Immersion - all seems good but still no heat

apeking

Hi guys.

Got a plumber to install two new element today in the hot tank. It is a dual immersion and the elements go in the side. One top and one bottom. They are connected to a timer so t bottom one comes on at night and the top is boost.

Now the problem is the top one is working perfect however the bottom one isn't. They are wired the exact same.

I have checked the voltage both before and after the stat and all Is good. I've checked the resistance across the element with the power off and its 18ohms. I've checked the continuity between element and switch and all is good there.

Anything else I can try? It isn't heating up at all. The plumber said he would fit them but if there was any electric problems I'd need to call an electrician

Squidwert

The stat mite need to be reset. Looking at the pic it could be the little blue button on the top of the stat

apeking

Squidwert wrote: »

The stat mite need to be reset.

Thanks

Tried that by pushing the button in and also if the stat was open I wouldn't be getting a reading of 230v after the stat

bucky08

try bypassing stat and leave on for 1hour and check if water is getting hot

Irish Steve

OK, There's 230v there, where is your neutral probe connected to get that voltage?

I would be looking for an open circuit neutral back as far as the point where the neutrals meet from both heaters.

There is also some switching somewhere, and some of the switches that are used in dual immersions are put into the neutral line. maybe a contact has burnt out in one of the switches?

Make sure that the neutral has continuity through the time switch, at the extreme, there should be 18 Ohms on the line to neutral before the time switch at the incoming supply point. Be careful to make sure it's isolated if you are upstream of the timeswitch.

apeking

Thanks for your help. Left it to come on for 4 hours over night and now have hot water. Didn't change anything.....very strange

hufpc8w3adnk65

Just cuz theres 230v at an appliance doesn't mean it's drawing current thus still could be non operational

frankmul

apeking wrote: »

Thanks for your help. Left it to come on for 4 hours over night and now have hot water. Didn't change anything.....very strange

The lower element is heating the whole tank which will take longer to rise in temperature compared to the upper element which is only heating the top portion of the tank. Small volume of water which will heat quicker.

Did you leave it on long enough to see the effect of the lower Element been on

apeking

Left it on for an hour the first time and no heat at all. It was times to go for 4 hours over night and had hot water this morning.

Was thinking today that it could have been that only the bottom element comes on during the nite rate electricity but that couldn't be the case as there was power at the element

Bruthal

apeking wrote: »

Thanks

Tried that by pushing the button in and also if the stat was open I wouldn't be getting a reading of 230v after the stat

What points exactly did you measure between to get the 230v?

apeking

Bruthal wrote: »

What points exactly did you measure between to get the 230v?

After the stat(live) and neutral on element

Bruthal

apeking wrote: »

After the stat(live) and neutral on element

So on the white wire and element neutral end of element?

If you have 230v on them, then there is 230v to the element, but the stat could still be faulty, and not continuously powering the element, or the element itself, but the element would be expected to be ok, and you measured 18 ohms which is correct for a 3kw element.

But if I was to hazard a guess, id say some sort of connection problem to the element supply flex, causing it to work intermittently.

apeking

Bruthal wrote: »

So on the white wire and element neutral end of element?

If you have 230v on them, then there is 230v to the element, but the stat could still be faulty, and not continuously powering the element, or the element itself, but the element would be expected to be ok, and you measured 18 ohms which is correct for a 3kw element.

But if I was to hazard a guess, id say some sort of connection problem to the element supply flex, causing it to work intermittently.

Yep tested on white wire and blue end of element as per the pic.

Ill see how I get on over the next few days and let you know. Thanks for your help

Cushie Butterfield

apeking wrote: »

Was thinking today that it could have been that only the bottom element comes on during the nite rate electricity but that couldn't be the case as there was power at the element

This is the case. Only one element can be heating the tank at any given time. The boost switch will not trigger the top element to heat the water during the four hours that the bottom element is timed to heat (even if the bottom element is blown/malfunctioning), so you may be worrying unnecessarily.