I have a faulty immersion heater in a new apartment. The 'top up /
sink' option heats water for an hour or two but when I use the 'bath'
option for several hours over night there is no hot water in the
mornings. Would you think this points to a thermostat or element
Assuming it is an element problem, are these expensive? I have little
plumbing experience, would it be best to get a plumber to replace
It sounds as though your system switches between two thermostats, one
at high level so just the upper level of the tank gets heated, and one
at lower level doing the whole tank. If this is the case then I would
suspect that the lower thermostat is u/s. However you may have two
immersion heaters, one high & one low each with a thermostat pushed
down the centre. In this later case it could be either the lower
heater or the lower thermostat.
It is dead easy to replace the thermostats if you are electrically
competent - they just slide into a hole, however the immersion heaters
themselves can be a b***r to get unscrewed and you will have to drain
the system down. While the tank is still full of water (and hence has
a significant mass) try to slightly loosen the immersion heater with
the special big spanner and a thump from a hammer. If you try this on
an empty tank the probability is that the tank will bend all over the
The elements are relatively cheap and it is well worth getting a good
quality one intended for a hard water area.
Is the heater more likely to have two thermostats or two elements? I
am certain the problem is only with one 'thing' would you have any
tips on how I could check if it is the thermostat or the element. If
there is only one element then I know it is the thermostat but if
there is two elements and two thermostats is there a way I can know
what is faulty?
Thanks for your help,
To test the thermomstat you need to electrically isolate it, then
check it's electrical continuity when cold and it's lack of continuity
when hot (pan of water on the stove).
I suspect that if you need to ask these questions then it is perhaps
time to get someone else involved.
You are most likely correct and I probably will, I am just running
Since the 'boost / sink' option works would it be safe to say it is
probably an element problem or could it be the thermostat? If you have
no way of knowing without further tests I would understand.
It depends on what type of controller you have.
If you have an E7 controller for the immersion heater this will have its
own timeclock and both heaters will be run from the same circuit. (The
controller will prevent both running at once.)
If you *don't* have an E7 controller then the top heater will be wired
to your ordinary consumer unit and the bottom heater will be wired to
your off-peak/storage heater consumer unit.
Do you have storage heaters and do they work correctly? If they don't,
this points to a failure of the E7 timeclock which needs to be referred
to your electricity provider.
* check MCB of heater circuit(s) (peak and off-peak)
* check power to immersion heater terminals
* check immersion heater thermostat setting
* check overheat trip on immersion heater and reset if necessary
I've only tested one storage heater. It seems to charge at night, the
light goes on as one would expect. It won't release heat during the
day though. It is set the same as a heater I know works elsewhere but
releases no heat. Do you think these problems could be related?
if not then the element or thermostat in the heater has gone
The light coming on only shows that there is power to the appliance
It is unlikely that this is related to the other problem as you have another
storage heater that works. this shows that the E7 supply is functioning at
least to the E7 consumer unit
As others have said the questions you have needed to ask suggest that you
should get some one in
I have a storage heater in a different building that works. The one in
this apartment doesn't seem to. Power goes into it but it is not hot
in the mornings, this is quite similar to what is happening with the
immersion which is why I wonder if they are related. Both get power
when they are supposed to but neither are hot when they should be.
I am fully prepared to get someone in but I would like a good idea of
what I am talking about first. Since both the storage heater and the
immersion are getting power but not heating, could this be related to
the E7? I only moved into this apartment on Friday so have only had a
few days to look at this. I have never had a problem with water
heater / storage heaters before. It is only since Owain mentioned the
two of them I wonder could the issue be related.
If it is the E7 would both still get power but not actually heat?
Thanks for your help,
The indicator lights come on as they are supposed too, that is all I
have checked. Neither are heating though. Since the indicator lights
both come on I assume they are getting power yet neither heat up.
On 21 Mar 2007 04:13:58 -0700 someone who may be
email@example.com wrote this:-
You need to tell us whether your hot water cylinder has one
immersion heater or two. The way to do that is to look at it and see
if there is one cable or two going to it.
If there are two immersion heaters then the first place to look is
the lower immersion heater and it thermostat.
If there is one immersion heater then it is likely that the problem
is with the switch.
You also need to tell us what sort of tariff you are on. If it has
an off-peak element, usually called Economy 7 down south, then it
may be that there is a problem with the off-peak supply.
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
Interested to hear response, my partner's son has just moved into a new
build flat and has the same problem. I didn't have test equipment first
visit but will probably go back and have another look. Whereabouts
geographically are you (in case it's the same builder!)
(anti-spam is as easy as 1-2-3 - not)
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