Immersion Heaters - How they work, fault finding & testing

[@DaveOxfordCookingWithStarlight]

Just wanted to say thank you. Excellent, methodical presentation. Instilled confidence. Tested and replaced a failed thermostat after watching. Kudos.

[@Xterminator4i]

Love the way emphasis is made on the last word of every SENTANCE!

[@therealjag]

Now I can't unhear it lol

[@nickmacdx]

What he said !

[@sndrcve]

Definitely some sort of police/army background methinks

[@CommercialGasEngineerVideos]

Very TRUE!

[@JbVest]

Oh gosh thanks for pointing that out now I can't ignore it 🤣

[@arthuredwards5747]

Huge thanks to John Ward for this video - I have just tested my immersion thermostat and found defective, so have bought a replacement and fitted without trouble. Probably saved £70+ plus many days waiting for a plumber. Brilliant !!!!

[@DavidWilliams-ov2kc]

We've got a solar thermal HW system, augmented by immersion heater & oil fired boiler. The immersion failed to heat the water yesterday. I wrongly assumed the immersion thermostat and/or heating coil had failed and was about to replace both; however your excellent presentation and detailed explanation saved me a lot of time and expense. Cause: On a sunny day a week ago, solar had pushed the tank temp up to > 90 C causing the immersion safety cut-out to trip. Solution: Press the little red immersion thermostat 'reset' button, and reduce the the solar thermostat max temp setting to 70 C to prevent future problems. Thanks a million for a really helpful video!!

[@davidsedlickas8222]

John I was very pleased to see your vlog. My immersion heater stopped working. I called out a plumber who advertised " no call out fee" He arrived with clip board in hand. I point out the tank. and he bent down to feel for a drain tap. Then he opened up his clip board and wanted my signature on a work sheet to agree to pay £125 per hour. Wow ! I backed off. Saying how long to fix the problems 2 hrs ! No I said I cannot afford £200 . Sent away I found one of your volgs John And re set the thermostat reset button It sprung back to life.

[@simonwinn-smith4972]

This is a superb video, thanks! I'm an electrician and due to my ignorance about how these things are put together I simply referred a job to a plumber I could have diagnosed and, almost certainly, fixed myself. Wonderful video.

[@gerardkeaveney3909]

I don't usually comment on videos but this was one of the most insightful videos I've ever watched👌👌👌

[@almartin727]

Knowledge worthy of the price of a pint. Thank you for sharing.

[@javcala545]

thank you very much. I am a spanish-french spark ( chispas) triying to understand the domestic ( and commercial) systems and different ways of wiring here( very different).I used to do commercial in france so I am a bit lost some times when we have to rush ( always unfortunately). When I came across a british electrician trying to reset to the french systems I would always offer my help and give him my phone since I speak english. I have been following your videos for three years now. Happy new year.

[@CommercialGasEngineerVideos]

The differences and similarities between commercial/domestic systems throughout the world as well as the laws are interesting.

[@thedeepsfix]

Thank you for saving my family an expensive repair bill. By following your video i confirmed my heater and thermostat were fine. I replaced the separate controller box which was under warranty still, and got the system working again! Good info thank you.

[@markytowers]

Thanks for making this video. I was able to fault find a problem with the thermostat and fix it rather than have to get a plumber to replace the whole immersion heater. A big thumbs up!

[@Guzzi_Pete]

Thank you John ! - My boiler is on the blink, and what a bad time to find out that the immersion heater doesn't work either ! By following your clear instructions I was able to diagnose a faulty thermostat and fit a replacement. Now we have hot water again. Again a thousand thank you's.

[@mikebakkeyt]

Excellent presentation and just what I needed. So much better than the normal quick-fire videos from many on here. Thank you.

