Originally Posted by davo54
I changed the aquahot nozzle on my 42qd a couple of months ago. The cord reel isn't really in the way. It's just awkward getting to the burner coming in from the side but not hard. I bought a set of cheap hose clamps on amazon to clamp the 2 fuel lines. You'll want to use a flare nut wrench to remove the fuel lines. Since we have hard fuel lines to the burner, the burner comes out for service. You'll also need the hose clamps for changing the filter underneath the coach.
Adding to davo54, there is an "L" shaped access cover that comes off the top and right side (facing the cord reel). The entire burner comes out with it's attached hard fuel lines. You will have to disconnect the controller clamped to the side of the burner can as well. The burner is clamped in place with hinged bolts (10mm) and use a long extension to get to them. As davo54 said, clamp the fuel lines
There is a 118 page Aquahot Service Manual:
AHE-450-DE4_Service_Manual_REV_E.pdf available, with good pics and troubleshooting.
Awkward, but once you've done it, the whole thing changing nozzle, setting ignition gap, cleaning burner, probably take less than 1-1.5 hours start to finish.