Immersion on for 3 hours but shower barely lukewarm

LazySamaritan

Hi,

Plumbing and heating are not my area at all.

Should the immersion by itself be enough to for a very hot shower? I switched it on about 11 this morning and had a shower about 2:45. The water was only lukewarm, if even that.

Before the shower the top of the tank felt quite warm. It was set set to "sink"and I was thinking I should have set it to "bath"but the water in the sink wasn't vey hot either.

How do I get the immersion to heat up more - and faster - without turning the gas?

Cheers

Conservatory

Put it on bath?

LazySamaritan

Conservatory wrote: »

Put it on bath?

Sorry I should added other details.

Since moving in last October I'd been heating the water with the boiler and turning the immersion on with it made it heat up faster and stay hotter longer, but the switch was always set to to "sink". Plus the other day the immersion was on on for less time than today but gave me hotter water for longer and the switch was on "sink".

And since the sink water doesn't get very hot either I was wondering could there be another problem.

I have the immersion on with "bath" now to test it.

Sleeper12

Sink will only heat the upper part of the cylinder. Leave it on 10 hours and it will still only heat the top of the cylinder. That should be enough for a quick shower but I'm betting over the 3 hours someone washed their hands in hot water and possibly washed dishes etc.

In the winter it was the gas boiler that gave you a full cylinder. Today if you had the switch on bath you would have had a full cylinder in 90 to 120 minutes

TomOnBoard

There's a thermostat on the immersion heater. Check it. It could be set too low for you.

The sink vs bath setting is about volume of water and the speed its heated. Either one won't heat hotter than the other.

If that's all good, then the shower itself could be the probkem. Again, a thermostat in the shower may be at fault. What make/model is the shower?

Bigserious1

Maybe one of the hot water taps was dripping slightly? Or you didn't run the shower for long enough.

Griffinx

I have a similar issue in that with the immersion on Bath, it doesn't heat a full tank. Would the thermostat be faulty (ie cutting out too soon) and is there a way to test this. Here's pics of the immersion with the top on and off. I think the thermostat is set to max?

Another point is that when the water is heating, you can hear it heating...not sure if that indicates anything.

Thanks

John.G

Griffinx wrote: »

I have a similar issue in that with the immersion on Bath, it doesn't heat a full tank. Would the thermostat be faulty (ie cutting out too soon) and is there a way to test this. Here's pics of the immersion with the top on and off. I think the thermostat is set to max?

Another point is that when the water is heating, you can hear it heating...not sure if that indicates anything.

Thanks

The thermostat seems to be set to minimum, try rotating it clockwise to say "10 oclock" and see how you get on, the max setting is possibly 80C and the minimum 40C.
Hearing the water heating is normal.

TomOnBoard

John.G wrote: »

The thermostat seems to be set to minimum, try rotating it clockwise to say "10 oclock" and see how you get on, the max setting is possibly 80C and the minimum 40C.
Hearing the water heating is normal.

Surely that thermostat is at 9 o clock now, and is at the top if its range, being pointed at the + end of that range?

evolving_doors

Could it be caked in limescale?

Griffinx

evolving_doors wrote: »

Could it be caked in limescale?

Its 12 years old and the water has limescale so possibly...any way to know? And how would this effect operation?

John.G

TomOnBoard wrote: »

Surely that thermostat is at 9 o clock now, and is at the top if its range, being pointed at the + end of that range?

Yes, it does appear that way, I mistook the + as being - , I suppose I,m used to seeing the setting knob to be turned clockwise to increase the setpoint temperature.

Griffinx

TomOnBoard wrote: »

Surely that thermostat is at 9 o clock now, and is at the top if its range, being pointed at the + end of that range?

Yes its pointing to + and the water is quite hot...its just that theres not enough of it....it doesnt seemt to heat the whole tank when on Bath

TomOnBoard

Griffinx wrote: »

It's 12 years old and the water has limescale so possibly...any way to know? And how would this effect operation?

If the element is caked in timescale this would certainly affect heat transfer from the element to the water as the timescale acts as an insulator. This can also increase your electricity usage.

The only way to know for sure is to drain the cylinder and remove the immersion. However, this may be a bad idea because if there is a bad timescale issue, that immersion may be seized in place. This can result in the threaded socket on top of the cylinder breaking away from the copper of the cylinder itself.. That would end up in needing a new cylinder.. :-(

Griffinx

TomOnBoard wrote: »

If the element is caked in timescale this would certainly affect heat transfer from the element to the water as the timescale acts as an insulator. This can also increase your electricity usage.

