Aquastat Pellet Boiller What Setting

ScotL said:

All I know is my PB105 has no aquastat at all on it. When the oil boiler needs heat (for hot water or heat), its aquastat turns on the PB105 circulator. The down side is, the oil boiler is not an automatic backup. I have to leave it switched off and turn it on manually when I want to use it. But, the PB105 is not circulating its hot water when it's not needed.

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I'm thinking that, if you set the low temp dial on the oil boiler 10-15* lower than the low setting on the pellet boiler controller,in case of a pellet boiler failure, the oil boiler would fire heating the water to whatever the high setting is on the control, this way the oil boiler would only run when the pellet boiler failed.

I've never had the ESP loosen up. Maybe you can find a slightly larger screw to hold it in tighter.
As for bags per day, I'm not sure. I've been having my boy fill the stove every 3 or 4 days. I'm pretty sure if I ask him, he'll have no clue how many he put in.

Chris04626 said:

ok i had the aqustat set at 130 pb not running, i turned it down to 100 and you can hear something start running if i turn it back up the noise stops

Thoughts on what this is doing? Im Assuming its the turning the circulator on???

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Using a screwdriver, place the blade on the circulator motor, the handle to your ear, turn the aquastat dial up or down listening to hear the circulator start or stop, confirming if in fact that this aquastat controls the circulator. Using the same method testing to see if the circulator is running, with the pellet boiler temp above 130*, the aquastat dial set at 130*, the circulator should be running until the temp drops below 130*in the pellet boiler.

Using the same method testing to see if the circulator is running, with the pellet boiler temp above 130*, the aquastat dial set at 130*, the circulator should be running until the temp drops below 130*in the pellet boiler.

• Description for Honeywell L4006B1007

Switching Action SPST, contacts make on temperature rise

The above info is from the link that you posted as to what aquastat that you have. Remove the cover on your aquastat, tell me what the number is on the inside of the cover, I think it might be a L4006A, the link that you posted is to a L4006B. The link below is to the L4006A. If it's a L4006A, turn the dial to 200* to see if it will run the circulator

http://www.supplyhouse.com/Honeywel...stat-100-240F-range-5F-Differential-4587000-p

Chris04626 said:

the model number i got was stamped on the end of the aquastat

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Please tell me what that complete number is or pull the cover on the aquastat, tell me what number is on the bottom of the cover.

It depends on if you have it wired as a cold start or if the boilers are maintaining the teno between the two set points. I have mine set for cold start which means the pellet boiler comes on and the circulator valve opens when there is a call from my thermostat. I have the oil boiler wired to an aquastat and a timer delay so the the oil boiler will automatically kick in if the water temp on hasn't reached 150 after a set period (I have it set at 2 hours during burn season and 1 min when I have the pellet boiler shut down for the summer and there is a call for hot water)

I also have a high temp aquastat hired onto the outlet of the pellet boiler and a 10 min delay to continue to run the circulator for after there is no longer a call from the upstairs thermostat.

Obviously disregard if you are maintaining temp within your boilers but even so you might just need a delay timer that you adjust so the your oil boiler doesn't kick in the same time as your pellets.

Hope this helps!

Ben

Chris04626 said:

ok pulled the cover it says

Type L4006B Switch closes on temp rise

I turned it to 130 again and went back later and circulator was still off, turned down to 100 came on, seems it only runs if you turn it down to 100

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The specs mention that the L4006B, switch closes on temp rise, meaning that the circulator will start when the temp of the water is above the dial set point. If the dial setpoint was on lets say 130*, the circulator would not run until the water temp in the boiler was above 130*. As you have mentioned, the circulator will run, set at 100*, it should, as long as the pellet boiler is above 100*, at a setpoint of 130*, it should also run as long as the pellet boiler temp is above this setpoint. My guess is the aquastat is faulty. I believe the installer intent was to have this circulator only run when the pellet boiler temp was above the setpoint of this aquastat.

Chris04626 said:

ok checked an hour later PB is off is at 160 ob is at 150 circulator not running. turned it to 100 it started right up

So should i keep it at 100 and have it run most of the time or keep it higher?

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I don't know what other devices, if any, that could be wired into the control for that circulator so I would set it at 100* because you mentioned that it will not run on any other dial setting, this will insure that hot water will be pumped to the oil boiler.It will result in a few more pellets burned because of heat loss through the piping, pipe insulation would help this a little. If that aquastat was functioning as designed, if the temp dial was set on 160* or whatever temp setting, it would not run the circulator until the pellet boiler water temp was higher than the dial setting, it won't shut off until the temp was lower than the dial setting. The bottom line is, even if that model aquastat was functioning as designed, that circulator would probably be running all the time.

I see no reason to replace it because if you purchase the same aquastat, adjust the dial to say140*, the circulator will probably run all the time anyway during the heating season. If you want control of the circulator not running all the time, the aquastat that I've mentioned in one of my posts would need to be used, plus, this aquastat would have to be relocated to the top of the oil boiler to sense the temp instead of the top of the pellet boiler, to start and stop the circulator at whatever setpoint.