Posted by Harold Kestenholz - Hydronic Network on April 16, 2001 at 10:35:41:
In Reply to: Buzzing boiler posted by Jeff on April 14, 2001 at 13:08:53:
You have eleiminated one of the causes by measuring the voltage. A relay can buzz when the hold-in voltage is too low. In this case you seem to have enough. Another cause of buzzing in a new relay is the position the relay sits. The position holds the weight of the clapper just enough to resist the hold-in magnetism. A chancey way to eliminate the noise is to bring the mounting arm toward the coil. As this is difficult to do precisely, it can be overkill. Sometimes mounting the relay on its back will help. Another possibility is to use another brand of relay; if this can be done without violating listings. It is not an easy problem to solve.