Is it a Saxon brand hot water system ?
As ones like Rheem / Dux just use a big tank of water which an element heats up, and then when you turn the hot water tap on, you get this heated water.
Saxon and some other companies use a different type. Basically they use a tank (usually smaller than he equivalent capacity of the other type). and inside this tank of water is a coil of copper pipe. So the water in the coil of pipe, never actually comes into contact with the water in the tank
The element heats up the water in the tank, and then when you turn the tap on, it draws water though the copper pipe, and the heat gets transferred though and you have hot water.
But the water in the outside tank, is only filled up when the water in the coils expands and cracks open a small valve. And because the outside tank is vented to the atmosphere, over time the water level drops, which basically means the capacity of the unit drops. Sometimes this can reduce the capacity by 50% or more.
Luckily its easy to fix. Basically there should be a little lever on the side of the valve in question. Someone just needs to lift this lever, and they should hear water flowing though the pipes. and they just need to hold it up until water starts to flow over the overflow pipe. This could take a few mins.
Once this has been done, and the heater goes though a heating cycle, then the unit should be back to full capacity.
The valve looks like this
If it dosent have one of these valves, then the above directions wont help anything
Ben