[@hassanburrows8535]

+John Smith. Another excellent video J.W. Thank you. In one school where I worked, the building had formerly been a large private residence. The hot water cylinder was replenished from a cold water cistern in the roof which was constructed on site from a lead-lined wooden carcase. You could almost swim in it.The Health and Safety team came one day to do a routine check on the system and then suddenly the whole system was being replaced.The reason? Well not so much we were being slowly poisoned by the lead (don't fill the kettle from the hot tap!), but the inspectors found the remains of two dead pigeons floating in the uncovered cistern.Never seen the council move so fast in all my life!

[@CrazyMedic]

Thank you for this, I just found the fault with our Emerson Heater...... The Thermostat had failed and following your video, it was quickly found and fixed with an exchange thermostat... Thank you so much..... Keep up these awesomely informative videos

[@paulallum9503]

You are the main man John. You have a great grasp of the subject. I find all of your videos impart massive amounts of understandable information. Thanks for your contributions in helping normal householders understand there home systems and keep the sharks away.

[@emmams5]

All tutorials should be like this, good on you for taking the time and energy to educate the masses.

[@justmegt4495]

Excellent video. One of the best I have seen on You Tube. Anyone who thinks this is boring probably knows it all anyway. I knew how these work but didn't know about the reset buttons. I will be checking mine out tomorrow, No hot water. Thank you.

[@Sholay48]

Thank you John. Very comprehensive. You've left no stone unturned.

[@shaunsautorepairs5410]

Thanks JW. Im normaly only a car repair/diagnostic video watcher as im a mechanic by trade but if i need any plumbing sorted your my 1st port of call for imformation... Since watching your videos it has allowed me to change central heating parts, understand system operation and fault find when things go wrong.. Keep up the good work

[@goodpirate]

What a brilliant video, gave me just the confidence I needed to sort out my own immersion heater and you delivery made me smile all the way through.. Thank you!

[@BoomBoxDeluxe]

Aaaah, very good. I once had a popped heater and just out of curiosity, I took it out in the back garden and _"Opened-It-Up-Very-Carefully"_ with a hacksaw and hammer so that the heating wire could be revealed inside. :-) Yes, I did video it. Look for: *_"What's Inside? Immersion heater element, 240v, 3kW"_* and you'll see the vid on my channel. I kept the section of heating wire and in a later video (with a ballasted variac mind you) I powered it up and used it as a foam cutter to cut pieces of polystyrene. :-) Removing the section of heating wire was a challenge as I had to beat at the outer copper sheath to get the insulating agent out of there in order to release the heating wire. It didn't give up easily! But then...... I wasn't having it! I wanted a bit of heating wire so that I could make a hot wire foam cutter. :D Thanxx for showing, -BoomBoxDeluxe. _18th January 2016, 02.10_

[@tomschmidt381]

Always interesting seeing differences in electrical practice between US and UK. In the US larger tanks have two heating elements that are switched so only one is on at a time. Typical element rating is 3800 - 5500 watts. Lower element is normally rated at higher wattage. Interestingly in the US the heating element, thermostat and over tempt safety are separate devices located are under removable insulated panels to reduce standby heat loss. The heating element screws into the tank and the thermostats and over temp are held in contact with the tank with a spring clip. As with the UK due to the high power water heaters operate at 240 volts.

[@Electronica2025]

Thanks to this video 1 year of sitting with no hot water i got my meter changed to a monthly pay meter and its never worked since then and thought it was something to do with that however after watching this video i isolated the switch and ensured there was no power to the house and pressed the reset switch on the thermistat and yippeee its now working again so not sure what the chap did when he was changing our meter but may have tripped it anyways Thank you what got me worryed was your comment regarding the diseases relising that my hotwater taps do still give out water from that tap at normal temps so i have kids and dont want them washing there hands with that water or even worse drinking it! plus added benifit back to warm baths showers are great but just dont do it some times So happy

[@chrispotter8168]

Thanks for the detailed explanation. Had an issue with our gas boiler and turned the immersion heater on, but no hot water. Checked the reset switch and it has indeed popped out, pushed it back in and we are in business! Thanks again

[@starwatcher2001]

You are a star John. Your video has just saved me a lot of hassle. Thanks fella!

