Immersion not heating up ??

ifconfig

The immersion for our hot water cylinder isn't heating up and doesn't seem to be drawing current.
A few months ago we had the element replaced (due to calcification and burn out).
In that case the element shorted and the circuit breaker for RCD tripped, etc.
This time there is no shorting, the power is being supplied but the water isn't heating.

I'm suspecting possibly it might be the thermostat being faulty and the immersion never being allowed to heat the water because of the faulty thermostat.
Are there other likely explanations ?

Coincidentally, the UFH/Ground source heat pump hasn't been coming on in the past 24hours and I have a guy coming to check that.
That is the usual way of heating the cylinder but I do often back that up with a boost from the immersion (especially if needing some hotter water later in the day).

Any ideas ??

—ifc

meercat

There is a high limit overheat trip on your immersion
This may have activated
Try and reset it
Can't link it at the minute but it has been discussed before,if you do a search here it should come up

dingding

ifconfig wrote: »

The immersion for our hot water cylinder isn't heating up and doesn't seem to be drawing current.
A few months ago we had the element replaced (due to calcification and burn out).
In that case the element shorted and the circuit breaker for RCD tripped, etc.
This time there is no shorting, the power is being supplied but the water isn't heating.

I'm suspecting possibly it might be the thermostat being faulty and the immersion never being allowed to heat the water because of the faulty thermostat.
Are there other likely explanations ?

Coincidentally, the UFH/Ground source heat pump hasn't been coming on in the past 24hours and I have a guy coming to check that.
That is the usual way of heating the cylinder but I do often back that up with a boost from the immersion (especially if needing some hotter water later in the day).

Any ideas ??

—ifc

Could be

High limit cut out on thermostat. Can be reset. (thanks meerkat)
Burnt out switch / time switch
Burnt out / faulty thermostat
Loose connection
Faulty cable
Faulty element


As you have replaced the element recently I would investigate in the order above.

dingding

meercat wrote: »

There is a high limit overheat trip on your immersion
This may have activated
Try and reset it
Can't link it at the minute but it has been discussed before,if you do a search here it should come up

I forgot about this. Add it to the top of my list.

ifconfig

Many thanks for all the replies.
High heat limit trip does sound plausible.

However, I think this is a false alarm.
The cylinder is now heating up fine.
I switched the hot water circuit breaker on and off at the fuseboard and , no idea if that helped but the cylinder is definitely heating the water now.

Another possibility is the fact that the heat pump programme to dump water into the cylinder probably filled the 300 litre vessel with cold water early this morning (since the heat pump is out of action and I still had that on a time programme). Perhaps all that was wrong was it took ages for a cold 300L cylinder to heat up.

Now, next on to the GSHP.
Last time it went on the blink it was a faulty soft-start module (blew as a result of an electricity surge. ..however, now I have a surge protector in the fuse board for that.. so not really sure what is going on there.. but that's more a plumbing/electrics issue than a straightforward electrical one).

—ifc

Wishful Thinking

Hi guys I wonder could anybody give me advice

The immersion tank couldn't heat up enough water to fill a full bath. I got a plumber to change the element but he wouldn't wire it so I got an electrician to wire it.

Once wired up it only heated up at the top of tank. They changed element again but still barely heated up. It seemed to be heating up well for a half hour but I came back an hour later & it hadn't heated up any more infact it felt like it cut out

Both plumber & electrician were stumped. Plumber said about sticking thermometer up to full blast & that might work...

...however last night I put on a fire. The fire is connected to tank. It was on for a good few hours & I noticed water hot so checked tank & it was blazing hot the whole way to bottom. So does this mean it's def an electrical problem with the wiring?

paddymick

Wishful Thinking wrote: »

Hi guys I wonder could anybody give me advice

The immersion tank couldn't heat up enough water to fill a full bath. I got a plumber to change the element but he wouldn't wire it so I got an electrician to wire it.

Once wired up it only heated up at the top of tank. They changed element again but still barely heated up. It seemed to be heating up well for a half hour but I came back an hour later & it hadn't heated up any more infact it felt like it cut out

Both plumber & electrician were stumped. Plumber said about sticking thermometer up to full blast & that might work...

...however last night I put on a fire. The fire is connected to tank. It was on for a good few hours & I noticed water hot so checked tank & it was blazing hot the whole way to bottom. So does this mean it's def an electrical problem with the wiring?

