electric water heater

zxcvbnm12

I have a problem with a water heater in a milking parlour.the safety valve at the bottom is leaking a lot of water.i cant really see the cap of the valve because its in an awkward place but i think it says 6.8 bar?does this sound right?the make and model of the heater is an "inventum pony direct"

They tend to be a 8 bar blow off, water heaters in milking parlours normally run to higher temperatures than domestic heaters, higher temperatures mean higher pressures.
A blow off releasing water tends to indicate a excessive pressure problem more than a defect with the valve, the normal reason for a blow going is incoming pressure over the 3.5 bar recommended, not enough expansion for the heated water on the cold water side or over heating of the heater. I have yet to come across a leaking blow off leaking because of a defective valve but you can't rule it out, Gary.

zxcvbnm12

does that mean so that if i change the blow off valve that the same thing will happen again.is this valve for excessive pressure or excessive heat

Normally if the blow off is leaking then it's the first sign that something is a miss with the installation and not a defect with the valve, you could try a new valve as this is a easy option.

You could try leaving the heater go cold, if the heater still leaks then the incoming water is to high or the valve is defective.

If you find the valve only leaks when hot than try turning down the stat to see if that has any impact(checking the out going temperature has dropped),if you have fitted a new valve and turning down the stat has not helped then think about fitting a expansion vessel on the cold water inlet or fit a pressure reducing valve if your incoming mains is over 3.5 bar.

zxcvbnm12

ok ill chance the valve first anyway.cheers for the advice