i have a monoflame burner on thermacon boiler which when fired up will run for some minutes then stop firing, but before locking out will fire up again. i have replaced magic eye solonoid coil and control box. every few days or so it will go to lockout but will fire up on resetting the control box. i have been in touch with manufacturers and they suggested disconnecting balanced flue hose to see if combustion air was being compromised. any ideas would be gratefully received.
