Hi Gang - (Admin - Posted this here, as most Hydro Hots are in Class A's and this board gets the most traffic.)
We've have a Hydro Hot and have had an intermittent problem with the diesel firing up for about 2 1/2 years now.
Normal yearly service has been done since we bought the coach used, ~6 years ago now.
I've had help from Roger Berke's Forum, always nice to respond in ways a layman like I can understand
He has referred me to two different tech's over the years. And I've had the following done by them, and then also a repeat by a third tech I called while in Yuma.
1) Taken a part and cleaned the combustion chamber, and reset the points (I call them points, as they spark to ignite the diesel.
2) Had the points replaced, just because we still had problems.
3) Had the little laser gismo light reader replace twice.
4) Again, normal yearly service by competent techs.
I've had two items suggested that may still be causing this problem of intermittent firing of the diesel:
1) I'll call them 'brushes', as it was described as a motor that needs to turn. Possible we have a bad spot, and by intermittent luck, the motor stops on one of these bad spots(?). Though I wonder if 'It's a bad spot.' - why does it then sometimes 'Start up?'.
2) Control Board could be going out.
Both of these are pretty high ticket items, but form the money I've tossed at this replacing items that were less expensive, and more likely to cause the problem - I think I could have had a new Control Board by now
I want to assure you, that two out of the three tech's that were involved, did methodical as possible trouble shooting. Watching them, the both checked the same things, but in different sequences. They also both gave me their opinions on what 'It could be, and then suggested a path of repair.'. (I mention this, as I do feel that two out of these three tech's were as capable as their reputations and referrals indicated. The third came and looked at what I asked him to, validated it was a bad part (One that I had bought used from a previous tech. As it was all that he had with him, and he sold it to me at 20% of what new part would have cost.), and replaced it with a new one.
But here we are again, 5-6 months more of intermittent diesel firing. Will work great 3 to 5 times, kicking back on multiple times as needed based upon hot water demands. But then maybe that same day, or the next week, I'll hit the diesel switch. It will make the start up noise, but not fire, and then the light above the door will go out again. You can hear the unit still running to clear the chamber of any fuel, just as it does when the burner shuts down after reaching temperature. I've learned to wait a good hour or longer after this, to let the chamber dry out all the way, before trying it again.
Sometimes it will not fire back up for two to three days. Then magically, it fires again, and always smokes heavily for the first good 'burn off' of accumulated dried diesel. I'll run hot water in the coach when it has fired up for the first time again, to let it run good and long and burn off the gunk.
OK - That's my long wandering story. How about it? Any of you ever have intermittent diesel firing problems on a Hydro/Aqua Hot? Would appreciate the unusual ones that you may have found, as it might point us in the right direction
Best to all,