PB105 Correct Operation?

[scooter]

I am wondering if I have a problem with my PB105?
Settings: OAT connected out side, Min 160°, Max 180°, Feed Rate 5, Outside Temp 16°F, T-stats set at 68°,
The boiler heats up until it reaches 180° and stays there with a varying flame and feed rate meaning the auger will run for different time periods.

The auger runs anywhere between the times listed below.
on 1 sec - off 12 sec
on 3 sec - off 12 sec
0n 5 sec - off 10 sec (It never stops)

I thought with the OAT connected out side. The PB105 boiler as it reaches the max temp of 165° based on a 15° out side temp would slow the feed rate to anticipate hitting the max temp. Then I thought it would basically coast and not feed anymore pellets until it gets close to the MIN setting.

With the boiler at 180°! If I turn the main switch off for a few seconds and back on the feeder stops feeding until it gets close to the low setting. When it reaches the max temp again it just keeps feeding at the time frames listed above. (It never stops on is own or allows the boiler water temp to drop)

Is there a problem with my boiler controls or am I wrong with how it is supposed to operate?

 

[bruceM]

Hi

I am new to this I am still trying to plumb my 105 up the right way but i believe the outside temp sensor starts dropping boiler temp by 1degree for every degree above 20 farenheight.

Bruce in Vermont

 

[AndrewChurchill]

It drops the max temp by 1 degree for every degree above 0F, not 20F.

 

[scooter]

So with the OAT connected out side. The PB105 boiler as it reaches the max temp of 165° based on a 15° out side temp would slow the feed rate to anticipate hitting the max temp. Then I thought it would basically coast and not feed anymore pellets until it gets close to the MIN setting. Mine seems to just stay at max temp!

 

[AndrewChurchill]

Your min and max temps are only 20 degrees apart so if PB over shoots by 10 or 15 degrees then it's always going to be hovering around 180.

Another thought is several PB users have experienced accuracy problems with their gauges so you may be experiencing a similar issue.

 

[wil lanfear]

scooter,
I think the issue you are having with pellets feeding in when the boiler is up to temp is with the circulator between the PB and OB running all the time creates some heat loss.This is the reason I installed an aquastat in the OB, adjusted to about 10* less than the high setting of the PB. The aquastat shuts the circulator down prior to the PB reaching the high setting. To confirm if this maybe the reason, turn this circulator off, close a valve either on the return or supply of the PB and see if the PB aquastat will get satisfied, stopping the feeding of fuel.

Now, my thoughts on the OAT, for me, heating DHW with the PB tankless heater, it does nothing for me. My DHW demand, lets say at 30* outside ambient temp, needs to have water temp in the boiler higher than 150*.

 

[scooter]

Thanks Wil,
I'll give it a try tonight, Should I have installed a flow check on the on one of the paralleled pipes between the two boilers?

I made the adjustments we talked about the other day' I'll let you know the results in a few days.

 

[scooter]

Good call Wil!!
I did what you said, turned off the circ as it was reaching high temp and closed a valve. It went to sleep like a baby!! No Auger action, Burn pot went black. I need to get an aquastat tomorrow. Can you suggest what kind to buy?