Aquahot 375 owners (2010 Revolution)

[rdalcanto]

When the diesel burner first turns on, there is this repetitive, metal expanding type noise. I don't know how else to describe it. Unfortunately, the exhaust tubing for the muffler runs under the bedroom and transmits the noise, which makes it hard to sleep. The noise goes away after a few minutes once everything gets hot, even if the burner keeps running. Here is a video of the noise that I uploaded to youtube.
Aquahot, who has no authorized service technicians in the area, watched the video and tried to tell me it is normal for the Becket burner used in the AH375. Anyone with a model 375 care to comment?

[Cat320]

We have a 450D, don't recall that noise. Have you tried here: RV Hydronic Heater Repair - Home

[rdalcanto]

Yes. I have emailed Roger a lot. He has been VERY helpful and generous with his time. Unfortunately, we are not going to cross paths. Also, he is less familiar with the Bennett burner, since it is not used very often.

[JMonroe]

Hmmm. We had a lot of issues with our Aqua Hot immediately after taking delivery of the coach and some strange noises came along with them. Eventually the unit was serviced by someone from Aqua Hot during one of our visits to Decatur and we've had no further issues since. I'll notice it running if I'm outside, not that it's obnoxious, but you can hear it, but not so much if we're in the coach.

[Dick_Wins]

Also have a 2010 Rev with the 375 Aquahot. As Jay said I only hear pump and burner noise. No expansion type noises.

[rdalcanto]

Dick_Wins. With your 375, how even is the burner noise "jet" sound when yours is running. Does it vary, or is it very constant?

Thanks,
Rick

[Dick_Wins]

It sounds very similar to the full size Becket burner I had in my house, The blower comes on for a 20 sec or so then the fuel pump comes on and ignites. It runs smoothly and evenly on till the cut off temp is reached. Fuel shuts off but blower continues to run to purge chamber. sometimes the burner will restart before the blower shuts off.
I think you will find that the air/fuel ratio is critical on these units. When I first got the coach the burner had a hard time starting. Too much air. The burner is set at the factory for 5600 ft altitude. Kept blowing out the flame when starting resulting in a lot of extra fuel. Since I was at 100 ft altitude (Florida) the factory tech support had me readjust the air intake opening CCW to about 1/4 open. It was in the middle of the adj set at the red mark. The burner then started right up and ran smooth and clean. No smoke. The other problem I had was the ignition points were not properly set. Too close. This resulted in a carbon short across the points. re-set to factory specs and unit running fine for the last 6 months.
When this unit is serviced, the tech should check the burn efficiency and pump pressure. Essentially this unit should have the same service as a full size home burner. Not just change the nozzle and filter.

Dick