[an error occurred while processing this directive]
Posted by HeatPro on October 31, 2005 at 16:08:39:
In Reply to: continuous running circulator posted by wendell on October 31, 2005 at 10:50:19:
Running with no flow doesn't bother the usual low-head direct drive cartridge circulators, It might affect a shaft-drive circulator, depending on the mode. To discuss situations intelligently, you need to provide make and model of machinery, as there is no single model used by everyone in the world, and there are characteristics unique to different manufacturer's models.
Either there is flow when the zone valves are closed, or not. The same situation could occur with zone valves on the supplies. The noise is more likely a check valve or something loose in the pipes, unless you can hear a rattle with a stethescope at the circulator.
Many circulators do not do well 'unloaded' that is, not having some resistance. Usually circulators do better running constantly, rather than starting and stopping. My last home circulator lasted 20 years running constantly.