ravenheat ls80 t overheat problems.

[scarfeuk]

hi all, new to industry and having trouble with a ravenheat white star ls80 t, think its the mk1 as thereis no reset on control panel and only two buttons. Originally called out to repair leak on ch pipework, failed push fit reducer. The system had been loosing pressure for approx 12 months prior to leak bringing down ceiling. The last gas engineer simply told the tennants to run the ch with the filling loop turned on.

I fixed leak and went on my way. Called back next day because boiler has flashing red l.e.d indicating overheating. So far i have replaced the overheat stat, flushed system, looked like mud coming out of radiators, removed and cleaned heat exchanger, checked high and low burner pressures. Pump appears o.k. Have made radiator in bathroom the by-pass, removed and cleaned t.r.v's.

Sytem now runs for approx 1-2 hours and then trips overheat.

Oh and the ch system is also on micro bore.

Any suggestions greatly recieved as my head now hurts from banging it against the wall.

thanks.

 

[wards]

poor ciculation/airlock in system would be my prognosis.

 

[scarfeuk]

have bled system, all 5 radiators are red hot. Could there be aproblem the pump when it reaches a certain temp. Also i was considering a powerflush but would the push fit connectors stand up to this, seeing as 1 has already failed?