Domestic PIR - extent of immersion heater inspection & testing

[SW1970]

Hi folks, when carrying out a domestic PIR, do you include an inspection of the central heating immersion heater for old style single contact type? (Of course assuming that fixed wiring up to the immersion is tested as normal). If yes:

1. If it is old style single contact, what code would you give? (Feels like a 4 but because of potential danger might be a 2?)

2. Do you recommend replacement immersion to include a latching over temp thermostat contact by an electrician or that it should be done by a central heating engineer or either, or do you simply recommend that it is inspected by a competent person in central heating matters?

3. If the immersion is fed by an FCU (because it previously was supplied from a ring final circuit), but is now correctly supplied by a dedicated radial, but still has the FCU in place, am I right in thinking that the FCU should be replaced with a DP isolator, and therefore the wiring up to the appliance (the immersion head) must also be tested?

There was a thread on another forum about this a few years ago but was referring to 16th. Many thanks, SW

 

[miner69er]

the old style immersions are mentioned in the IET guide to PIR's and if i remember right are a code 2 as it could just keep boiling the tank, which if you've ever touched copper at 100 celcius you will leave a lovely palm sized piece of skin there...! (that is dangerous to all you S&M fans out there!!)
regarding the fcu. an fcu is normally a double poled switch anyway (under normal circumstance anyway) and yes that wiring should be tested as well.
hope that was helpful to you

 

[SW1970]

Hi, many thanks! Any thoughts on my Q2 above? Cheers, SW

 

[telectrix]

it takes about 3 minutes to swap the stat for one with an overheat cut-out. i'd do it while i had the lid off.

 

[miner69er]

agree with telectrix. recommend replacement or if you have time and customer agree's, do it there and then

 

[PC Electrics]

non-safety stats are a code 2 in the ESC guide and should be replaced (esp if it's rented). A young girl was killed by one a couple of years back, when a 50 gal tank of boiling water came through her bedroom ceiling. It was a council property too, that had been refurbished!!!

FYI most fcus are single pole - check it with your tester next time you have one in your hand!!
I don't replace fcus with a switch as a matter of course, unless I'm replacing the immersion in which case it gets a new switch and flex too.

 

[malcolmsanford]

non-safety stats are a code 2 in the ESC guide and should be replaced (esp if it's rented). A young girl was killed by one a couple of years back, when a 50 gal tank of boiling water came through her bedroom ceiling. It was a council property too, that had been refurbished!!!

FYI most fcus are single pole - check it with your tester next time you have one in your hand!!
I don't replace fcus with a switch as a matter of course, unless I'm replacing the immersion in which case it gets a new switch and flex too.

I know that the non switched FCU are often single pole but I always thought that the majority rather than a minority of switched FCU were double pole, but I live and learn

 

[Guest123]

Old style immersions get a C2 (PIR) from me.

I always reccomend replacement for a new one with the relevant stat/overheat protection etc which I do myself also.

I find once you explain the possible consequences to the client, they are happy you did.

 

[gooner85]

i agree with Lenny, as soon as you explain to the customer the consequences of not having a safety cut out, they want it there and then

 

[oldtimer]

Guys I hate to disagree but coding an immersion as a 2 because it has its original stat fitted does not add up for me my understanding is as our regs are not retrospective because if they were we would all be loaded with all the sorry this is not up to the current standards you will have to get it fixed so next time your are in a house with 3036 fuses or CBs but no RCD again this is not a fail. I myself have been called out twice to 2 properties that were built just before the regulations changed and reported to the owner or landlord yep your thermostat is not working I carry a spare 7"" and 18"" in the motor I will have to replace it and be advised it is the new safety model that has a high temperature trip built in so that now your property complies or in other words it was as our American cousins say Grandadded in and the new regs come into affect when "Alterations or modifications take place"

 

[SW1970]

That's right, but it depends on what is the reason for the PIR being carried out. Quite often I find the domestic client wants to know "if it's safe". To me, that translates to: "to ascertain compliance with current regulations". The reason I take that approach is because it was probably safe when it was installed, and therefore unless something has failed, it still is safe, but the regs have changed and now it could be safer. Client is usually happy to compare with current regs after that discussion.

