Question

it appears that the cascade mk2 is leaking i have taken it out of the van but cannot see any obvious sign of a leak any ideas where it could be please thanks, Les .

Answer

If the heater has suffered frost damage then the likely leak will be at the point where the tank joins the heat exchanger. This is generally not easy to repair as replacement tanks are not available. The other possibilities for leaks are at the cold water inlet connection or at the hot water outlet connection and these connections should be unscrewed from the heater to check their condition.