Limited out

danger

I have a 15000 sq ft nursing home with a Weil Mclain MGB-5 boiler and 4 zones of 1" fin tube radiation controlled by wall t-stat and zone valves.Last spring the boiler inspector requested that a manual reset high limit be installed and also a manual reset low water cutoff. We removed the combo boiler control and limit and installed the requested controls along with a "smart" boiler control with outdoor reset.The limit switch has now become the most important switch on the boiler as it reqires constant attention.It has opened on numerous occasions during all types of temperatures from -22 to +39. The system requires a water temp of 190 to keep up at design temp. (-11) We have the adjustable limit set at 210. Any suggestions ?

Maynard

High Limit

We Set The Manual Reset Aquastat @ 240F To Avoid The Nusance Calls You Are Having.

danger

How hot is TOO HOT ?

Matt_67

240

we also use 240 for the manual reset

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RonWHC

Did you

leave an operating aquastat in the circuit?