Im presuming you have the switch set to bath when it only heats half the tank.
Try it on sink for a few hours and see if it heats the whole tank.

Alot a people will just change the immersion swaping the wires like for like without checking which element is which.

The bath is usually the brown wire but I have found that sometimes they come prewired as the black so as a rule I would always check which element is which before i connect it.

If you turn it on and now nothing is happening then the high limit stat might have tripped(if you have one!)because you turned the stat up to max,
If so this will have to be reset and the stat temp will need to be turned back down to between 60 and 65 degrees.

meercat

i also think that its wired wrong

blue - neutral
black - sink
brown - bath

open your immersion switch and check how it is connected

post pics if possible

remember to turn power off

Bruthal

Bath and sink likely mixed up alright.


Anyone ever seen the blue as one of the elements? I seen it years ago.

Important not to have the neutral wrong anyway, or else the stat can be bypassed.

Unlikely here, but worth noting.

M cebee

no
but as paddymick said you have to confirm sink and bath
They're not always wired brown/bath and black/sink

meercat

robbie7730 wrote: »

Bath and sink likely mixed up alright.


Anyone ever seen the blue as one of the elements? I seen it years ago.

Important not to have the neutral wrong anyway, or else the stat can be bypassed.

Unlikely here, but worth noting.

it used to be blue sink/black bath but that was changed to ensure color harmonisation
that may be the problem here if he connected like with like

M cebee

years back i remember the blue as bath or sink alright

paddymick

meercat wrote: »

i also think that its wired wrong

blue - neutral
black - sink
brown - bath

open your immersion switch and check how it is connected

post pics if possible

remember to turn power off

I have also come across a lot of immersions that come prewired with a bit of flex being wired the wrong way around
so I would usually check the connections on the elements first as its handier than messing around with the switch and 9 times out of 10 this is where the problem is.
Because most people will just take it that the brown is bath and sink is black and connect them into the switch in their correct places without realising they are wrong at the element.

On a side note:If both your electrician and plumber couldnt figure out something as simple as an immersion problem i`d be asking questions maybe not so much the plumber but this is 2nd year apprentice stuff for an electrician.

meercat

called to immersion that wasnt heating water fully
everything worked as should but replaced the thermostat as a precaution
had to call the following week as still not functioning correctly
replaced the immersion this time
2 days later another call to say still not enough hot water
called back to check
hopped into the attic to hear the tank topping up
it turned out that there was a leak in the hot water pipe under the floor

op,check the tank in the attic to ensure its not topping up the cylinder

M cebee

ya ive seen that before alright

M cebee

you would expect a plumber to be aware of it but it's one for a sparkie to keep in mind alright

ngidragon

Hi, I dont have hot water in hot taps. Oil heater works fine. But no hot water in heating cylinder. Anybody can help?

Thanks

MIKEKC

New element fitted Whether switch is at sink or bath only top of tank heats. Changed wires around, still the same

meercat

MIKEKC wrote: »

New element fitted Whether switch is at sink or bath only top of tank heats. Changed wires around, still the same

Is probably not wired correctly.the wiring colors have been changed so don’t connect it to previous colors

The new connection should be

Black -sink
Brown-bath
Blue-neutral

MIKEKC

meercat wrote: »

Is probably not wired correctly.the wiring colors have been changed so don’t connect it to previous colors

The new connection should be

Black -sink
Brown-bath
Blue-neutral

Thanks, I wired it that way, no luck.If the bath and sink were wired the wrong way it should still heat just switch wrong way around?. The water is extra hot, I checked stat and it's just above 60

meercat

MIKEKC wrote: »

Thanks, I wired it that way, no luck.If the bath and sink were wired the wrong way it should still heat just switch wrong way around?. The water is extra hot, I checked stat and it's just above 60

If you have old style meter. Get some one to switch it on and look at how fast the dial spins
Switch between sink and bath to see if there’s any difference

MIKEKC

meercat wrote: »

If you have old style meter. Get some one to switch it on and look at how fast the dial spins
Switch between sink and bath to see if there’s any difference

Problem solved. Element is 2 feet long it's heating as far as this.Tank is 4 feet. If left on for a number of hours the heat goes down a bit further. Old element was also 2 feet and provided enough hot water for a bath. Just never checked how far down it heated before.