automatic generator startup?

My aqua hot has one exhaust pipe coming out, about 2" in diameter, not two as the OP has described. That said, if I leave the diesel switch on at night it will fire up for a few minutes. To prevent that, I leave the electric switch on and the diesel one off at night. If my batteries draw down, the generator will come on with the autostart but it will run for about 30 minutes to charge the batteries back up, not only for a few minutes...without more information, we're only guessing anyway.....wonder why the OP didn't just go over and ask...:h.....Dennis

Bob & Ann wrote:
.....It operates through a separate diesel engine that kicks on and off at random......

There is no diesel engine in a Aqua Hot system. It is a diesel fire boiler that works on the same principle as the propane water heater. The water cools down, the boiler fires up to reheat the water

It sounds like it is an Aqua Hot system which heats the water, heats the coach as well as the floor. It operates through a separate diesel engine that kicks on and off at random. The regular generator can be set to kick on if the batteries get low or if the coach gets too warm. Setting it to kick on when it gets too warm is typically used if it is parked with pets in it. We do not have the Aqua hot but we have a friend that has it in his Allegro Bus

The gen normally would not come on several times during the night, even if it was on auto start. The noise you heard could have been the burner firing up on the Aqua Hot.

Mr.Mark wrote:
Mr. Herefishy, I'm thinking it was the Aqua-Hot as it could come on periodically if left on. Or, did the motorhome have basement air?

Do you recall the brand of motorhome? That could tell us a lot about the options it may have.

MM.

Bingo. Not sure I understand the noise issue though.

Mr. Herefishy, I'm thinking it was the Aqua-Hot as it could come on periodically if left on. Or, did the motorhome have basement air?

Do you recall the brand of motorhome? That could tell us a lot about the options it may have.

MM.

No...it's a feature that only the most expensive units have...that is changing however with new technology that lets you add an auto start feature for a few hundred bucks...

I wouldn't say the "typical" motorhome has a generator auto start, but many of the newer ones do. Having said that the ones that do have an auto start feature also have a control panel that allows the owner to program the generator not to start during "quiet hours".

In all cases that I'm aware of the generator will only self start if there is no shore power and the batteries go below a level set at the control panel, or the temperature inside the coach goes above a preset level and the air conditioner needs to run.

Many higher end motorhomes are also equipped with an Aqua Hot or other similar heating system. If it was a cold night you might have been hearing it start and run.