Stanton Immersion heater no hot water

RobDiver88

Hi all,

Looking for a little advice on a problem I'm having with my home water heater. It has recently stopped heating overnight, any info or guidance would be greatly appreciated. Blurb below.

I have a santon premier plus immersion heater installed in a cupboard in my flat, the set up being two thermostats. The bottom one for economy 7 heating during the night and the top one for boost, the switch for this being in the kitchen. Around June 17 the water stopped heating overnight so relied on the boost for hot water until around November when I had a spark come in and change the bottom thermostat in the tank. It seemed to work all fine, I ended up away with work for 3 months so it was only really tested for a week or so after it was fitted. When I go back to the flat in the middle of February it worked for the first 4 or 5 days before seeming to give up the ghost again and not heating water during the night.

I'm not sure if it makes a difference however I did turn all power and water off in the flat, both main supply and to the tank when I left mid November and when I came back turned it all back on and gave it a day so the hot water taps had warm water. Did notice the flow from the taps were a bit crazy for the first few minutes of running.

I noticed a slight whistling noise from the heater with this new thermostat, had a look online and general chat was possible build up/pressure problem. Flow seems to be fine from the discharge pipes though as I operated these to rule a blockage out. Had the thermostat covers off and tried jabbing in the reset buttons but still no luck.

Any guidance would be greatly appreciated as I don't want to put another thermostat in in case that's not the real problem and before getting a spark in to have another look.

Thanks.
Rob

Le_Kirk

When you changed the thermostat for the bottom heating element, how was it tested? Since it is economy 7, you or your electrician would have had to wait until it switched over at between midnight and one a.m. or come into the house and tested it before it turned off between seven and eight a.m. If it was tested properly and worked and is now not, I would suspect the element itself. Does the top element work?

RobDiver88

Hi,

To be honest I'm not entirely sure how he worked out it was the stat as he was outweigh the economy 7 times on both pre work and installation. He pretty much came up while I was away with work said it looked like the stat because the water was not not, ordered a new one and replaced it. After that the water was heating nicely during the night. I did notice a slight rise in the temperature of the water and the whistling noise from the cylinder. The top element (boost) has worked fine both times the bottom 1 has not heated.

Since this afternoon I have swapped the two stats around as they are the same, just to try rule it out. Put the boost on and am getting got water through that. Would that suggest it's not actually the thermostat if it's working on the boost? I also operated the drain valve and the other two dials and heard a slight knock.

Le_Kirk

As a way of fault finding, swapping parts around to see where the fault goes is perfectly sound and normal. However, when you have done that and proved it one way or the other, the difficult bit is knowing what to test next, particularly difficult with Economy 7. My next step (but I am experienced/competent/confident) would be to test the bottom element by using a meter - obviously with it switched off and/or disconnected. If you are not confident or competent then the answer is what is normally recommended in these circumstances, call in a qualified person.

southcoastrgi

So you left a tank full of water for 3 months in the middle of winter, I think you were lucky you did not come back to a split cylinder & a flooded home

RobDiver88

I've a meter and am able to test the element. If that does produce something abnormal then I may have to just bite the bullet and call in a pro, the reading I've done on changing an element I may sit that out...just in case. Pressure and electricity, not to be messed with man.

I did isolate the tank and drain it to an extent before I left in a bit of a rush, not ideal I know. Any idea as to why it wouldn't be working both originally and now?

Thanks

Le_Kirk

When testing (with the power cables disconnected) you will be looking for (as I am sure you know) a resistance across the element. If there is none, then it is open circuit and has failed. You might be lucky and the element is installed in a sleeve and can be withdrawn without having to empty the cylinder, if not you will be faced with a drain down and trying to unscrew the old immersion heater in its entirety. You will need a special box spanner and a hefty dose of a release agent and a good dollop of luck!

RobDiver88

Tested the heating element terminals and got a reading pf 20 ohms, which im told is normal. Also done a test early morning at 06:00 on the live and neautral terminals connected to the stat and suprisingly came up with a reading of 0 volts. On my consumer unit in cupboard a sticker marked ssc 23:30 - 07:30 so im guessing this is my economy 7 operating times.

Performed the same tests on the boost elemnt and terminals and showed 240v along with the element and stat being ok. I am now wondering if there is a fault durther back in the wiring and/or fuse box.

Thanks for the advice Le_Kirk.

David_Aston

On the matter of economy 7. It is a 7 hour span, not 8.
Also, it's operation alters by an hour with winter/summer time changes. Also, it can drift out of any theoretical norm, for instance, our night rate is between 3am and 10am at the mo'

RobDiver88

I see, i may take a few more readings through the night then to be certain before moving ahead. Thanks for the info.

thorganby

RobDiver88 wrote: »

Tested the heating element terminals and got a reading pf 20 ohms, which im told is normal. Also done a test early morning at 06:00 on the live and neautral terminals connected to the stat and suprisingly came up with a reading of 0 volts. On my consumer unit in cupboard a sticker marked ssc 23:30 - 07:30 so im guessing this is my economy 7 operating times.

Performed the same tests on the boost elemnt and terminals and showed 240v along with the element and stat being ok. I am now wondering if there is a fault durther back in the wiring and/or fuse box.

You have tested the lower immersion element but are not getting any power to it, so you need to post pictures of your meter showing the associated wiring and also of your consumer unit with the cover open because you may have a timeswitch fitted in your consumer unit that will now need setting after you have turned of the power to the flat. Pictures will show how your E7 is enabled for the seven hours e.g. if you have a meter/timeswitch/contactor or a separate timeswitch.