Triton T90i Only Heats Water On Low + No Power Light

steo2k9

Hi. My grandmother has a Triton T90i which just went cold mid shower. I came over to have a look at it and the pump works fine. The power light doesn't even come on on the unit itself, but I found out that when it's on low the element still kicks in, then when medium or high is just stops and you hear the sound of the pump getting higher (as the elements have shut off). Is there more than one element in the unit or does anyone else know what might be wrong?

Idioteque

Have a look at this guys vids https://www.youtube.com/user/showerdoc ..he has one on most common problems from memory and I think your problem is covered

Sleeper12

It's bad news I'm afraid.

Your Triton T90i is 20 to 28 years old. They stopped making parts for this model 12 or 13 years ago. There are two elements in a sealed heating can. It sounds like you are operating on one element.

Even if you could get the part (you won't) you are looking at 150 supplied & fitted. The average life span of an electric shower is 10 years. The reason they stop making parts for old electric showers is that with years of use the heat from the element transfers to the cables. This drys them out & they become much more likely to go on fire. Unless you have your electric shower checked every year or two, you should replace it after 15 years for safety sake.

A new triton t90sr is around 330 to 360 supplied & fitted in the Dublin area. More expensive outside of Dublin. You might need to change the rcbo on the fuseboad too.

steo2k9

Sleeper12 wrote: »

It's bad news I'm afraid.

Your Triton T90i is 20 to 28 years old. They stopped making parts for this model 12 or 13 years ago. There are two elements in a sealed heating can. It sounds like you are operating on one element.

Even if you could get the part (you won't) you are looking at 150 supplied & fitted. The average life span of an electric shower is 10 years. The reason they stop making parts for old electric showers is that with years of use the heat from the element transfers to the cables. This drys them out & they become much more likely to go on fire. Unless you have your electric shower checked every year or two, you should replace it after 15 years for safety sake.

A new triton t90sr is around 330 to 360 supplied & fitted in the Dublin area. More expensive outside of Dublin. You might need to change the rcbo on the fuseboad too.

I can get the elements from a guy which presumably are second hand, but as long as they work it's fine. The neutral cable in that shower switch was also burnt a while back, I had to cut the end off it and fit a new switch, but I'm putting that down to bad tightening of the cable by the cowboy who fitted the previous switch.

We have our T90si about 10 years and when it broke, I just replaced the brushes in the pump. I've checked the cables in both the switch and shower, both were fine with no signs of melting. I do understand that the load being carried is extremely high, but I don't expect any fires unless people use the wrong cable such as 6mm instead of 10mm or else use a really underrated switch.

I guess for safety reasons what you're saying makes sense, but I know the wiring on ours is definitely fine, however, I'll find out what the story is inside the cover of her T90i tomorrow. Hers is definitely much older than ours and the house would have been much more damp than ours over the years too.

Edit: Oh you mean the wires in the shower unit itself, that would make a lot more sense.

Sleeper12

Your t90si is 12 to 19 years old.

You'd be nuts to buy 2nd hand heating cans on done deal caked with 25 years worth of limescale. The t90i is now becoming a fire hazard. You are leaving yourself wide open if something happens.

I repair showers for a living. Not in a million years would I have such an old electric shower in my mother's house. Old electric showers can go up in flames in seconds. I have dozens of photos of the damaged caused. The trip switch usually does not trip in the case of fire as its designed to prevent electric shock not detect fire.

The model after your mams is the t90si. This is obsolete too. Triton stopped selling parts for this 4 or 5 years ago. The model after that was the t90xr. They have stopped making parts for this model too. They stop making parts because old showers can be fire hazard.

I've bored you long enough. My advice is to replace it & get an electrician to check the trip switch, cable and pull cord switch. After 20 /30 years there could well be issues with these.

steo2k9

I believe that yes, but our T90si is not even nearly as old as the T90i that she has. We used to have a Heatrae Sadia shower before and it only lasted about 5 years before the heating element gave up. The guy who knew what was wrong made us buy a new shower and then took that to sell it to someone else without telling us that it could be fixed. Ours is still fairly old and at this stage they have silent pumped showers. My dad is always really paranoid about that stuff, but he always seems to think it's the switch that will go on fire. If a new shower would be safer then I have no problem getting ours replaced in the near future, but I don't want to make him any more paranoid than he already is about electric fires. He thinks a few things which draw low amperage plugged into an outlet would cause a fire when clearly the load is really low. Most showers are close to 10kw, which is at least 20 times the power draw from what powerful PC's and TV's both put together are drawing from an outlet.

