Immersion Heaters advice.

[dlt27]

Can anybody help.
I have been to various call outs for faulty immersion heaters. Now I know how to test stat, element etc. and how to sort the problem, but what I could do with somebody explaining is why some heaters have a built in reset button and some don't, why some stats have a built in reset button and some don't.

The other day I went to one where the stat had gone (sunvic). I replaced the stat like for like however the stat nor element had a reset buton. Aswell as the immersion heater the water is heated by a rayburn so I was wondering what happens if the rayburn heats the water above the thermal cutout of the stat. (Am I right in thinking these stats are non resetable or do they reset themselves when the water cools down).
The stat has a dial to turn it upto 70 degrees. However I thought now the cutouts were designed to operate if the water went above 55 degrees. Any advice would be appreciated.

 

[Welchyboy1]

The cut outs are a new safety requirement and they all should be fitted with them now

its for protection if the stat fails, if example there is plastic tank and the stat fails then the hot water can literally boil and melt the tank

this is a c2 on an eicr

they are a total pain though and i have had a few call backs due to them popping

 

[dlt27]

Does this mean that stats and elements shouldn't have a reset button and if so what happens with the scenario with the rayburn. I will be changing the stat every week. Thanks.

 

[dlt27]

Just looked on sunvic website and they do a resetable and non resetable.version. If it is a safety requirement why do they do a resetable version?..

 

[Guitarist]

As already said, it's a backup.
DO NOT fit stats which do not have the additional thermal overload, unless there is a separate unit already fitted.
As with everything, make sure you know exactly what's required before doing anything.

 

[oldtimer]

Mmmmmm well here goes first thing how do you C2 an immersion if it does not have a safety cut out stat my understanding is if it was fitted before the changes then its ok.

So lets start in England the standard is to vent the expansion pipe into the cold water tank which was fine and a common fault on immersions was that the contacts of the control stat would weld together so instead of cutting out they would just boil the water in the tank ie like a big kettle.

Now you note that I said England as up here in Scotland the expansion pipe is vented to the outside ie by means of a swan neck pipe on the roof so it it happens up here the steam vent outside.

Anyway in England it vents to the cold water tank but if this tank is changed to plastic then the tank will burst as the water boils and sadly that happened and a baby died as a tank burst . So the idea was to fit a high limit cut out hence the the 2 different type and as my understanding is when a stat fails then it gets changed to a safety cut out type . Now I do a lot of rental repairs so thats what I do as this applies up here and the same goes for smoke detectors ie its ok to use a battery unit but if it fails then it must be replaced by a mains / battery model.

Common faults in immersions are 1. Control stat as this is in constant use so useally first to go 2. Control or isolation switch again as there is a load across it they can fail through slack connections or wear and tear over the year 3. Immersion element very rare for me as the previous 2 are common so if I get 20 in a year then I find about 2 elements need replaced.

Off Peak can be a pain in twin element tanks because if the bottom thermostat fails then it can trip but also it can and will trip the top or the boost element. So how do you test the off peak one well I do it at the off peak board as the standard immersion measures 18-19 ohms so if you get that at the board then all is well

 

[Welchyboy1]

Mmmmmm well here goes first thing how do you C2 an immersion if it does not have a safety cut out stat my understanding is if it was fitted before the changes then its ok.

dont laugh but it was in the nic periodic testing book..........but also the esc guide to pirs or something and wether its retro or not it is potentially dangerous, and its not an uncommon event for the contacts to weld together especially off peak stats

C3 for non protected stats c2 for non protected stats with a plastic tank

for the sake of a fiver for a new stat i would personally change it

 

[SJD]

Issue 3 of the ESC guide #4 states to give a C2 if "Immersion heater does not comply with BS EN 60335-2-73 (that is, it does not have a built-in cut-out that will operate if the stored water temperature reaches 98 °C if the thermostat fails), and the cold water storage tank is plastic".

The ESC guide doesn't seem to mention giving a C3 for a non-protected stat in a metal tank, perhaps it should.

