Can a circulator pump turn on an indirect water heater?
If you have an indirect water heater installed and a single circulator pump serving all of your heating (and water heater tank) zones, then a call for heat at any thermostat OR a drop in temperature in the indirect water heater will turn on the circulator.
How does the low switch control the circulator?
The low switch indirectly controls the heating circulator by locking out (keeping off) the circulator pump assembly if the boiler temperature drops into the low range. Check valves control circulator flow or flow rate and may be used to balance heating zone flow or heat output.
What causes circulator to intermittently turn off heat?
Next I’d check for a bad circulator control relay or possibly a thermostat wire that is intermittently shorting together. Occasionally a bad thermostat can also cause intermittent on-off calls for heat that can lead to odd circulator behavior. A second set of possibilities might be a circulator pump that is binding or failing.
When does a circulator pump switch on 120VAC?
When the circulator relay is switching on 120VAC to the circulator pump itself we should see 120VAC at the power terminals at the circulator pump. Watch out: exposing or touching live electrical wiring connections can shock or kill you. If you do not know how to make these tests safely don’t try it: call for help from a trained professional.
Next I’d check for a bad circulator control relay or possibly a thermostat wire that is intermittently shorting together. Occasionally a bad thermostat can also cause intermittent on-off calls for heat that can lead to odd circulator behavior. A second set of possibilities might be a circulator pump that is binding or failing.
When the circulator relay is switching on 120VAC to the circulator pump itself we should see 120VAC at the power terminals at the circulator pump. Watch out: exposing or touching live electrical wiring connections can shock or kill you. If you do not know how to make these tests safely don’t try it: call for help from a trained professional.
Why is my circulator not pushing hot water?
If just a few feet from the circulator’s output side the pipes are cold, most-likely the circulator is not pushing hot water. (Also see our air bound heating warning at the end of these notes). Listen to the heating pipes: Close a zone service valve part-way.
Why is my circulator not running in the Hot Zone?
After leaving the thermostat and circulator relay “on” – calling for heat – overnight, the circulator motor itself was very hot, but the zone piping on the outlet side of the circulator, just a few feet away, was cool. The circulator motor was not able to run.