Anyway yeah, the breakers usually just detect a short so it will do nothing when a wire is melting, I understand that too. I have no problem replacing the pull cord switch myself, which I recently have due to a mechanical fault, but it's just the trip switch I wouldn't go near because you can't isolate it.

EDIT: Also with our T90si, we have always ran it on cold for a few seconds after we've finished using it.

steo2k9

Just out of curiosity I've tested the elements and they're both working according to my multimeter. This means the problem lies in a switch. I think they'll be getting a new shower eventually but they haven't got a lot of money so it would be nice to just get this to work for the time being if it's only something small.

Sleeper12

steo2k9 wrote: »

Just out of curiosity I've tested the elements and they're both working according to my multimeter. This means the problem lies in a switch. I think they'll be getting a new shower eventually but they haven't got a lot of money so it would be nice to just get this to work for the time being if it's only something small.

They stopped making the Triton T90i around 20 years ago. They stopped making parts around 13 years ago. You won't source new parts for this model because it's not safe to repair without an electrician checking it out first.


I won't be giving any advise on repairs as it can be a death trap. My professional advice & Triton's professional advice is to replace it & don't attempt repairs

EDIT: Triton's number 01 6286845 Ring them & ask is it safe to repair this shower

steo2k9

Sleeper12 wrote: »

They stopped making the Triton T90i around 20 years ago. They stopped making parts around 13 years ago. You won't source new parts for this model because it's not safe to repair without an electrician checking it out first.


I won't be giving any advise on repairs as it can be a death trap. My professional advice & Triton's professional advice is to replace it & don't attempt repairs

I guess mine was different since it was only the carbon brushes, but I'm really surprised the brushes haven't worn yet in the T90i with it being that old. It was actually you that told me it was the carbon brushes funny enough.

She'll have no choice but to just go without one for now. Even when they can afford one, I'm good with electronics, but plumbing is not something I've done very much of either. I assume with the inlet being in the same place on most Triton showers, it wouldn't be that hard.

Sleeper12

steo2k9 wrote: »

I guess mine was different since it was only the carbon brushes, but I'm really surprised the brushes haven't worn yet in the T90i with it being that old. It was actually you that told me it was the carbon brushes funny enough.

She'll have no choice but to just go without one for now. Even when they can afford one, I'm good with electronics, but plumbing is not something I've done very much of either. I assume with the inlet being in the same place on most Triton showers, it wouldn't be that hard.

It's not a DIY job &and against the law for you to work on a shower

steo2k9

Sleeper12 wrote: »

It's not a DIY job &and against the law for you to work on a shower

Since when is this? You told me last year what parts I'd need and what could be wrong etc. which is how I fixed the T90si, so I just wonder why you're completely against that now. Sure they can get someone else to do it anyway but I do know what I'm doing when it comes to electronics and I've even had to change those pull cords a few times when they failed. I assume people were using them to switch on the load.

Sleeper12

steo2k9 wrote:

Since when is this? You told me last year what parts I'd need and what could be wrong etc. which is how I fixed the T90si, so I just wonder why you're completely against that now. Sure they can get someone else to do it anyway but I do know what I'm doing when it comes to electronics and I've even had to change those pull cords a few times when they failed. I assume people were using them to switch on the load.

I give advice when someone asks but never said it was legal. I don't give advice on old showers because its safer to replace. In my job I don't repair showers over 10 years old either.
It's illegal for you to replace pull cords too believe it or not.

steo2k9

Sleeper12 wrote: »

I give advice when someone asks but never said it was legal. I don't give advice on old showers because its safer to replace. In my job I don't repair showers over 10 years old either.
It's illegal for you to replace pull cords too believe it or not.

Wow! I know it's not your decision but I think that's actually ridiculous, especially if it's someone that knows what they're doing with electronics. Not everyone has enough money to fork it all out over something as simple as replacing a pull cord. It's as simple as changing a plug except that you need to be absolutely sure the terminals are fastened securely, otherwise it'll cause arcing and the wires will melt.

Anyway I'll get them to just buy a new one and since the T90si in my house is working, we'll leave it for the time being. We will replace it within the next couple of years either way. We actually bought the T90si when it was end of line about 11-12 years ago, but it's still been that long regardless, so it wouldn't hurt to get a new one. I actually think it's cool that the T90sr is silent pumped tbh.

antiskeptic

Sleeper12 wrote: »

It's illegal for you to replace pull cords too believe it or not.

