Good day

My geyser keeps on losing water through the pressure release valve. I changed the valve and installed a new one, but the water keeps on getting out. I've asked a plumbing friend of mine, but he also doesn't know what the reason is. Can somebody please help.

Thanks

I've asked a plumbing friend of mine, but he also doesn't know what the reason is.
That's strange. The reason would be too high pressure or too high temperature.

First thing to do would be to get a pressure gauge and see what your water pressure is. If water pressure and temperature are reasonable, the next question is, do you have a check valve on the incoming water line? If so, install an expansion tank on the incoming water line to absorb the pressure created when heating the water.

We only put on the geyser when we use it once a week to do washing. It looks like the geyser doesn't build up any pressure, the moment we turn on the water, the geyser looses its water through the pressure release valve. I've changed the pressure release valve, but even this doesn't help. The geyser is not on, but the water is streaming out of the pressure release valve.

The release pressure of the T&P (temperature and pressure) should be around 150 PSI. Surely your water pressure isn't that high.
It must be defective. Was any heating (soldering) done near the valve during installation that may have damaged the washers?