[Plumbing] Hot water from cold taps

[Milano]

Moved house. When I switch off the property's water supply at the meter, I get full-on hot water coming out the cold taps, including outdoor garden taps. What is the meaning of this?

 

[Grouter]

Same. It means we are missing some sort of valve somewhere near the geyser which is meant to prevent this kind of thing. Shortcuts taken by the plumber / installer. I live with it. Geyser is 30 years old - I'm not messing with it till I have to.

 

[catman37]

Same. It means we are missing some sort of valve somewhere near the geyser which is meant to prevent this kind of thing. Shortcuts taken by the plumber / installer. I live with it. Geyser is 30 years old - I'm not messing with it till I have to.

Are you talking about the Vacuum Breaker's ?

 

[Grouter]

Are you talking about the Vacuum Breaker's ?

Dunno. I'm not a plumber. Although I think there is a vacuum breaker up there somewhere - can't recall.

 

[Sinbad]

Are you talking about the Vacuum Breaker's ?

Could be missing a vacuum breaker on the supply side of the geyser I guess.
Basically, water is running backward out of the geyser into the cold supply line, and from there out the taps.

http://www.housecheck.co.za/hot-water-geysers/

 

[Grouter]

Could be missing a vacuum breaker on the supply side of the geyser I guess.
Basically, water is running backward out of the geyser into the cold supply line, and from there out the taps.

http://www.housecheck.co.za/hot-water-geysers/

I think you're right. I seem to recall I only have a vacuum breaker on the geyser outlet, hence my same problem as op.

 

[Sinbad]

I think you're right. I seem to recall I only have a vacuum breaker on the geyser outlet, hence my same problem as op.

Be aware then that your cold taps will empty your geyser, and switch off your element if you have a water outage, to prevent it burning out...

 

[Grouter]

Be aware then that your cold taps will empty your geyser, and switch off your element if you have a water outage, to prevent it burning out...

My temp solution has been to put a non-return valve in at the meter on the property boundary. If we ever lose municipal pressure, the borehole takes over automatically.

 

[creeper]

Are you talking about the Vacuum Breaker's ?

I had the same problem. It was a stick vacuum breaker. The plumber just reset it.

 

[Milano]

Be aware then that your cold taps will empty your geyser, and switch off your element if you have a water outage, to prevent it burning out...

Weird part is that I would estimate maximum 30 to 50 litres of hot water loss before the water stopped completely. As though it does not empty the entire geyser, but definately around 25% of the geyser water was lost. Are the vacuum breakers indicated by the number 9 on the diagram you linked to? Will get it checked out by a plumber. Appreciate it!