It is? I thought like for like was okay. From the HSA site

“Like for like” replacements of switches, sockets, lighting fittings and/or additions to an existing circuit is frequently carried out in this country. While this must also be in compliance with the Technical Rules, these types of electrical works sit outside the Defined Scope of Controlled Works or Restricted Works.

A pull cord being a switch....

Sleeper12

antiskeptic wrote:

It is? I thought like for like was okay. From the HSA site

Satety Ireland and the commission for energy regulation disagree.

antiskeptic

Sleeper12 wrote: »

Satety Ireland and the commission for energy regulation disagree.

So if someone read a statutory agencies website and follows the advice therein they could nevertheless be prosecuted? I detect a loophole through which a bus could drive.


Who are Safety Ireland? I'm just getting some private looking general training company. And the Commission for Energy Regulation seem to deal with energy supply (fair pricing and the like). There's no mention of electrical installations on their site that I can see


I'd be interested in what can and can't be done - given I tend to put my repair hand to things from time to time. Who gives the definitive (and official) guide?

steo2k9

Same as myself, I repair a lot of stuff but it's mostly computers and phones I work with. That's honestly the first I've heard of it. I thought you just weren't supposed to service a gas boiler, and also Woodies DIY sell showers which aren't DIY so they're contradicting themselves lol.

antiskeptic

steo2k9 wrote: »

Same as myself, I repair a lot of stuff but it's mostly computers and phones I work with. That's honestly the first I've heard of it. I thought you just weren't supposed to service a gas boiler, and also Woodies DIY sell showers which aren't DIY so they're contradicting themselves lol.

I've gotten as far as there being minor electrical works which you are permitted to do .. but no one seems to want to publish them, not SafeElectric nor the Commission for the regulation of utilities (who are the bodies I think were being referred to by sleeper12.

This far I've gotten.

"Minor Electrical Works generally involve the “like for like” replacement of switches, sockets, lighting fittings, moving light fittings without affecting the circuit, and adding a socket to an existing circuit. The work must be in compliance with the National Wiring Rules."

So, when your hardwired hob goes, you disconnect it and put a suitable socket on the end of the wire (adding a socket to an existing circuit). Then run a wire from the new hob to a plug - rendering the hob a non-fixed installation

antiskeptic

steo2k9 wrote: »

Same as myself, I repair a lot of stuff but it's mostly computers and phones I work with. That's honestly the first I've heard of it. I thought you just weren't supposed to service a gas boiler, and also Woodies DIY sell showers which aren't DIY so they're contradicting themselves lol.

I dug this up elsewhere on boards. A moderator wrote to the CER to get clarification:

Question from Mod

The installation of heating controls downstream of a spur outlet. This would include a mains voltage stat downstairs, upstairs, on the hot water tank, 3 zone valves (generally in the hot-press), a three channel time clock, all associated cabling and connection to the boiler itself. I have attached a wiring diagram that shows a wiring arrangement. Would a registered gas installer be permitted to install this?


Answer from CER

If a new/clean circuit is required for these controls then this would fall under Restricted Electrical Works (REW) and can only be completed by a REC, however, the rules, that these systems are installed to, (IS813 and manufactures recommendations) state for an existing premises, a circuit may be spurred off a local suitable circuit. Under our definition of Restricted Electrical Works, minor electrical works are exempt as set out in CER/13/147 decision paper, see section 2.5. This means Non-RECs may carry out minor electrical works which would be spurring off an existing circuit to provide for heating controls if completing in an existing system.

So, you could do all this electrical work yourself. And you can certainly change a pull cord given it's a like for like switch change.

The rules (in so far as I can establish them) don't really exist.

"Examples" are given of the minor works that can be done (change a light switch or accessory, add a socket).

By giving examples, they are saying that the list of minor works isn't exhaustive

There is no exhaustive list published it seems

Which means the rules are merely indicative of what constitutes minor. Indicative in what way?

Well, complexity appears to be the only steer given: something relatively simple: like changing a light switch or adding a socket

But simple is in the eye of the beholder: there is nothing more complicated electrically in replacing an electrical shower vs adding a socket to a circuit.

