Never had much trouble with the HydroHot, so though I read member issues here, I’m admittedly low on memory as to this one.
After repainting the chassis side of the corroded tray with POR-15 and putting new maintenance-free Interstate batteries in (the 14 year-old ones still read 12.5 volts), I decided that before humidity rose prior to today’s projected heavy rains, I also should run the HydroHot and genset. Overdue was the regular 20-30 minute exercise I try to give them while the coach is “stored” here by the house. The HH wouldn’t start up, so I tried the usual off, pause, and back on reset. Still nothing. So I checked the panel lamps in its bay and found the Low Fluid one illuminated red.
Must’ve been just long term evaporation to somewhere. The coach has been “stored” for almost 4 years. Yup, the expansion tank was below the Cold line, so I added 50/50 boiler mix to that line. But then, there is no sensor on that plastic tank like on the CAT’s, so I’m thinking this ain’t as simple as that. I figure, okay, the fluid level sensor must be in the main tank. I try removing the radiator cap, figuring to add fluid until the lamp goes out or turns green. Cap loosens but won’t come off. Hmmm.
If all else fails, read instructions. From that I get I have to find a way to pump fluid in through the drain valve! Really? I obviously can’t get fluid sucked back from the expansion tank without first heating and cooling the main tank, and of course it won’t start to begin with. So is my only option to rig a manual or electric pump and plastic tube to the drain valve? Or is there a trick to getting the radiator cap off? There appears to be no release gap it’s locking flanges can be turned to. Can I attach a tube to the drain valve, hold it up higher than the unit’s top, and funnel in fluid to raise the tank level?
The HydroHot model is HHE200-09E. While awaiting any responses here, I’ll go dredge up that specific model’s documents from the AquaHot library, because the manuals I’ve seen so far have varying or insufficient commentary troubleshooting this problem, or relate to other models.
I suppose it could be a gunked up float switch, but the low expansion tank level would seem to counter that notion. I could jumper the switch’s two circuit board wires on the controller and bypass the switch to likely power up the unit, but if the fluid is actually low in the main tank, that would be ill-advised I would think.
Joel