Update.....Think i am a wally!
Pump back installed and everything running again....i think i have found the issue....or none issue!
After reading the ML700 (Balboa) manual, i noticed a statement that says the circulation pump may switch off for a period of 30 minutes if the water temperature is 1.5 degrees above the set temp. I think what i did last week was lower the set temp while i added the swirl away and had the jets running as it wasnt necessary to maintain the temp anymore.....of course this would make the pump stop!
The following day when i tried it, the was water was still circa 30 degrees so still above the lowered set temp! hence ther motor would run for 1 minute and then stop again.
However it wasnt a wasted effort taking the circ pump out, i found that the plinth that the pump sits on was rotten so made a new one and the seals for the heater and pump where 100% knackered and leaking.....hence i have changed these now.
Still....the circ pump runs very very hot.....this must be normal as i believe the pump has a thermal cut out?!? However does anyone know how hot a pump should run under normal conditions? I can then close this thread...