So, unless the work is on the Restricted list, you could argue that it's included in minor works - so long as you consider it simple.

antiskeptic

Sleeper12 wrote: »

It's not a DIY job &and against the law for you to work on a shower

I'm not sure this is correct either. It's open to question whether you could install a replacement shower. But I don't see anything that says you can't work on one (i.e. repair it)

emeldc

antiskeptic wrote: »

I'm not sure this is correct either. It's open to question whether you could install a replacement shower. But I don't see anything that says you can't work on one (i.e. repair it)

Jack of all trades here :P
Whether it's legal or safe to do yourself really doesn't matter. If there's a fire you can be damn sure your insurance co will look at every excuse not to pay out.
I asked a Q about replacing a valve on a gas fire a while back and the thread was shut down because what I was trying to do was deemed illegal. I went ahead and fixed it anyway but nerves got the better of me and I had an RGI check it out anyway. Thankfully all was good but I understand where sleeper 12 is coming from.

Sleeper12

That's from the actual law; http://www.irishstatutebook.ie/eli/2013/si/264/made/en/pdf

This means that the sentence,
"the modification, installation or replacement of a Distribution Board
including customer tails on either side of the Main Protective Device
or of an Electrical Installation in any of the special locations listed in
Part 7 of the National Rules for Electrical Installations, as the case
may be;"

Part 7 is inside the bathroom or wet areas. Modification means repairs or replacements

Sleeper12

antiskeptic wrote:

I'd be interested in what can and can't be done - given I tend to put my repair hand to things from time to time. Who gives the definitive (and official) guide?

Almost anything in a bathroom is restricted works including the changing of certain bulbs in the wet area believe it or not. Not just electric showers themselves but the installation itself right back to the fusebox. This includes pull cord switch or isolation switch outside of the bathroom. Repairs to an electric shower is modifying it & is illegal. Power showers are the same. Anything electric in or near water is a no go area for the homeowner

There are threads on this but safe electric in their wisdom moved pages without a permanent redirect. I can't find the new pages.

steo2k9

I don't think it's that much of a priority, with all the crime in the area, the police aren't going to say "we have a report of a person working on a Triton shower" lol.

In all seriousness though, I know the idea is to not let a cowboy near stuff when they're not going to do the job right or just aren't competent to do so, but DIY shops are selling showers. I understand that you can't buy a gas boiler from a DIY store because it's highly illegal to go near one, but showers are easily available and really shouldn't be in a DIY store if it's illegal to install one.

I mean, if someone that doesn't know what they're doing does set their own house on fire then that's their fault, but I seriously am really good with electronics. I know how to fasten a terminal properly for starters. It's silly because I personally feel like that rule is only there for companies which install showers to make more money while the internals are actually very basic.

I'm not going to install one, but that has to be one of the silliest things I've ever heard. People are doing all sorts of illegal crap left right and centre and now they're saying fixing a shower is illegal? What next, it's illegal to not wear shoes outdoors?

Edit: I'm not directing this at you personally sleeper12 as I know you didn't make the rules, but I really just think it's a very stupid thing to be against the law. Once you isolate the power and water then the shower isn't really installed anymore and becomes an ornament, so I don't get why it's actually illegal. The power and water in the house don't have any other rule breaches such as changing a light switch or a faucet.

Sleeper12

steo2k9 wrote: »

I don't think it's that much of a priority, with all the crime in the area, the police aren't going to say "we have a report of a person working on a Triton shower" lol.

In all seriousness though, I know the idea is to not let a cowboy near stuff when they're not going to do the job right or just aren't competent to do so, but DIY shops are selling showers. I understand that you can't buy a gas boiler from a DIY store because it's highly illegal to go near one, but showers are easily available and really shouldn't be in a DIY store if it's illegal to install one.

I mean, if someone that doesn't know what they're doing does set their own house on fire then that's their fault, but I seriously am really good with electronics. I know how to fasten a terminal properly for starters. It's silly because I personally feel like that rule is only there for companies which install showers to make more money while the internals are actually very basic.

I'm not going to install one, but that has to be one of the silliest things I've ever heard. People are doing all sorts of illegal crap left right and centre and now they're saying fixing a shower is illegal? What next, it's illegal to not wear shoes outdoors?

Edit: I'm not directing this at you personally sleeper12 as I know you didn't make the rules, but I really just think it's a very stupid thing to be against the law. Once you isolate the power and water then the shower isn't really installed anymore and becomes an ornament, so I don't get why it's actually illegal. The power and water in the house don't have any other rule breaches such as changing a light switch or a faucet.

