well, i spent this morning bypassing the bypass valve with some copper tube, and then flushed out the whole coolant system till it was spangly clean. an then got all the air out of it.
an it still dosnt work!
i dont know what else it could be now, my heaters are really poor, looking round the site ive tried flushing system, the valve and the thermostat is fine (i think).

anyone got any other ideas?