 

[i=p/u]

So to change the stat do you need to empty the tank and change the elements too. As in 1 unit??? My mothers house water goes over 100 degress... Bet ya old type with no stat in

 

[malcolmsanford]

I have to admit that I'm a bit of a Saltie (Marvo may know what i mean here) about the immersion heater and a code 2.

If we apply the logic of it then the most it should be is a 4 and that to reg 554.2.1 concerning the prevention of temperature rise and the use of a device to prevent it.

The thing with immersions is that the ESC have guided us to give an immersion without a hi-limit stat a code 2 and if we depart from their guidance, and something happened we would not win the argument that it was at most, a code 4. So we code it a 2 and I don't think we have much option.

 

[Guest123]

Guys I hate to disagree but coding an immersion as a 2 because it has its original stat fitted does not add up for me my understanding is as our regs are not retrospective because if they were we would all be loaded with all the sorry this is not up to the current standards you will have to get it fixed so next time your are in a house with 3036 fuses or CBs but no RCD again this is not a fail. I myself have been called out twice to 2 properties that were built just before the regulations changed and reported to the owner or landlord yep your thermostat is not working I carry a spare 7"" and 18"" in the motor I will have to replace it and be advised it is the new safety model that has a high temperature trip built in so that now your property complies or in other words it was as our American cousins say Grandadded in and the new regs come into affect when "Alterations or modifications take place"

The immersions I am referring to carry no stats at all therefore are inherently dangerous as no overheat protection at all is offered.

 

[Jurassic Spark]

There's no requirement to have a t/stat with safety overheat in place unless the storage tank is plastic in which case a code 2 would be appropriate.

 

[oldtimer]

There's no requirement to have a t/stat with safety overheat in place unless the storage tank is plastic in which case a code 2 would be appropriate.

Guys me think why this has all come about was that a baby died when the stat on an immersion stuck on make for heat so essentially the immersion became a big kettle with the expantion vent releasing into a plastic cold water tank now to drift off a bit here in Scotland where I live the expantion pipe is vented to the outside hence why you see a lot of green "swan kneck" pipes on the roofs now my understanding is that in England (correct me if I have this wrong) it was seen as acceptable to vent the pipe into the cold water tank that at the time would have been lead or galvinised it was only the introduction of plastic where this problem was highlighted.

Lenny you are correct about immersions with no control stat but I must admit just like the shared neutral problem I in my 36 years have never come across both until last month where I helped another spark out as he could not understand why the RCD was tripping when he switched the hall light on.

So if there is no stat then yes this is a problem but if there is a stat and the owner reports that it works fine then I dont think its even a 4 because if you log it as that then were back to stating the obvious with the other 4 fav which is "No RCD protection" so to finish off I certanly would not grade a Unsatisfactory PIR on a installation that that essentially was acceptable at the time standards wise

 

[Jurassic Spark]

In my opinion the parents of that baby should have been charged with negligence. There's no way that a boiling immersion heater can be mistaken as it would be like a giant kettle banging and crashing the pipe-work. Obviously didn't have the wit or common sense to turn it off and get it checked out.

 

[oldtimer]

In my opinion the parents of that baby should have been charged with negligence. There's no way that a boiling immersion heater can be mistaken as it would be like a giant kettle banging and crashing the pipe-work. Obviously didn't have the wit or common sense to turn it off and get it checked out.

This all very well for you to say they were a young couple and non technical they switched the immersion on in good faith and yes they even reported that the water was scalding hot but going to your bed with the immersion on in any other case it would have reached control temp and cut out then cycled on and off all night as it should have this as we know didnt the water in the plastic tank heated up then the tank burst and the infants bedroom was directly below but as you say common sense if we all had it we would not need half or even any of the safety features we have today so a death of an infant in this case is not a point the finger scenario yes we live in a blame culture but I for one would say they were in the wrong place at the wrong time or in other words fate