I'm not taking it personal. I've posted fact that are hard to believe. I totally get that. My own reaction would be to challenge these facts on first hearing them for the first time



There are safety tests required by law each time the the shower installation (anything from fuse box to shower itself) is modified. Modified is replaced or repaired. The pull cord or wall isolation switch are included in this. The safety checks insure that the RCBO will trip in the case of you being electrocuted. It's not that you don't know how to replace the pull cord. It's that you can't carry out the safety checks. It's confusing stuff. In the industry there is confusion as to what even a plumber can do in a bathroom. It doesn't help that all the relevant information has been moved online & it's harder to find. Their webmaster didn't redirect to the new page



Every few months I remind people of the law. It's important people have all of the facts.I sell shower parts online. 95% are bought by DIY people. It's up to them if they fit the parts themselves. We still give out advice here. A lot of advice given out here helps people decide if their shower should be repaired or replaced before they even call a tradesman. This makes it harder for the cowboys to push for a new shower when the homeowner knows it's c cheap repair.



Almost anything in the wet area is covered by this law including replacing the light bulb in parts of the bathroom. Can you imagine having to call an electrician to change a light bulb? Sometimes the law can be an ass.

antiskeptic

emeldc wrote: »

Whether it's legal or safe to do yourself really doesn't matter. If there's a fire you can be damn sure your insurance co will look at every excuse not to pay out.

If it's not illegal for you to do it then I can't see how an insurance company could withold payment. Indeed, after experiencing reticence on an insurance company's part to paying out after a chimney fire I found reading the terms and conditions of the insurance policy to be the solution. They paid.

They would need to exclude things in the terms and conditions, else they haven't a basis not to pay out. It is a contract after all.

antiskeptic

Sleeper12 wrote: »

That's from the actual law; http://www.irishstatutebook.ie/eli/2013/si/264/made/en/pdf

This means that the sentence,
"the modification, installation or replacement of a Distribution Board
including customer tails on either side of the Main Protective Device
or of an Electrical Installation in any of the special locations listed in
Part 7 of the National Rules for Electrical Installations, as the case
may be;"

Part 7 is inside the bathroom or wet areas. Modification means repairs or replacements

Here it is in fuller form.

4. (2) For the purposes of section 9E(1) of the Act ‘Designated Electrical
Works’ means:

(a) the installation, commissioning, inspection or testing of a new Electrical
Installation which is fixed, fastened or mounted or otherwise
secured so that its position does not change and requires connection
or re-connection to the distribution network or the transmission network,
as the case may be;

(b) the modification, installation or replacement of a Distribution Board
including customer tails on either side of the Main Protective Device
or of an Electrical Installation in any of the special locations listed in
Part 7 of the National Rules for Electrical Installations, as the case
may be;

(c) the installation or replacement of one or more circuits in an Electrical
Installation, including the installation of one or more additional protective
devices for such circuits on a Distribution Board; or

(d) the inspection, testing or certification of, or reporting on, existing
Electrical Installations covered by Part 6 of the National Rules for
Electrical Installations;

in a Domestic Property.



4. (3) For the purposes of section 9E(1) of the Act, ‘Designated Electrical
Works’ does not include:


(cuts out some irrelevant stuff here)

(g) Minor electrical works including the replacement of an electrical
accessory such as a light switch, the replacement or relocation of a
light fitting where the existing circuit is retained, the provision of an
additional socket to an existing radial circuit, or electrical works which
do not require the issuance of a completion certificate under section
9D of the Act.

I've experience of a similar situation: Revenue (law) state that all development (in a business context) on property is VAT taxable. Later they state that minor development won't attract tax. They go on to define minor development ( ie. the development costs don't exceed x percentage of the sale price of the property). Notwithstanding the statement that all development is VAT-able, the later exclusion overrides the "all" statement.

In the above case you have to factor in what is excluded from designated works. The permission for minor works can be read as overriding the earlier exclusion.

I'd note too that there doesn't appear to be anything to prevent working on an appliance either (such a fixing or replacing a shower, oven, etc). The electrical installation is the fixed wiring infrastructure of the house - not the appliances attaching to that infrastructure. This is witnessed in the following designated electrical work

(c) the installation or replacement of one or more circuits in an Electrical Installation, including the installation of one or more additional protective devices for such circuits on a Distribution Board;

There is no mention anywhere, that I can see, about appliances attaching to the electrical installation.

