FIEM Incubator problems

[Wolds7]

I have a FIEM smart 24, near new, which I have had two very dissapointing hatches from. After the last hatch, where of the 18 eggs, 5 were infertile, 6 hatched, 1 was ditched due to infection, and 6 developed but then failed to progress past 6-9 days, I decided to purchase 4 Independant thermometers to try and troubleshoot the issue. I discovered that the machine, though displaying one temperature (37.7 Celsius) was actually fluctuating somewhat dramatically between 36.8 and 39,though all be it for breif periods. It seems incapable of holding a correct temperature and will, instead, spend most it's time flicking between small variations and, occasionally, having a big jump to 38.5 degrees and above.

What I'm hoping to understand is whether anybody thinks that such variation could be the reason as to why a number of eggs ceased to develop? The first hatch was 24 eggs and I had a success of 6... 25% is a bit of a stretch.

Any assistance would be appreciated.

 

[CluckEmUp]

From my understanding those values are completely fine. Fluctuations aren't necessarily bad. Hotter temperatures will cause the eggs to develop faster than colder temperatures, that can negatively impact the development.. but.. if it hasn't gone above 39C, I don't think there should be too many issues.

To be honest it could just be the eggs themselves. Unhealthy chickens may not lay the best of eggs.

Maybe someone more experienced can pitch in though.

 

[Altairsky]

Does your FIEM smart have a fan? I had catastrophic temperature variations on mine but it's an old model with no fan, no egg turner and no digital display (see photo on https://www.backyardchickens.com/threads/help-fixing-an-old-incubator.1616174/#post-27631269 )
I'm planning to add a fan and I purchased 4 independent thermometers, so on next attempt I see if I manage to stabilize the temperatures somehow.