Is the water running?.

dbarck2000

I recently had my 1930s hot water gravity system converted to a modern system with a circulator.

Now, when the circulator is running, I hear a high pitched sound that is similar to a partially open water valve (such as a toilet that is running). This is driving me a little crazy!

Is there any way to eliminate or reduce this noise?

More info about my system:
My house is a two story 1930s duplex with CI radiators (hot water). There are 4 loops (2 loops in each floor). Each floor has about 8 radiators. The new system has one boiler with one circulator and a zone valve for each floor. The circulator is a Grunfos Alpha2 15 - set to Auto.

mattmia2

Is this a system with separate supply and return mains or an early monoflow/diverter tee type system where there is only one main that the supply and return for the radiators tap off of the same pipe?

dbarck2000

There are separate supply and return mains.

mattmia2

You can try running the circulator at one of the lower speed fixed settings. There may be orifice plates in the supply unions of the upper radiators to balance between the first and second floors. That system doesn't need a lot of flow but the auto adapt setting might think it is connected to some huge system rather than a small system with huge pipes and be trying to flow as much as it can.

dbarck2000

Thanks I'll give it a try.