Discussion in 'Electricians' Talk' started by Martin Greshoff, Oct 11, 2021.
Well the top element is used for a boost for your hot water as I am sure you will know and is obviously quicker to heat up less water which would normally be already warm, The bottom element has to heat up the full content of the water and usually from cold. You mentioned that the timer is set for 3 hours and is connected to the bottom element? If I am correct with this then it looks very much like if you are switching it on for only 3 hours through the night then the water will only be warm by the morning. Also what is the stat temperature set to?
In my old tank 3 hours was sufficient for heating the tank. The ‘hot’ water rarely runs cold so there is always some warm water left in the tank. The thermostat is set to 70
The stat is ok so now the thing to try is to leave the timer on for a longer period to see how long it takes to heat the full tank up on your new set up. I am pretty much convinced that this is your problem that the 3 hour period is not enough. I am not a plumber but I am a sparks and years ago when economy seven was in its prime, we did exact set ups to how yours is now, the bottom element was on throughout the night from say midnight to 6 am, once the water has reached the set temp the stat will stop the immersion from being on all of the time. the top element was for day time use once the water had been used up.
I will try setting the timer to 5 hours tonight to see if it makes a difference
I would certainly do this as to be honest, it sounds more likely to be your problem, you don't have to worry about a longer period to heat up from your old system, your old element may have been more efficient than the new one, the point is that if you try this and it works out well as it should, then you have solved the issue and ruled out another possibility if it doesnt make any difference. I also would not fret over using more electricity than it needs by increasing your timer as once the water has reached the stat temp, it will switch off automatically and stiop using the energy via the stat.
I will let you know tomorrow morning
I am convinced it will be better, but look forward to hearing as it will have ruled out another theory if it isnt better.
Why is there a timer for the bottom element?
Is it supplied from a dedicated off peak supply?
Why do the different elements make different sounds when heating up? THey are identical elements and I would have thought they should make the same sound when heating up
I am guessing here but I imagine that the element is at the top and less water to heat and not submerged with as much water above it, the bottom element has a lot of water above it acting like a sound barrier. The tank has an air gap at the top too so it isnt filled right up.
I would pretty much agree with that ^^^, but also include the water temperature. A kettle for example makes a different sound when heating to boiling.
You will probably find if the bottom heater gets close to the same temperature as the top one it will be a similar sound, not the same sound though due to the volume of water it is rattling.
3 hours plenty of time , unless,,,,,,, it’s 4000 litre cylinder
Yes agree Nigel but we dont know when his timer comes on and goes off through the night, if the tank heats up by say 1am, and they turn on a hot water tap at 7 or 8 am, the water may have lost a bit of heat to make it only warm by the time they come to use it. I had a customer who was heating his water up at 7pm and had lovely hot water then in the morning it was just warm as it had heated up and they had used it before they went to bed.
3 hours was enough time to heat the full tank before I replaced it. I will see what happens when I extend the time tonight
The tank is 1200mm x 450mm about 200l
After increasing the time the bottom element is on for the water temperature is possibly a fraction warmer but certainly not 70 degrees or has hot when using the top element
OK well rules out the time itt takes then, this has 3 areas of concern, the three items are faulty stat holding off the element from heating to the correct temp or even possibly wired incorrectly? A duff Element, even though both of these items have been replaced and appears to test ok doesnt mean it is actually ok. The timer is not actually putting the output at the times it should be, First thing is to rule out the timer now. take the butyl out of the timer and wire it direct to the switch and switch it on, see how long it takes now to heat up if it heats up at all. If it doesnt heat up that leaves just the stat and element. Bypass the stat and see if the element heats up, when testing this dont leave the tank on for too long,, you are testing the element to rule that out, you are just looking for the water heating up more than it currently is. Any of these tests will give you your results and diagnosis.
Slight difference on "wot he sed^^^" lol, swap the stats round, top one move to bottom and bottom move to top. If the fault moves it's the stat, if not its summat else
I have already replaced the stat with one I know works. Issue persists
I am sure the timer is ok as it was recently replaced and was working fine until I replaced the tank. I will try bypassing the timer. Thermostat has already been replaced with one I know works.
Thanks for your advice
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