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Economy 7 heating. water heated via a storage tank in loft. heated water is not hot enough recently. solution please?

wiring very old. New heating element fitted in tank recently but does not help.

4 Answers from MyBuilder Electricians

Best Answer

You do not say whether the elements are timed or not.

Usually being E7, there will be two seperate elements, one for nightime and one for boost. This is not always the case though as E7 can still be utilised using a single element.

Firstly ensure that you have a cionstant 240v supply. If there is a timer fitted ensure that this is giving the correct output for the correct timed period. If the timer was faulty then the element may not be being supplied with electricity for a long enough period for the water to reach desired temperature.

In any event, within the element a thermstat is located. I would first check and replace this if necessary. There is no simple way of checking this thermostat, although you could remove it, and check its continuity whilst immersed in say a saucepan of water being heated over a stove.

This could give you an indication of whether the circuit is being broken to early. I.E. before the stored water has reached desired tempreature.

Assuming all is well and you have checked / replaced element and thermostat,
then maybe the cylinder itself is scaled up. Sometimes cylinders can be 20 % full of lime scale. This could also effect the water temperature as the element could be getting too hot being surrounded by scale.

Adrian Hagger


Answered 18th Mar 2011

It might seem like a very obvious thing to check but was the immersion thermostat replaced at the same time as the element? Either way, take a look and see if the thermostat has temperature control and adjust it to suit. Only do that after you have isolated the supply because you will be exposing live parts to gain access. It might be as simple as that (I've got my fingers crossed for you). Also, if there is a timer on the immersion and the power to it has been interrupted, it may be that this is not correctly set, i.e. switching the element on when the economy tarrif is not supplying power depending upon your wiring installation. If in doubt at all - ask someone to come and take a look for you. Hope this helps, Steve


Answered 18th Mar 2011

most economy 7 cylinders have two immersions, one run on economy seven and a boost facility taken off your regular electric. Check the cylinder stat, usually attatched around the cylinder with net curtain wire, make sure it's around 60 degrees. Also on some immersions there is a thermostat inside the casing, this may be faulty and need replacing (about £10 tops) these often have a red reset button and temperature dial, ensure this is also on 60 degrees. Warning when you take the cover off there is live electric inside. Failing that, you need to call a local plumber or electrician to test where the the electric is failing. good luck


Answered 18th Mar 2011

Storage tank type/model would be a starting point to check the normal parameters and the heating element fitted. Usually the tanks have a thermostat that can be adjusted, in your case higher, to rise the temperature inside the tank. Or could be the fact that latelly there are more consumers and the water inside the tank runs out. Economy 7 means that you have only a limited amount of time electricity feeding the heating element. A site visit to asses the problem would be usefull, otherwise could lob hyphotesis at the problem all day long.


Answered 19th Mar 2011

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