Hunting shower

[AndyJ]

After an 2 bar Easiboost shower pump sprang a leak, I've replaced it with a Salamander RSP50 connected to a thermostatic shower unit (which was there when the easiboost failed).

After fitting, on full hot - no problem. On full cold, the water is "pulsing", or hunting as I think folk in the know call it. I'm pretty sure that I've gotten all the air out - any tricks here?

Aside from a faulty pump (unlikely I guess - more likely something my doing is wrong) any suggestions ?

 

[kevgrim]

disconnect cold supply on inlet side of pump, then run full bore into large bucket this will indicate any supply problem, make sure any isolation valves are of the full bore type not those tiny penny sort that are turned with a screw driver.also check filters on inlet, check in header tank for any floating debris, this does sound a bit strange because it's usually the hot which gives problems sometimes due to dhw temperiture to high, or wrongly positioned dhw draw off. regards.