I am cocooned in a room with the only method of washing hands my Triton Handwasher. It has started acting up. Occasionally when I start it up it heats the water, but now it rarely heats the water - rarely switches on. I removed the unit and re-installed everything and it worked for about 24 hours and then problem recurred, cold water Can anyone suggest what might be going wrong. The flow of water is the same as it always was. The unit is old (was installed in 1993). But I need it working.