Aqua Hot Not Producing Heat

[Will Procter]

we can hear the Aqua Hot blower come on. The floor heat had come on a few times during previous nights but the electric heating coil evidently had the water hot enough so the Aqua Hot furnace did not kick in. This morning the vent fans ran for so long I thought something may be wrong. I held my hands in front of the vents inside and the air was barely warm so I suspected the Aqua Hot boiler was not working correctly. I went outside and there was dark diesel exhaust smoke and actually some unburned fuel dripping from the exhaust. The Aqua Hot was running, just did not seem to heat the water. I have all of the manuals and my guess at this time is it may be the fuel nozzle. Need some opinions and trouble shooting help guys.

Will