Honeywell 8124

chuck172 said:

I'm trying to set up my Honeywell 8124L 1003 triple duty Aquastat to cold start.

I need to disconnect the low limit.

Click to expand...

I guess I don't quite know what you mean by 'disconnect the low limit' to make it 'cold start'. Give us another clue!

chuck172 said:

the boiler will maintain the low temperature even in the summertime. It's designed for tankless heaters. That way the boiler is always ready to give hot water. I know there is a way to disable this feature and make the control cold start enabled. I asked this question'at the wall, but they got into one of their usual pompous attitudes.

Click to expand...

Sorry, you've got the wrong guy when it comes to avoiding pompous. ;-)

It's the wire from the low limit aquastat NC terminal B to ZR that feeds the input to the high limit aquastat when the boiler temperature is below the low limit DHW setpoint.

So just need to release the wire from the low limit B terminal by pushing in the push-to-release thingy on the upper B terminal and working the wire free. (As opposed to the lower B terminal since apparently some convention forced them into having two different B terminals on the face of the same subassembly, not that I'm complaining, I normally figure it's best to follow convention wherever it takes me.)

(I'm a little worried because although the L8124L is a little different I believe the aquastat subassembly is the same for all of them, so I don't see how disabling the low limit would be different for the 'L' as opposed to the other variants.)

The exposed wire will be hot when the boiler is running, so a wire-nut to cover it would be nice.

And cut those other pompous guys some slack, you'd be pompous too if you woke up one day and found yourself in a position to charge $450 for a $69 part, plus travel, plus minimum service charge!

Cheers --ewd

chuck172 said:

Thanks Eliot
I keep getting this advice on the wall:
Remove the wire from the "B" terminal on the R-W-B side and jump out "R" and "W". In all cases upon completion make sure it shuts off on hi - limit.
I can't figure out what they mean by jump out R and W. They won't explain.

Click to expand...

They must mean pull the R and W wires and wire-nut them together, or put jam in another wire from R to W to 'jump out' the NO contacts on the low limit aquastat, which would completely eliminate all functions of the low limit aquastat.

As near as I can figure the 'triple' in triple aquastat comes from the three functions it provides: Shut off the burner on high limit, maintain the boiler temperature in the low limit range when there is no call for heat, and disable the circulator outputs C1 and C2 when the low limit is not satisfied.

Here in this boiler room we can assume you don't want to eliminate the disable-circulator-on-low-boiler-temp function because we can guess more easily what you're up to, but over there they might more easily have assumed that you wanted to eliminate all trace of the low limit aquastat.

chuck172 said:

Thanks Eliot
I keep getting this advice on the wall:
Remove the wire from the "B" terminal on the R-W-B side and jump out "R" and "W". In all cases upon completion make sure it shuts off on hi - limit.
I can't figure out what they mean by jump out R and W. They won't explain.

Click to expand...

They must mean pull the R and W wires and wire-nut them together, or put jam in another wire from R to W to 'jump out' the NO contacts on the low limit aquastat, which would completely eliminate all functions of the low limit aquastat.

As near as I can figure the 'triple' in triple aquastat comes from the three functions it provides: Shut off the burner on high limit, maintain the boiler temperature in the low limit range when there is no call for heat, and disable the circulator outputs C1 and C2 when the low limit is not satisfied.

Here in this boiler room we can assume you don't want to eliminate the disable-circulator-on-low-boiler-temp function because we can guess more easily what you're up to, but over there they might more easily have assumed that you wanted to eliminate all trace of the low limit aquastat.

And by all means verify that the burner deactivates on high limit!

chuck172 said:

Like the above picture?

Click to expand...

Bit of a rat's nest there, but it looks like they've got B tied to W, which would have the effect of jumping out the R-W [del]NC[/del] make that NO aquastat path. If you are using C1 to control a circulator, I would think you would want to take advantage of the don't-run-the-circulator-until-low-limit-is-satisfied feature. I would think all you want is to disable maintain-temperature feature. For that you need to pull just the B wire and wire-nut the exposed copper all by its lonesome and leave the R and W wiring alone.

--ewd

To make it simple pull and cap the blue wire.