First cycle ok, but second cycle not reflowing

[phonoplug1]

Another issue I have found is that when using the oven continuously, the first time everything reflows fine, but the second and subsequent times the boards come out not fully reflowed. This seems to be because the temp sensors inside do not cool as fast as the rest of the oven, so subsequent runs do not achieve as higher board surface temperature as the sensors are effectively 'pre heated'.

The solution I found is to:

a) Always do a dummy run first with the oven empty, so that all cycles will then be the same, and

b) After each run cool the oven to a known temperature before running again. I do this with a 12" desk fan, sat face down into the drawer/pointing into the oven, with the oven set to 'cool' so its internal fan still runs below 70 degrees. It normally takes about 5 minutes to get the on-screen temperature to 30 degrees or lower, after which its ready to go again.