Question

Hi, I have a Morco water heater that won't heat my water. The pilot light is lighting and when I turn on the hot water tap the burner ignites and heats the water for a few moments and then goes luke warm/cold. Would you be able to tell me what could be wrong, I have been told that possibly it could be lime?

Answer

The problem could be water pressure or, as has been suggested to you, the heat exchanger could be suffering from lime deposits that are preventing a sufficient flow of water. Alternatively the diaphragm in the water control valve could be damaged such that the water pressure is unable to open the gas valve fully.