Help! Water dripping through tundish of unvented cylinder.

15 Aug 2022
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United Kingdom
Hello, please forgive the stupid question, I'm a new homeowner so very noob. I've just discovered that water has been dripping through the tundish of our unvented hot water cylinder. A bit concerned that it may explode in the middle of the night. How can I "turn it off" safely while we wait for a plumber? So far all I have done is turning off the immersion heater (which is controlled by an economy 7 switch), but the water still continues dripping.

Many thanks!
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If the immersion is turned off then just turn the cold feed to the cylinder off and it will be fine until your plumber gets there
Many thanks for the quick replies guys.

@flameport It's called ThermaQ Evocyl 120 Slimline Direct Unvented Storage Cylinder.

@Razor900 Will there be a problem if I don't turn the cold feed off? I don't know where it is and without manufacturer instruction it's scary to touch the thing.

A few photos:


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Assuming the pipe is terminated properly it won't cause any problems it will just drip.

If you do want ti turn the feed off it's this valve. It will only turn one way 1/4 turn until the handle is horizontal

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Do that (leave it alone)! They're often piped up incorrectly. We can't see what that valve actually does.
A bit of a drip isn't an emergency so no need to panic or pay emergency rates.
Ask on the phone if the plumber is G3 registered. If not, try a different one.
G3 is the part of the regs which applies, you have to do a 1 day course for it, periodically renewed.
G3 should sort out, possibly expansion vessel problem, but still two levels of protection, the expansion valve which operates (opens) at 6.0bar and the temperature & pressure valve which opens at 7.0bar.

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