immersion heater problems!!! all 7 of'em!

[egginyourface]

Ive been called out to about 7 different jobs this week!! All to check why newly fitted immersion heaters were not working properly.

Its always the same thing. Plumber fittied new immersion heater and since then the water doesnt get fully hot or after the 1st bath the water wont heat up enough till the next day.

Every single one i go to i find that the plumber has turned thermostat up to the max trying to fix the problem causing cut out to kick in!

My job is as always to check the wiring is done correctly and no loose connections. I never touch the thermostat.:6:

What causes this luke warm problem??

Is it a mistake made by plumber, wrong sized immersion, wrong type etc??


Somebody please tell me as i would like to understand this

 

[GLENNSPARK]

may be that the imersion heater aint big enough.....could be loose connections n all....

 

[GLENNSPARK]

i mean how does this work?....does the plumber wire em up...then you come round to check it or what?...

 

[Guitarist]

Have you checked the voltage at the element?
Please describe your fault-finding routine to us

 

[egginyourface]

connections are fine on al of them. Thats what i check first. On one particular job the plumber told me the new one he fitted was bigger than the old one. They even changed the stat.

Do immersions have any other cut outs in addition ??

 

[egginyourface]

voltage was there, i even stuck my amp meter on supply cable and it was pulling nearly 12 amps so the immersion is running

 

[i=p/u]

isit hard water area isit a cheap copper one??

 

[egginyourface]

also plumber told me he'd fitted titanium immersion element

 

[telectrix]

sometimes the customer doesn't realise that doing the washing up etc. actually uses hot water. don't take many bowlfuls to use a tankful.

 

[Guitarist]

If you have 230v at the element and it is pulling 12 amps then it is working. As tel said, if you are using hot water then it will take ages to heat up and be lukewarm. You know all this tho I'm sure :yes:

 

[GLENNSPARK]

sometimes the customer doesn't realise that doing the washing up etc. actually uses hot water. don't take many bowlfuls to use a tankful.

depends if she's any good at washing up.....like if it aint done right then you have to get her to do it again.......thus using more hot water.....

 

[oldtimer]

All immersions that I work with are 18 ohms between the DB and the element plus it pulls 12.6 amps and nothing here changes. I always measure from the DB to the element because this proves that the circuit is healthy the stat is on the high limit stat is ok the 20 amp switch is ok.

So my question is what controls these immersions is it a 20 DP switch in the kitchen is it on Off Peak is there a boost timer fitted somewhere ?

It should take about 1.5-2 hours to get up to temperature plus if you put an amp probe on you can turn the stat down until the current drops off. Also have you asked the plumber if he is changing the element and the stat at the same time yes I know that a stat comes fitted with a new element but you still need to ask . As for faults found I found 30% was the element 60% was the control stat hence why i carry 2 with me and 10% is the boost or eco 7 controller.

I had a guy once who said I have tested everything 18 ohms at the element 12 amps drawn and when I asked did you check the connection in the fuseboard I got why would I do that wel the answer is if you have a slack connection you will only emphasise it under high load conditions and the things that can do that is Cooker, Shower, Immersion, Storage heater

 

[GLENNSPARK]

All immersions that I work with are 18 ohms between the DB and the element plus it pulls 12.6 amps and nothing here changes. I always measure from the DB to the element because this proves that the circuit is healthy the stat is on the high limit stat is ok the 20 amp switch is ok.

So my question is what controls these immersions is it a 20 DP switch in the kitchen is it on Off Peak is there a boost timer fitted somewhere ?

It should take about 1.5-2 hours to get up to temperature plus if you put an amp probe on you can turn the stat down until the current drops off. Also have you asked the plumber if he is changing the element and the stat at the same time yes I know that a stat comes fitted with a new element but you still need to ask . As for faults found I found 30% was the element 60% was the control stat hence why i carry 2 with me and 10% is the boost or eco 7 controller.

I had a guy once who said I have tested everything 18 ohms at the element 12 amps drawn and when I asked did you check the connection in the fuseboard I got why would I do that wel the answer is if you have a slack connection you will only emphasise it under high load conditions and the things that can do that is Cooker, Shower, Immersion, Storage heater

this is it....any high resistance joints will prevent it from reaching full potential.....

 

[Guitarist]

If you are getting a full 230v at the element under load then it is normally a good sign.

 

[i=p/u]

makes sense to me when i apply ohms law

 

[Dcf]

I had this recently with various new style stats with the overheat cut out.turns out the tenants liked to keep the immersion on all the time so the top of the tank was probably hitting 90c enough to knock the thermostat cut out off.4 visits later and 4 different manufacturers stats later.i have found the cotherm ones about the most reliable.usually top entry heaters are the worst culprits I have found

 

[TaffyDuck]

Almost certainly these bloody thermal cut-outs they are fitting on a lot of new immersions now. There is often a little button on the top of the stat by the adjustable bit. You can bypass them, I do, that solves the problem

 

[i=p/u]

what about people leaving thm on and heading out by mistake???

 

[UKMeterman]

Taffy,
Would you be able to defend your bypassing of the cutout to this family? BBC NEWS | England | Somerset | Scald death family meet minister

 

[GLENNSPARK]

Almost certainly these bloody thermal cut-outs they are fitting on a lot of new immersions now. There is often a little button on the top of the stat by the adjustable bit. You can bypass them, I do, that solves the problem

well these were fitted after that baby got scolded...down birmingham i think.....but they are a pain them thermal cutouts....only thing though....if you intentionally bypass it....then that constitutes tampering....which will instantly null any warrenty....and if someone...or someones kid gets scalded as a result of your actions......youd be for the high jump mate.........