-

Lastly, and something to be checked out. I was chatting to a registered electrician pal this morn. He was talking me through all the rules and regs and certification processes. He reckoned that the extra costs were simply going to increase the amount of back street electrical work as folk weren't going to pay and most would be ignorant of the law and faced with x times bills for simple things done around the house, they will simply ignore it.

In the course of the conversation he said that these rules don't apply to a homeowner working on his own home. That they applied to people carrying out work for money.

Worth digging into that one !

steo2k9

That's quite interesting and I think that makes more sense tbh. If a person wants to install a shower for others while not being qualified, then I can see why that rule applies and it's illegal. I see absolutely no reason why replacing electronics in your own home should be illegal, as you're literally carrying out the work for yourself. I guess it's similar to being a novice driver and going on the motorway, you're not qualified to do so, just like you're not qualified to fit showers for others.

If it's actually illegal to do it in your own house then I really just don't understand this country anymore.

I find it all extremely confusing and that's why I think it sounds ridiculous, like we've fit our own electrical outlets in the past, along with light switches and ceiling light fixtures, so where exactly do they draw the line then?

If safety checks are to check for loose, corroded or burnt wires then it's not really that complicated. The RCBO test though I can understand and our current one was actually installed after the shower when we had the fuse box replaced with switches.

antiskeptic

steo2k9 wrote: »

That's quite interesting and I think that makes more sense tbh. If a person wants to install a shower for others while not being qualified, then I can see why that rule applies and it's illegal. I see absolutely no reason why replacing electronics in your own home should be illegal, as you're literally carrying out the work for yourself. I guess it's similar to being a novice driver and going on the motorway, you're not qualified to do so, just like you're not qualified to fit showers for others.

If it's actually illegal to do it in your own house then I really just don't understand this country anymore.

I find it all extremely confusing and that's why I think it sounds ridiculous, like we've fit our own electrical outlets in the past, along with light switches and ceiling light fixtures, so where exactly do they draw the line then?

If safety checks are to check for loose, corroded or burnt wires then it's not really that complicated. The RCBO test though I can understand and our current one was actually installed after the shower when we had the fuse box replaced with switches.

According to my electrician friend, whose livelihood is affected by this, it appears to be a land grab by vested interests (RECI). The whole certification/inspection thing brings income. The more you can include in the certification process, the more money rolls in.

There is logic for a homeowner being barred - it's not just the homeowner who is impacted himself, but also anyone using the home. Nevertheless, unless you bar a homeowner from any electrical work, the potential exists for a homeowner to do something with an electrical item that's dangerous. Where does it stop?

An uncle of mine was interviewing the head of Boeing once. The CEO said that they could develop a plane that was so automated and safe that it was next to impossible for it to crash. "But then noone could afford to fly anymore". The reality is that there's a cost/benefit in these things: you can only go so far in the effort to save lives (be it the health service, car safety systems, etc). Which puts a € cost on life.

Is the extra cost on the whole nation, brought about by all this certification work, worth the savings in life? There has to be a limit on it.

antiskeptic

https://www.hsa.ie/eng/Topics/Electricity/Dangers_of_Electricity/Electrical_Fatality_Statistics/

It would appear that 19 people have been killed in non-work related electrocution event since 1997. That's less than one a year.

Reading what happened you see heaters, washing machine, lighting tower, cutting through a cable with a hacksaw and the like. Appliances and one you couldn't protect against.

Electrocution due to fault in the fixed wire installation (which is what these regs cover) is virtually zero.

Yet millions of euro are being shelled out by homeowners, to prevent deaths that don't actually occur due to same?

-

I suppose house fires can occur from faulty wiring too. But would suspect that the deaths/damage to property is similarly negligible

steo2k9

Most of these house fires are caused by people buying cheap Chinese AC adapters which are extremely dangerous. Those transformers can be a death trap in those extremely cheap ones.

As I said also, the neutral wire was melted in the switch which leads to the shower unit itself, which explains why it used to not work sometimes and then kick in. That wire was either never properly tightened or came loose over time and was never checked. Nevertheless, it didn't go on fire even though it had been like that a long time, all it done was melted the insulation for about an inch on the neutral cable. I know that it could have went on fire, but it didn't, and that's why I think so long as the cables are checked then there's not really a fire risk. I doubt perfect cables that are checked would start a fire if a cable that's been arcing for years carrying an 8.5kw load didn't.

I think the biggest reason to have a fire is using cable that's not up to spec which is too thin, so it overheats for the entire length, melts away the insulation and bursts into flames.