Central Heating Pump Electrical Resistance

[Jura]

I have a client with a Halstead Hero which intermitently locks out. I suspect the pump may be toiling and causing overheating. I tested the resistance across the windings which read 279 ohms. I have read that a reading above 200 ohms suggests the pump may not be circulating effectively. Any thoughts?

 

[mountainman]

Where did you read that?

 

[Jura]

I read in John Reginald's "Combi Boilers Fault Finding and Repair" that 120 - 200 ohms = motor windings OK so I deduced that higher than 200 ohms may be a problem.

 

[mountainman]

Ah!
Pump may be running slow and causing overheat lockout but I don't think that testing the resistance of the windings will tell you with any certainty.
Pumps do sometimes run slow but can be hard to diagnose until you bite the bullet, replace pump and hey presto - everything is working fine again.