geyser problems - some advice needed please

[Justloadit]

The biggest problem with blocked pipes is usually gunk stuck in the the filters that are usually part of certain parts iin the plumbing line. Usually there is a strain filter before a pressure valve, non return valve, mixers, and also at the end of many taps. They usually have a screw type of end, which is part of an aerator. There is usually a wire mesh here and with time clogs up with stones and debris, and causes the type of flow no flow problems one encounters. Check these before stripping all the pipes.

[wynn]

Sounds to me like you are getting an airlock in the pipework from the geyser to the hot taps.

best way forward is to take the shower head off block the shower outlet off with one hand and a damp towel then open the cold water tap a little and slowly open the hot tap so that the cold water runs back up the hot water line and pushes the air back into the geyser.
Once the air is in the geyser the air relief/vaccuum breaker valve should do the rest.

The other thing that concerns me is the mention of galvanised pipe, it is notorius for scaling up and sometimes is so narrow and tortuous that a loose bit of dirt or scale the size of a match head can cause a blockage.

[SilverNodashi]

hi everyone. I just want to give some feedback. Since cleaning out all the pipes, the geyser didn't give anymore problems again. And it's been just over a month since my mom had the problems. So in this case it seems like the inlet was simply not supplying quick enough to keep the geyser pressurized enough to make it work properly - or something like that?