[@4rawgnas]

Mate, thanks so much for all of your vids. Just bought my first house and have been renting all my life. Now i have to know all this! Thanks!

[@maxtroy]

Amazing channel. Got to a job this morning and this video was exactly what I needed to know how to test the immersion. Thank you, you just helped me big time

[@mahmoodakhter1491]

Many , many thanks to you ,Mr John Ward.I followed your crystal clear instructions and managed to replace the faulty thermostat in my immersion heater.Thanks for explaining about the reset button.The new thermostat i have used has got the reset button on it..

[@TurboTel68]

Top vid John. We would only ever use Backer branded ones, but its been some years now since I've had to change one thankfully.

[@SteveMayne1]

Cheers John, on checking my thermostat of 70's vintage, it didn't t have a safety cut out. Immersion heater is connected to my new solar panels and excess electricity is routed to heat the domestic hot water. If we get a summer this year I can be safe in the knowledge that my cold water tank won't turn the top floor of our house into a impromptu scald-o-thon.

[@skeets2004]

Thanks very much, this just allowed me to temporarily get our immersion back up and running by resetting the stat. Will see if it trips oit again and replace the stat if so. But this has saved us from an emergency plumber visit on a Sunday

[@jamesgrimwood1285]

Being a kid growing up in the 80s and living in a house containing an immersion heater, I really don't miss the days of coming back from a holiday and having to "put the immersion on" for an hour or two before being able to have a bath. And the terror of "running out of hot water".

[@debbiesaunders1815]

@James Grimwood when I was growing up we didn’t even have immersion heaters, if we did my parents never used it. We had a fire in the kitchen that used to heat up the water so our house was always freezing cold (no radiators or storage heaters just real fires in downstairs only. I used to dread going home even from school as you knew how cold the house would be. We used to have to put on our coats when leaving the living room to go to the toilet in the house!!!! I don’t miss those days. Rich people have no idea what it’s like growing up poor!!!!!!!!

[@norwegiannationalist7678]

@@debbiesaunders1815 well rich people are rich for a reason.

[@avidsquarehead]

Thank you for explaining where to find the Re-set button on older models just after 9:00 mins in!

[@fall174fps]

(yes, I know it's 8 years old but I felt the need) This is a nice detailed analysis of a deceptively simple system. Every time I thought, say, "Ah, but he's forgotten about earth leakage", John would then go on to explain about earth leakage. I feel the need to buy an insulation tester now. Other wiring variations I can mention: - It's common (at least in Ireland, where we're still on imperial. Irish imperial of course, not British) to have one immersion unit but with dual heaters. In this case there's a "Sink/Bath" switch which toggles between two live connections. The neutral is common and is thus routed through the stat. Usually with brown leads to cause maximum confusion. There are of course a number of ways for idiots to wire this wrong, the best being where the stat is bypassed and both heaters are connected in series. - Those with very old electrical systems may not have RCDs. In which case current to earth may result in the immersion still being sort of functional. Or the outside of the copper tank being live. One of those anyway. With the added bonus that, in the case of the stat switching neutral, it will also eventually boil. Failures I have seen: 1) A plumber wired L and N directly to the immersion and left what amounted to a bomb in some poor sod's house. The plumber was called back and, get this, he actually replaced the stat, leaving the wiring as is! I told the guy to never hire this idiot again. Report him actually. 2) Apartment in my block with a failed (closed) stat for literally months. I could hear the boiling through the expansion pipe which ran up inside a wall into the common attic area. I reported it but they didn't do anything until the vibrations caused the expansion to shear off at a corner fitting. Cue the poor sod next door having hot water pour through his light fittings at 3am. 3) Staggeringly, another apartment then did the same thing while _knowing_ they had a failed stat! I threated to call the ESB and have their meter cut off on a Fire Safety basis. I saw them move then! 4) People who think it's grand to put a plug on the immersion lead and plug it into a timer. It's fine until it isn't.

