Biomass 40 controller shuts off - frustrated

This is my second year using a Biomass40 with 500 gallons of storage. I have always used the following settings:

thermostat - 195
pump - 170
hysteris - 4
fd--
fb30

Starting at the end of last year the unit would shut down automatically at start up and "fuel" would be seen on the controller. This occurred within about an hour after starting the unit, very seasoned wood, clean boiler, clean chimney, gasification, blue flame, etc. I was told that by setting fd at - - that it would not shut down at start up. The problem continued and ultimately I received a new controller (under warranty) this year). The same problem is happening again with a new contoller. I should also point out that the boiler is not reaching the 195 thermostat setting so the fb30 is not to blame. That setting is working fine.

Again, I am still using the settings above, the boiler has a dedicated circuit of power, all of these settings worked for 6 months, but am frustrated that the system is shutting down automatically still. Today for example, the boiler and tank were at 140 and I started it, had a nice bed of coals, put in very seasoned wood. All was well, the system was getting up to 170, the pump would turn on and then shut off when the boiler temp dropped below 166. Then after some period of time the unit shuts down and "fuel" is on the controller. I have to hit stop and start and then the system will be fine for the duration of the night.

As you can imagine, it is very frustrating to have the unit shut down on its own. Has anyone experienced this. Anyone know how to correct.

Thanks,
Andrew

What did you set your fd setting at to make the problem go away? Thanks

I will try that. I can't imagine there are any drawbacks. I will let you know if it works. Thanks again.

Thank you for the comments. I tried the fd 4 hour setting and it is not shutting down. When it gets to 195 and eventually can't get back to 195 within 60 minutes (fb60) it shuts down fine.

Still curious about the fd-- setting. I was told that this overrides the fd so it won't shut down during the start up. I tested this setting once with no wood and the fan ran for hours without shutting down, but if I try it with a burn it shuts down at random times (usually within an hour). I am happy that I have it working without shutting down. No hurry, but if anyone has any insight into the fd-- setting I would appreciate it.