal on the back of the starter when you replaced it.
On the other hand if your audible click is at the starter it is possible the starter solenoid/ pinion depth is set too deep and not allowing the starter solenoid to complete the starter circuit. ( Bad starter rebuild )
Page 18 of the 1996 Patriot wiring diagram in the coach assist library shows the starter wiring circuit to help you understand the power path .
Eric
Check at the primary start / trigger solenoid ( the one in the back of the battery bay ) to see if you are getting a start signal headed to the solenoid on the starter.
You may want to use a jumper wire to bridge between the two larger connections on that primary /trigger solenoid to verify whether or not the new starter will crank
In order for the starter to operate the transmission control module ( TCM) must be active and showing the transmission in neutral to allow a start trigger signal to pass ,that signal is the sent to the rear run control switch where it is passed on to the start trigger solenoid . The start trigger solenoid is used as a relay to operate the starter solenoid.
The trigger solenoid will have two larger terminals one of these will be hot all the time with battery voltage , and the other large terminal will be connected directly to the starter solenoid to activate the starter. By jumping across these two large terminals the starter should operate if it doesn't you have a wiring issue or a faulty starter.
If on the other hand it does operate the starter by connecting the two larger terminals it would indicate the trigger solenoid is not doing its job .
The trigger solenoid is an isolated ground solenoid meaning the coil that operates it is isolated from the case or internal connections,
This type of solenoid has two smaller terminals one of which must be connected to a good ground and the other is the trigger wire.
If the solenoid does not operate check the two terminals to see if you are getting a good ground on one and a trigger voltage on the other when the key is turned to the start position.
The trigger signal for that solenoid comes from the rear run switch ( which can sometimes be problematic)
How ever if as you state you get an audible click at the trigger solenoid and the starter does not operate.
First check that you have 12 volts at one of the trigger solenoid larger connections if so try to jump a cross those two large terminals if it doesn't crank.
Check your wiring at the starter it is possible you have inadvertently connected one or more of the smaller ground or feed wires to the wrong terminal on the back of the starter when you replaced it.
On the other hand if your audible click is at the starter it is possible the starter solenoid/ pinion depth is set too deep and not allowing the starter solenoid to complete the starter circuit. ( Bad starter rebuild )
Page 18 of the 1996 Patriot wiring diagram in the coach assist library shows the starter wiring circuit to help you understand the power path .
Eric
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Technical Support / Re: Immediate starter engagement
« Last post by Frank Bergamo on April 28, 2026, 03:02:58 AM »Also, while you are at it, make sure all battery cables are clean and tight!
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Technical Support / Re: Immediate starter engagement
« Last post by Joel Ashley on April 28, 2026, 02:44:31 AM »After all the work, make sure your chassis batteries are still fully charged, and/or use the boost switch on the dash to have the house set assist.
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Technical Support / Re: Immediate starter engagement
« Last post by Frank Bergamo on April 28, 2026, 01:19:58 AM »Where is the click coming from when you turn the key? The starter, ignition solenoid, key switch???