Immersion heaters keep cutting out All aspects of plumbing questions and answers, help, tips and information

[alldaysmith]

I have a hot water tank in a flat that rent out. 10 months ago we installed brand new immersion heaters. Both of the immersion heaters in the tank have there own temperature dial setting and they both keep tripping out (there is a small trip button on each) regardless of the temperature they are set at. Does anyone have any ideas whay may be causing this and what i can do to stop it. My tennants are getting annoyed at having no hot water. Thanks :?

[rosebery]

The thermostat should be set to around 65 degrees (minimum 60 to avoid microbe growth). Any temperature above that runs the risk of the cylinder and imersion element furring-up. There is also the risk of scalding at higher temperatures.

The immersion heater trips out because there is a legal requirement for all immersion heaters to have a safety cutout built into them. I think this operates at iro 95 degrees, is factory set and is not user adjustable.

Is the insulation covering the top of the imersion heater. If so then this could be causing it to heat up and trigger the cut out.

I suggest you need to get a professional in to look at it.

Cheers

[stigdee]

I have exactly the same problem with a newly fitted immersion heater bought from Wickes ,it worked fine for about a month but now trips out regardless of the temperature setting.There is no insulation on the top of the heater and it is not over heating as the water stays cold until I reset the trip.

[matth]

I am currently having the same problem. Put new tank + immersion and manual (7 day) time switch in 12 months ago, from new it would cut out (trip the little immersion switch) every few days - annoying. Being idle I have lived with it but it's now ridiculous, tripping every day, at random. Temerature was set down to 50. No insulation covering heater (tank the foam pre-insulated type). Have re-wired it all and checked every connection yesterday, nothing loose etc. Have now just by-passed the timer to see if that has anything to do with it. If not, new thermostat?
Anything else possible? Odd that it has done it from brand new. Matt.

[gregch]

Did anyone find an answer to this problem? Our thermostat recently failed, leaving the water to boil, so I shut it off and called a plumber. Given that the heater had been in there for a few years now and was bound to peg out before long (very hard water area), I asked the guy to replace the immersion heater itself.

The new heater was installed on Monday, worked for a bit then tripped out. Reset on Tuesday, same problem. Called the plumber back and he replaced the thermostat on Wednesday believing that to be the fault. Same problem Wednesday night. We have an electronic timer (set to on all the time at least until this problem is sorted), and all the wiring, fuses, etc are fine. Current is getting to the heater no problem. The thermostat is set to about 63 deg.

It seems to me that the answer must be that the heater itself is faulty, that the 'pre-set' 95 deg cutout in the heater is operating in error... how likely is that?? I'm a bit hesitant to just replace the heater myself if it's not very likely because each time I undo the heater boss I'm scared of ripping the tank! That's why I got a professional in, although having charged me £90 he now seems completely stumped.

It's now 4 days later, no hot water and I'm starting to smell pretty bad!

[stuart_craigon2003]

rite, it seams to me that it is the same heater from wickes either that or the same make.get one that is not made by the same people or not from wickes and see how you get on!

[chris_on_tour2002]

might be an idea to contact the manufacturers in each case of the faulty part to see if they can shed any light.

[John MacLeod]

[quote]"stuart_craigon2003"]rite, it seams to me that it is the same heater from wickes either that or the same make.get one that is not made by the same people or not from wickes and see how you get on![/quote]It would be a help if we knew what the make and model were, rather than "it came from Wickes." I'm having a similar problem with a model IH525, the distributors' identity on the enclosed leaflet being Euro Plumbing Supplies.

[revchris]

Has anyone come up with a reason/solution to this problem? i.e. random cutting out of immersion heater theomostat when temperature is obviously within normal limits. I am on my second thermostat but this one trips out like the previous for no apparent reason. Any advice appreciated

Chris L

[plumbbob]

Although I have never come across this fault, I have seen some elements on a immersion heater that are bent either before or during installation to a degree they are nearly touching the thermostat housing.

It would seem possible the element itself might be heating the thermostat causing it to trip.

I do point out this is only an educated guess, but it may be well worth removing the whole assembly just to check that this is not happening.

[John MacLeod]

[quote="revchris"]Has anyone come up with a reason/solution to this problem? i.e. random cutting out of immersion heater theomostat when temperature is obviously within normal limits. I am on my second thermostat but this one trips out like the previous for no apparent reason. Any advice appreciated

Chris L[/quote]You've tried two stats -- but I suspect the reason is that the stats are of the "cheap and nasty" variety and the markings on them probably bear little or no relationship to reality.

Turn the stat down another five degrees. Pay no attention to the figures on the dial in terms of desired temperature but see if that cures the problem.

If it doesn't cure the problem, then turn down another five degrees and see if that does the job.

Continue the process until the cutout stops operating randomly.

Is your hot water still hot enough? If it is, you've solved the problem. If it isn't, get a better-quality thermostat.

[jim the plumb]

I would agree with John MacLeod.

I used to have a cylinder before fitting a combi boiler and once took a temperature reading of my hot water with the thermostat set at approx 55degC - to help prevent limescale build up.

The actual temperature was 78degC! To get a 55degC temperature I had to have the thermostat set to the minimum mark.

HTH jimbo

[william_morley]

I have just moved into a new flat and the Immersion heater and tank were installed in 2003, I just want to check that my immersion heater will cut off if I leave it on overnight when it reaches the desired temperature and im not sure if it has a temperature guide can anyone help?

[karlaa86]

hello there, i have a different problem with my immersion heater.
i have moved in to a new flat two weeks ago.It is all electric.
there is a water tank in the cupboard megaflo sadia heatrae dd125 with two switches on the wall. one of them is going to the bottom of the tank and the other one to the middle. there is a panel horstmann electronic 7 in the kitchen which should heat up water during off peak times.
i have been told that i should leave the bottom element switch on at all times and my panel in the kitchen and then it will come on every night to have hot water in the morning.i did so but i have noticed that if i leave them both on water is heating up all the time - not only at night .so everytime i use some water the tank is filling up and water is heated again.where is the problem?i have called many people but nobody can really help me :(

[honestjohn]

Karlaa86, You may find the following useful, http://www.horstmann.co.uk/downloads/El ... rGuide.PDF

You will see that if the horstmann controller is powering your immersion heater then there should be a neon (orange) light on.
First check that the horstmann unit is switched to timed

If a light is on during the day it could be:

The clock is set incorrectly, see display
The timings for when the power should be on are incorrectly set, see user guide on how to display and alter (use set b/utton)
A timed boost period has been set, unlikely but see user guide etc
The unit is faulty

If a light is not on:

The lower immersion switch may not be fed from the horstmann controller, switch the horstman unit to off and see if the water reheats.

A tank with a lower element will hold a considerable amount of hot water and will automatically be topped up with cold when any is used. Are you sure the immersion is switching on again when you have used some hot water? Sometimes you can hear the immersion heater heating the water is this how you Know or is there an indicator lamp in the lower switch?

I assume that you leave the middle immersion off?

Let us know if you have solved the problem