 

[oldtimer]

dont laugh but it was in the nic periodic testing book..........but also the esc guide to pirs or something and wether its retro or not it is potentially dangerous, and its not an uncommon event for the contacts to weld together especially off peak stats

C3 for non protected stats c2 for non protected stats with a plastic tank

for the sake of a fiver for a new stat i would personally change it

Well if its in NIC booklet then it has to be true lol

But seriously a recommendation yes but a potential danger I DONT THINK why because that system has been in place for about 50 years so here ia an analogy for you a guy brings in a vintage car to a MOT garage the car has neither airbags or seat belts now yes the car could be seen as potentially dangerous but the MOT guy cannot fail the car because it was built to the relavent standard at the time.

So if you are doing an EICR you don't have the right to demand that RCD protection is fitted if the installation complies and at the same time you NIC or any scheme member and you could be sued because you "think" the thermostat should be changed because a lawyer would sit you down and say can you show me where in the law or regulations that say it is manditory to replace the stat ? So sorry that wont wash dont get me wrong of course I would like to see all these stats get changed I would like to see mains/battery smoke alarms fitted I would like to see RCD protection but it aint going to happen because there is NO law to say we have to do it.

One piece of advise for you write do not speak to NIC and ask them is it manditory to fail a property ie C2 it if the thermostat has no safety cut out and if they are saying this is the case then will they pick up the tab if the customer takes legal action against you or your firm for misleading them. Me thinks the reply you will get is "Although it is not manditory to replace these stats to safety cut out models we would recommend that you bring this to the attention of the owner and also highlight it on your EICR"

 

[Guitarist]

I think that this has become a bit of a priority due to the number of deaths in the last few years caused by boiling water cascading onto people, usually sleeping at the time. The last one I read about was of a baby who had died in his cot when the plastic tank melted above his bedroom.
Personally, I see this as quite serious and it's one of the few cases where I wouldn't use the old "it's been ok like that for years" quote.

 

[oldtimer]

I think that this has become a bit of a priority due to the number of deaths in the last few years caused by boiling water cascading onto people, usually sleeping at the time. The last one I read about was of a baby who had died in his cot when the plastic tank melted above his bedroom.
Personally, I see this as quite serious and it's one of the few cases where I wouldn't use the old "it's been ok like that for years" quote.

I don't dispute it and' yes I would like to see them all changed but again we need to take care as legally we do not have a right to demand the customer does so don't get me wrong yes recommend it gets changed and like me carry stats so you can offer the customer to change it fine. But like RCD yo cannot fail the installation

Care needs to be taken here like a policeman who issues yo with a ticket he has to abide by the law plus it worries me that some people think they are god because they think they have a legal right to force the owner to comply

Just to add up here we don't have this problem as the expansion pipe is vented to outside and like the vintage car scenario yes I want to see seat belts but I cannot force the issue

 

[Guitarist]

I have found that when I "strongly recommend" something, and provided that it's not very expensive, the customer will 9 times out of 10 have it done.
An EICR is one thing, but when it comes to doing any work on a system that doesn't have a safety stat, I simply tell the customer that if they want me to do the work then it needs changing. That way, the customer makes the decision.

 

[oldtimer]

I mentioned this before where a landlord was told he had to have RCD protection to rent out his property after an EICR. So he demanded a full refund for the EICR and the new CU or he would take legal action for fraud and deception and he got it.

If thousands of people died every year due to faulty thermostats then it would be manditory but like you I can only recommend. Although these stat are fitted to new properties and ripped out when the property is converted to a combi boiler they are getting changed through stealth even when I go to a immersion that is faulty and the plumber has to change it (I am not insured for water) I asked him about this and he said that when he fits a new element a safety stat is already fitted so either way it does get changed the same as CUs yep lot of old ones out there but they will all eventually get changed

 

[Guitarist]

When I queried my insurance about plumbing, they stated that as long it was plumbing work carried out in conjunction with an electrical job (such as changing an element) then I was covered.

 

[Welchyboy1]

i think your going a bit far really

everyone has there own views and ways of doing things, i personally would consider that condition dangerous, and was probably installed in such a way long ago and the fault in the setup was only realised after people had got hurt

for the sake of the cost of a stat and 5 mins to fit im sure none of my customers would sue me for it when i explained the possible dangers