Hoffman 150 controller does not operate

Clark Kalkowski

This is the 2nd season on this new boiler installation. We replaced the old converted coal burning steam boiler with a new Burnham 160,000 btu unit and added a condensate tank and pump to handle the excess water of the system. Condensate pump is activated when the boiler needs water by the Hoffman 150 controller. Why does the controller fail to work when the water is dirty in the boiler? It is not because the float is hanging up inside the case because as soon as the fire shuts off because of low water the float will drop and turn on the pump to refill the boiler. After completely flushing out the boiler and the condensate tank so the water is clear again the controller works like it is suppose to. What's going on? Any help would be appreciated.

Unknown

My thoughts

The water stays high in the MM 150 in the same way that the water rises in the returns of a system without a check valve when the water is dirty. The steam that can't break the surface causes this, somehow. I've seen it, but the science of it escapes me.

Noel

Clark Kalkowski

Thanks for correcting me on the name of the controller my mind was thinking McDonald Miller but my fingers didn't