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DIY Forum >> Plumbing Questions >> No hot water from new immersion - help please!! https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1299362377 Message started by mike52 on Mar 5th, 2011, 9:59pm |
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Title: No hot water from new immersion - help please!! Post by mike52 on Mar 5th, 2011, 9:59pm I have a hot water system that consists of an immersion heater element into the top of a hot water tank for the hot water in my house (I have no boiler or central heating). 5 days ago it stopped working so I called a plumber. The plumber has now replaced the hot water tank as the old one was leaking, and fitted the new tank with a brand new immersion element (27") and thermostatic control. Unfortunately, I have had to have the plumber back 7 times over the past 4 days since fitting this tank/immersion as I still do not have hot water. After leaving the water to heat up in the tank for over 1 hour+ I then check it, and when you put your hand under the tap it is red-hot, but if I try to fill the bath after a minute or so it goes Luke-warm then cold (giving me only about 2 inches of hot water..). The plumber has replaced the thermostat (twice) and then today he replaced the full immersion element (27") with a new one - but yet it's still the same! We have tried turning the temperature up on the small screw controlled dial on top of the thermostat on the immersion element but if it's turned up too far the small reset button pops out to disable it - if its set even just slightly under that point then the water doesn't get hot enough...? Both myself and the plumber are scratching our heads as we cannot understand what is happening. I have even paid extra to get an electrician in and he has checked all of the wiring from the fuse box to the immersion and also checked the voltage directly to the unit and says all is fine - so I am desperate for someone to try to offer any advice as to what is wrong here.. I had also heard from a family member that he had a similar issue some years ago where the thermostat that was put in his tank was causing the same problem (not enough hot water) and he says the plumber changed it as he said he had put the wrong one in (he said he should have put a thermostat for 'hard' water rather than then one had put in - for 'soft' water).. Is this true and you have to have a thermostat for either 'hard' or 'soft' water? I really would appreciate any help and advice on this as it's driving us all crazy! :-? Mike |
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Title: Re: No hot water from new immersion - help please!! Post by CWatters on Mar 6th, 2011, 12:36am I'm not a plumber (but as a glider pilot I know a bit about thermal/rising warm air). I've heard that top mounted elements don't work as well as side mounted... I don't understand how a top element with built in stat can heat all the tank... What stops a thin later of very hot water forming at the top, satisfying the stat, and turning the element off while the bottom is still cold? If the element (and it's stat) is further down the tank convection currents should take the heat away to the top of the tank. The layer of hot at the top should get deeper and deeper into it reaches down to the stat. Is there a port on the tank lower down where an element can be fitted? |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 1:00am CWatters wrote on Mar 6th, 2011, 12:36am:
Hi - thanks for your reply. The element that has been fitted is 27" deep - so it should be ample for heating the tank - and as you say, allowing the convecting currents to heat lower down - that's what is confusing me/us.. It's as though only the top 3rd of the tank is being heated - and especially after the element was swapped for a new one - so if the first was faulty, this one should be OK, yet the same thing is happening. To answer your question about putting the element in lower down the tank - no, there is only the opening on top of the tank to put a vertical element/thermostat into. Regards Mike |
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Title: Re: No hot water from new immersion - help please!! Post by thescruff on Mar 6th, 2011, 3:47am how long is the immersion heater on for. What is the brand. Stat should be set at or abouts 60c. Yes you can get special immersion heaters for hard water, but unlikely to be the problem if it's only been installed a short time. |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 6:53am thescruff wrote on Mar 6th, 2011, 3:47am:
Hi Over the past 4 days we have left the heater constantly on for hours on end - checking the water temperature usually after 2-3 hours on average (testing by running a bath - but only manage to get about 2 inches of hot water each time before it runs cold). Cannot tell what the brand is as there is no markings on the element or thermostat. The plumber originally set the temp at 60 degrees, but it wasn't producing any more hot water than a sink full - so we have been adjusting the temperature ever upwards to see if we can get more hot water out - but as mentioned, what happens when you do is the reset button trips out.. I would have thought that logically even if you were going to use an element for 'hard water' it wouldn't matter initially (although I'm not a plumber - hence my checking to see if anyone knows whether there was a need for it or not). Regards Mike |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 7:11am I would get a sparks to look at that bud. If there is a fault on the supply to it there may not be enough electricity getting through to properly heat the element. |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 7:18am wrote on Mar 6th, 2011, 7:11am:
Morning Wayne - thanks for your reply Already did that - got a sparky to come and check the supply from the fuse box up through to the immersion - checking the voltage etc to ensure it was getting the correct supply and there was no breaks in the current or loose connections. He also checked the wiring on the immersion/thermostat to ensure it was wired correctly and that the current was ok to the connections on the thermostat.. So totally confused so far.. Regards Mike |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 7:23am Just to clarify your plumber replaced the copper cylinder as well or the Cold Tank feeding the cylinder? |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 7:39am Mike can you post a photograph of your Tank/Cylinder? Its easier if we can be sure exactly what is there bud. |
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Title: Re: No hot water from new immersion - help please!! Post by CWatters on Mar 6th, 2011, 9:04am If the stat in a top mounted element is right at the top of the tank I reckon could still be the effect I described (eg layer of hot forming at the top that turns off the stat). Simple test... Put the immersion on and see how long it actually continues to draw power before it's built in stat switches it off. |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 9:19am The only other time Ive gone to one like this they had too short a stat in a 27" imersion heater. |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 1:41pm wrote on Mar 6th, 2011, 7:23am:
