# Forum Home Renovation Plumbing  Zip Hydrotap Problem

## mr nick

I have a Zip Hydrotap that has been working fine for ages but has this week developed a fault. Woke one morning to find that the power had gone off in the kitchen and when resetting the RCD it would stay on for about 3 seconds and then trip again. After a quick process of elimination by unplugging certain items I found the Hydrotap was the culprit. About a year ago it developed a very slow leak when one of the internal fittings started to fail and when enough water was in the base of the unit it would trip the power but this was easily fixed by replacing the faulty joint. I assumed that it would be a similar problem this time around but on opening the unit it is completely dry inside so I'm now left wondering. 
When I power the unit up, it goes through the start-up procedure but once it gets to the 'normal operating' stage it then trips the power. Has anybody out there had any similar experiences with these units that could offer any guidance? The unit is a good few years old now and well out of its warranty period so I'm guessing a Zip repair may be pretty pricey  :Eek: .

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## plum

You'll struggle to find someone outside of Zip to fault find.

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## Random Username

My first guess, based on the quick trip and lack of obvious causes, would be that the element has a big enough leak to earth to pop the RCD...either that, or there's a pretty good short somewhere inside to cause enough of a current draw to pop it in three seconds.

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## mr nick

My first thought was the element. If I disconnect it, the unit powers up and the chiller works perfectly so I know that it's at least a problem on the boiling side (typical that it's the bit we use most that's got the fault). There appears to be no leakage to earth from the element while the element itself has a resistance of approx 39ohms - need to do the maths on that aspect to see if that is a legitimate value or not. I can't see any other obvious visible problems like burnt wires or discoloured components on the PCB. I need to do a few more tests of disconnecting sections of wiring to see if it is possibly something in the element control wiring rather than just the element itself but it's a bit tricky at the moment with two kids doing homework on computers so I can't keep tripping the power every few minutes. Looks like I need to go and buy an emergency kettle - I'm dying for a cup of tea!

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## joynz

For the tea, heat up a pot of water on the stove.

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## Ozcar

39 ohms equates to around 1400 watts (depending on exactly what you take the mains voltage to be), which sounds reasonable to me. The insulation may only break down at a relatively high voltage, so measuring is with a normal multimeter may not give you the whole story. 
If all you disconnected was the element and the problem goes away I think you have close to proved where the fault is. I suppose it is possible that the control circuit might do some sort of test on the element, perhaps as part of a "zero crossing" detection circuit, and decide not to power up the element, which could mask a fault somewhere else. You could perhaps substitute an incandescent lamp for the element and see if it turns on, but you would have to be very very careful about doing that.

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## mr nick

If I disconnect the water level sensor the fault doesn't trigger but I guess that would be because the element doesn't get powered up as a safety measure. If I disconnect most other sensors, I just get fault messages and nothing starts up. I think I'll have a go with the lamp test and see what that throws up.

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## Marc

We have a Zip hot/cold water tap at work and it fails very second year. Zip guy comes in an replaces the whole tap, element tank whatever. Last time the bill was $2000 ...  :Frown:

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## Random Username

With a spare suicide lead, wire the element up by itself without the Zip controls, and give it the smoke test...that'll at least eliminate one more thing. (I'm assuming you don't have a megger to do a high voltage insulation test between the element and earth). 
The trouble with heating elements is that if the magnesium oxide insulator inside them gets damp, you get a tiny leak to earth, and once that gets high enough, it trips the RCD. 
After that, it could be some capacitive coupling somewhere on the circuit board...which is where it meets my 'spray it with metho to clean it off and let it dry out' methodology runs out of puff!  https://www.youtube.com/watch?v=TdeU6UCCfTY

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## mr nick

> We have a Zip hot/cold water tap at work and it fails very second year. Zip guy comes in an replaces the whole tap, element tank whatever. Last time the bill was $2000 ...

  Mine is about 8 years old and other than a failed o-ring in one of the pipe joints, this is the first problem I've had. Hoping it's an easy (and cheap) fix.

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## mr nick

I've been working out of town for the past few weeks so only just got around to tackling this. I used the suggested method of connecting a lamp in place of the element and sure enough the unit started up with no problems. I then  used the suicide lead connected to the element and that took out the RCD so that confirmed where the problem was. Did a bit of googling and found an element for $150 delivered which arrived yesterday. Nice easy job to replace it and now it's all back up and running.

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## Random Username

Yay!

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