PB105 control panel blinking 7 times

I purchased a house that came with a PB105 pellet boiler and an LP boiler, I have not been able to get the pellet boiler to work, it just keeps blinking 7 times. The manual says it has something to do with the overheating and to shut the power off and turn it back on to reset. Well I can't understand how it can overheat when it hasn't even been running, the valves to it are turned off so the water in it is room temperature, and it doesn't matter how long I leave the power off, when I turn it back on it just keeps blinking 7 times. I've called two Harman dealers in the area and they say they've never worked on one, they will research it and get back to me, but they never do. Anyone have any ideas? Would I need to replace the aquastat, or the control board?
Thanks

katman said:

Have you tried opening the valves so water can run through the boiler? Is the boiler starting at all? Have you given it a good cleaning--if not, do that and make sure to clean the area where the fines collect and also clean the probe in the exhaust. Also, make sure the aquastat probe is fully inserted in the well and turn the circuit breaker off in addition to the off on the unit.

Click to expand...

I've opened the valves long enough to get water flowing through the bottom and out the top, there is a spigot in the top connection I let water run into a bucket. I didn't leave them open. I wanted to heat the water first. I've cleaned everything the manual says to clean. I can go through the test procedure and here the auger working and the exhaust fan running, but when I turn the controls to turn it on I just get the seven blinks and I here nothing else happening. I've never had it running so I don't know if it makes any noises while the igniter is working to start the pellets, so not sure if that's working or not. I have turned the circuit breaker off, doesn't seem to make a difference. I have not messed with the aquastat probe, I can check that tonight. Thanks.

I purchased a new Aquastat sensor cable and installed it, there was no spring like other have talked about, any way after installing the new aquastat cable the stove started, I'm heating with it , and the 7 blinks are gone. Thanks.