alde heater noise

What noise exactly are you experiencing? There's two kinds that have been discussed in other threads - A gurgling from the fluid as it passes thru the overflow tank and a roaring noise.
1 - Can usually be toned down by adjust the flow of the pump
2 - Usually only occures when camping at higher altitudes 8k or higher. No real fix for this yet.

Trailsnail said:

is the alde heater supposed to be very loud. No way to use it at night as it makes so much vibration noise loud on the outside also.

Something else I'd do is pull the outside plastic cover on the Alde vent from the side of the trailer and check to see if you have any insects that have built a nest inside that area.  I noticed a rumble in mine earlier in the spring of this year and that was suggested by the factory as mud wasps often find there way in this area.  I have since installed a screen across the openings of my Alde and hope that this ends that threat.