The only way to know for sure is to drain the cylinder and remove the immersion. However, this may be a bad idea because if there is a bad timescale issue, that immersion may be seized in place. This can result in the threaded socket on top of the cylinder breaking away from the copper of the cylinder itself.. That would end up in needing a new cylinder.. :-(

Think I might wait for it to stop working altogether before I look at that option

TomOnBoard

Griffinx wrote: »

Think I might wait for it to stop working altogether before I look at that option

It sounds like the thermostat is working.

It may also be worth getting an electrician to check the bath element to see if it is drawing current properly. If not, then element on the heater may be fubar, or the Bath switch may be fubar...

Griffinx

TomOnBoard wrote: »

It sounds like the thermostat is working.

It may also be worth getting an electrician to check the bath element to see if it is drawing current properly. If not, then element on the heater may be fubar, or the Bath switch may be fubar...

From the rating on the lid, it says Boost = 2kW and Bulk = 2.8kW, would this translate to a current of 8.3A for Sink and 11.6A for Bath?

Sleeper12

TomOnBoard wrote:

It may also be worth getting an electrician to check the bath element to see if it is drawing current properly. If not, then element on the heater may be fubar, or the Bath switch may be fubar...

Unless I've missed some posts OP only used Sink.

TomOnBoard

Sleeper12 wrote: »

Unless I've missed some posts OP only used Sink.

Nope! OP used both.

TomOnBoard

Griffinx wrote: »

From the rating on the lid, it says Boost = 2kW and Bulk = 2.8kW, would this translate to a current of 8.3A for Sink and 11.6A for Bath?

Beyond my knowledge I'm afraid. I reckon the sparks would measure the resistance of each of the elements first to check if they're working ok.

Wearb

Griffinx wrote: »

From the rating on the lid, it says Boost = 2kW and Bulk = 2.8kW, would this translate to a current of 8.3A for Sink and 11.6A for Bath?

Near enough. I think 230V would be nearer the norm here.

John.G

Griffinx wrote: »

From the rating on the lid, it says Boost = 2kW and Bulk = 2.8kW, would this translate to a current of 8.3A for Sink and 11.6A for Bath?

At a nominal 230V the 2 KW element should have a resistance of 26.5 omms & a current draw of 8.7 amps. The 2.8 KW element should be 18.9 ohms/12.2 amps.
If you have a "ESB" meter with a spinning disc it is quite easy to do a pretty accurate check on the element power. The meter will have the revs/kwh stamped on it, mine is 225 revs/kwh. ensure that all the usual heavy users ie fridge & fridge/freezers TVs etc are switched off and then check how many secs it takes for say 10 revolutions of the disc, say (with a 225 revs/kwh meter) and it took 80 secs the kwh are then (10*3600)/(225*80) = 2 Kwh. and so on.

Griffinx

John.G wrote: »

At a nominal 230V the 2 KW element should have a resistance of 26.5 omms & a current draw of 8.7 amps. The 2.8 KW element should be 18.9 ohms/12.2 amps.
If you have a "ESB" meter with a spinning disc it is quite easy to do a pretty accurate check on the element power. The meter will have the revs/kwh stamped on it, mine is 225 revs/kwh. ensure that all the usual heavy users ie fridge & fridge/freezers TVs etc are switched off and then check how many secs it takes for say 10 revolutions of the disc, say (with a 225 revs/kwh meter) and it took 80 secs the kwh are then (10*3600)/(225*80) = 2 Kwh. and so on.

Thanks, I just have a standard Amp/Volt meter. Would it be more usual to measure the resistance of the elements rather than the current when testing?

John.G

Griffinx wrote: »

Thanks, I just have a standard Amp/Volt meter. Would it be more usual to measure the resistance of the elements rather than the current when testing?

If you feel happy/competent to do so and after ensuring the power supply off to the immersion you could measure the resistance of both elements, I wouldn't be too happy measuring the current with a multimeter except for very small power users.

LazySamaritan

Thanks everyone.

Bath setting wasn't working either at the time so we called a plumber. Woking now but I wasn't in when he called around so don't know what the problem was.