Hi Wayne The plumber didn't replace the plastic header tank in the loft - he just replaced the large copper cylinder in the airing cupboard in the bedroom along with the immersion element (twice) and thermostat (twice). Best regards Mike |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 1:45pm wrote on Mar 6th, 2011, 7:39am:
Will take a couple of photos shortly (just got up as i'm on 12 hour nights at moment.. :'() |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 1:47pm Still sounds like a stat problem though. The only time ive been called to same fault, the thermostat was too short for the Imersion heater therefore was sensing the heat near the top of the cylinder. Unless you have another coincidental fault elsewhere e.g cold feeding into hot very unlikely then I would still point at the stat. But again photographs of cylinder and pipework would be helpful |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 1:48pm CWatters wrote on Mar 6th, 2011, 9:04am:
I will see what I can do to see how long it takes - will let you know |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 1:52pm wrote on Mar 6th, 2011, 9:19am:
Hi Wayne How long should the thermostat be for a 27" element? - I only know the element is 27" because the plumber mentioned it - and I am just wondering so I can ask him what he put in? I am not a plumber so am reluctant to start messing about with this myself, but if I know what he should be putting in I can ask him to see if that's the cause. thanks Mike |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 2:42pm wrote on Mar 6th, 2011, 7:39am:
Ok - hope these photos help? [gallery]mike52/1299422413.jpg[/gallery][gallery]mike52/1299422439.jpg[/gallery][gallery]mike52/1299422461.jpg[/gallery] |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 2:54pm The Stat on a 27" Immersion Heater is 18" it usualy fits the 30" and 36" as well. It may also be worth looking up the manufacturer of the cylinder to see what they recomend be fitted. |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 3:07pm wrote on Mar 6th, 2011, 2:54pm:
I will try to check with the plumber to see what he put in and also check with the mnufacturer - won't be until tomorrow though as it's Sunday. Can you see anything obvious from the photo's I posted? Thanks Mike |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 3:13pm To me it looks like either the stat in that Heater is too short or the manufacturer may specify a longer Heater and stat. But would ask them first. It may be as i say that they want you to fit a longer one? But would deffo get that stat pulled out of there and if its a 7" stat bingo swap that first. |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 3:15pm wrote on Mar 6th, 2011, 3:13pm:
Thanks Wayne - appreciate your help on this |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 3:22pm No worries the plumber will have bought it in good faith but balls ups on parts and bits are more common than you think and even though brand new it may yet be the new immersion heater, and also put the question to the manufacturer of the cylinder what they recomend as ideal for your situation and use. But get someone to pull that stat out and make sure deffo its not a 7" bud. |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 3:56pm wrote on Mar 6th, 2011, 3:22pm:
Will do :) |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 4:12pm wrote on Mar 6th, 2011, 3:22pm:
Just found the end of the box that housed the new immersion and thermostat the plumber put into the tank - he showed it to me to confirm he had put in a 27" element and an 18" thermostat - so I can definetely confirm it's an 18" thermostat and he has swopped it out twice - and the same for the immersion element.. I can understand that parts can get mixed up - but you would have thought that both he (the plumber) and the supplier would both know what particular type of immersion element and thermostat would be right for that tank.. - or am I being naive? ;) |
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Title: Re: No hot water from new immersion - help please!! Post by mike52 on Mar 6th, 2011, 5:09pm wrote on Mar 6th, 2011, 3:22pm:
Hi again Wayne Think we have sussed the problem out.. I have just had a friend around who is an electrician - he checked the power into and out of the thermostat again - and guess what.. it's only intermittently working, and then whilst doing it it started arcing inside - so it's definetely a faulty thermostat.. He thinks the suppliers have had a faulty batch - hence the plumber changing it and it still not working properly. I will get another thermostat in the morning and hopefully resolve the problem. Well, at least I know what it is now! Thanks for your help - it's been very much appreciated. ;D Mike |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 6th, 2011, 7:53pm Bloody knew it LOL Glad your sorted bud :) |
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Title: Re: No hot water from new immersion - help please!! Post by ronb on Mar 7th, 2011, 8:51pm Hi all this is my idea as water heats up it causes stratification ( water is hotter at top and temp drops as you get lower down the tank ) because the thermostat is built into the imersion heater element at the top of the tank it will cut out when the water at the top of the tank reaches 60.c whilst the water 1/3 of way down tank may be only 20.c is it posible to bypass emersion heater thermostat and fit a cylinder stat at 1/3 up from bottom ??? |
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Title: Re: No hot water from new immersion - help please!! Post by thescruff on Mar 8th, 2011, 3:59am No. Buy a Redring immersion heater and stat and try that. |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 8th, 2011, 6:10am Bit late lads it was sorted the other day it was a faulty stat. :) |
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Title: Re: No hot water from new immersion - help please!! Post by Wayne B on Mar 8th, 2011, 6:30am Start simple Ron lol always check basic stuff first before going in there heavy handed bud. A new stat is only about £6.00 and in this case the guy should get one free from the merchants who supplied the duff one. Just because something is brand new dont think it cant be faulty is the lesson in this case. :) |
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Title: Re: No hot water from new immersion - help please!! Post by Lectrician on Mar 19th, 2011, 7:53am Would be good if the OP would post back to confirm things now work.... |
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