Community Forums

TOJOS · 08-12-2008, 12:29 PM

Need Help.....
My Hydro-Hot is inop. I had a full tank of fuel and hooked up to city water. I opened the fill/cap on top and it was full. The overflow tank was between the lines. I did notice a red lite on the electronic controller panel (forward side) of the Hydro-Hot identifying "Low Tank Level Cut Off" was on. The unit did work on eletric at first but when I turned it to diesel nothing happened and would not operate when I switched back to electric only again. Suggestions Please.... Tom

TOJOS
2005 Alpine Limited 40' FDTS

TOJOS · 08-12-2008, 12:29 PM

Need Help.....
My Hydro-Hot is inop. I had a full tank of fuel and hooked up to city water. I opened the fill/cap on top and it was full. The overflow tank was between the lines. I did notice a red lite on the electronic controller panel (forward side) of the Hydro-Hot identifying "Low Tank Level Cut Off" was on. The unit did work on eletric at first but when I turned it to diesel nothing happened and would not operate when I switched back to electric only again. Suggestions Please.... Tom

TOJOS
2005 Alpine Limited 40' FDTS

Wil Rathke · 08-12-2008, 12:58 PM

I had this happen to our coach recently. I found that the level switch was bad and I replaced it which fixed the problem. If you want to replace it yourself read on. Fortunately, I found a new switch at a large RV dealer in the Dallas area close to where we were parked. The float switch connects to terminals 15 & 16 on the right side of the control panel with red wires. You will have to remove the panel cover to get to the terminal strip ( 4 screws). This will expose the circuit board. Remove the red wires and check them with an ohmmeter. The meter should read near 0 ohms. If it reads high of open, the switch is bad. You can bypass the switch with a short jumper wire to get going. The switch is not difficult to replace. You will have to drain the fluid down to the switch level. The new switch used a different size socket than the old one so be sure you have the right tools before starting. The factory suggested using both Teflon and pipe thread sealer.

Renipladlo · 08-12-2008, 01:10 PM

Turn it off, let it sit for 30 seconds, then turn the diesel burner back on, this resets the system. If that does not fix it, bad sensor someplace.

jerry davis · 08-12-2008, 02:29 PM

Same thing happened with mine. It was the float switch. Got a new one from the factory that was much better than the plastic one that was originally installed. Fairly easy to install.

In the meantime simply jump the wires at the control panel with a paper clip.

BigSkyBob · 08-12-2008, 05:57 PM

I also got a new float switch from the factory and replaced it. My temp sensor also went south and had to be replaced. But you can do this with the proper size deep well sockets. You will need deep well sockets so you have room for the attached wires.

TOJOS · 08-14-2008, 02:52 AM

Bob, Do you recall how long it took to replace the float switch in your Hydro-Hot Unit? Tom

EngineerMike · 08-14-2008, 11:00 AM

The pre-2007 units won't reset w/out using the reset button on the control board. On our 06 I carried a small stick on a hook on the control board for pushing the reset button (there is a small hole in the cover plate, and the reset is a small switch; push it & you will feel it click; its like the reboot button you need for microsoft). One time, for reasons known only to the HHot gremlins, my unit wouldn't operate; something to do w/voltage. One click & it worked fine.

Wil Rathke · 08-14-2008, 12:06 PM

If you can't find a small enough stick, try the red spray tube from a WD-40 can or something similar. I taped mine to one of the wiring harnesses.

Renipladlo · 08-14-2008, 07:40 PM

Speaking of Hydro Hot units, and especially mine. It's again scheduled for a master technician to re-check the unit to determine why we don't have hot water. My belief is the mixing valve is stuck closed. This will require the removal of the unit from the coach, as getting to it will require a bean pole person, no bigger than olive (you remember-popeye and olive) to get in there and replace it. I will post the results on Sunday evening. OBTW, it going to be over 100 in Hood River, OR where the repair is going to take place. I want to get started early around 8, we might have it done by noon if we work fast.

dshogman · 08-16-2008, 06:01 AM

More on low-level check light - seems this thing always quits on Saturday mornings. Reading the above, looks like my problem. But what's happening is that every once in a while the light flickers to off and the burner starts for a few seconds.
So, does this sound the switch failing?? I'll do the ohnmeter test and then jumper the switch as I know there's plenty of fluid.
Comments or advice please.....
Thanks.

Wil Rathke · 08-16-2008, 06:24 AM

When I replaced my float switch I found that the plastic body was somewhat deteriorated (sp?) and stuck. I think your switch may be intermittant and stuck in the down position but sometimes freeing up and floating up to the closed switch mode. By the way, this switch is position sensitive - it has to be installed with the arrow pointing up.

dshogman · 08-16-2008, 06:47 AM

Follow-up - the ohmmeter isn't where it's supposed to be down below, so just detached 15 & 16 and jumpered with a paper clip. Now it works OK. Will call Monday morning and have them send me the switch.
Funny thing is, when I got back from Texas in March, after all the trouble I had while there, both of the other switches had to be replaced.

Renipladlo · 08-16-2008, 09:09 PM

So all know, today we had our HH looked into. One thing was determined the control board was not shutting off the LTOC=Low Temperature cutoff switch and starting the stir pump. So the board was replaced. In addition, the tech was able to squeeze back in the compartment and turn the Mixing Valve several times in both directions and then setting it to 4. We will use the coach in normal outdoor temps later in the week, and see if this fixed it. We are currently on the backside of a major heat wave with temps over 100+ degrees. Once this hot weather moves off, starting tomorrow, things will be back to normal, and we can see if it works correctly. If it does, and the little lady wants the tech too, we can ask him to turn it down to 2.5.