Can't have shower!

[fumi]

PLEASE help!
I'm using The boiler's a Rinnai BU150-047(00) on a boat.

and when I'm using hot water,boiler goes off...
so I have shower with cold water...so I have to get out of the shower room,and have to switch it on again and again and...

I don't know why.is it because of water pressure or gas?

if anyone know about this,please help!!

Thanks!!

[htg engineer]

Thermocouple ? dirty pilot ?

If the pilot is dirty or the injector is blocked, when the boiler is on the pilot flame may be lifting off the thermocouple.

or

The boiler is over-heating.


htg