To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.
The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Need to contact us? Visit

Failing Aquastat?

T_ROT_RO Member Posts: 1
I have a 20 year old weil-mclean 68V with tankless coil, 4 zones, circulators, Tjernlund PV, Honeywell L8124A,C aquastat.

A couple times this past week my boiler temp was 120 degrees or less before it fired. My settings are 160, 180, 10 diff. Is my lo switch failing? Is there a way to test it? The only thing I've done is run them around a little. This aquastat is ~5 years old.

Edit: add'l info this morning at 400 am house pretty cold when wife got up. no hot water in shower, when I got downstairs boiler was running and at about 130 by then. temps were in low 20's wouldn't have a call for heat started the burner?

Also, I have been thinking about installing an electric hot water heater, if I do so I assume I could go with a different type aquastat that only has a Hi setpoint?



  • billtwocasebilltwocase Member Posts: 2,385
    power vent

    How is it wired? Sounds like they are using B-1, and the fan prover is not always, or delaying the power supply to the primary control. 
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!