[@foolonthehill5065]

Excellent video. Saved myself an expensive call out by resetting the thermostat. Thank you!

[@spexmaniacuk]

Thank you, this just saved me changingthe whole immersion heater, the fault was in the thermostat.

[@martinleithe8251]

Very helpful, Thank you. Did not know you could just take out the thermostat that easy. Thanks for the video !

[@joshuahaken2833]

Excellent video, my girlfriend is having an issue where her cylinder isn’t heating up at night. Upon further inspection the Rod wasn’t actually wired in. I then did your tests and there was no resistance between earth and the terminal. She then just used the boost function on thermostat and now that has packed in. Although that immersion rod seems fine…

[@wynjones1033]

Hi John, Just a little thank you in your explanations. You would be a top lecturer I'm sure if your not already one.

[@johnabiodun5540]

Best video on KZbin about immersion... and I've watched a few of them. Well done 👏

[@vijayvjn6874]

Breath of fresh air compared to the other moronic youtube channel trying to explain how this work, thank you for taking the time in making these videos,I found it concise in its description of all the failure modes

[@barryhickman4498]

Thank you John for taking the time to do these videos. I learnt a lot from the swa cable assembly video because your presentation is so good....Merry xmas to you and your family

[@lemoniejones]

Really clear and informative tutorial. Completely understood and went through the steps and managed to locate the problem and fix it. I never comment but this was a very good video.

[@THECARKUS]

JW. You are an absolute legend! Thanks.

[@jasonbillington3923]

absolutely brilliant video. I've watched a lot of your videos and I have learnt a-lot, so I have to say thank you for your knowledge. great videos as always.

[@mrbroccoli7395]

absolutely brilliantly presented, step by step leaving me totally confident to do it all.

[@jaygoodgame]

thanks to you I've just solved an abysmally annoying problem with my hot water. thanks very much

[@Recessio]

Great video, clear explanations. A tale about immersion heaters: I once rented a really rubbish old flat years ago, the cheap 13A Flex Outlet+Switch the heater was wired into, it couldn't handle running a 3kW heater and the internals of the switch used to melt after a few weeks of operation at night (economy 7). So I'd wake up to a tripped RCD, no hot water, and the horrible fishy burning smell of cheap electrics doing their best attempt to burn my flat down. Each time, the landlord replaced with another crappy plastic flex outlet, which after a few weeks would burn out... eventually I convinced him to buy a metal cased 13A flex outlet for better heat dissipation... instead he just got a cheap plastic switch again, but with a 20A fuse instead! I didn't dare stay in that flat much longer after that!

[@rosyapplekitchen635]

😮

[@fernandespeter9232]

Thanks John, for sharing this video of immersion heater testing.

[@dianapereira371]

Thank you! I thought I had a faulty element and thanks to your video I learned that I only had to press the "reset" button on the thermostat. I'll keep an eye on it but I won't be having to replace the whole element! :D

[@jwflame]

It will probably trip again and again - it's only there for when the main thermostat fails and the water gets too hot, so a new thermostat is almost inevitable.

[@davidparker4582]

Excellent video, many thanks John for this - really useful.

[@ScottieNiven]

In Ireland we have very similar setups, but we dont have cheaper electricity at night. There is usually 2 elements, but one will be a lower power than the other. One will be labeled "Sink" and one "Bath". This is so you can heat up enough water to do the dishes or to run a bath.

[@JohnSmith-ju4vw]

+ScottieNiven I suspect they don't run at different power levels, you will probably find that they are both around about 3KW, but I'm guessing that the element marked sink is probably at the top of the tank, so will heat the water in the top section rather fast, which will give you enough hot water to wash your face or do the dishes.

[@ScottieNiven]

+John Smith Both elements are in the same "unit" at the top of the tank at an angle, like JW showed in his diagram. They do run at different levels, I had to fix ours since the switch was accidentally wired backwards, so it was not heating corectly, and when the resistance was checked, they were different.

[@JohnSmith-ju4vw]

+ScottieNiven Interesting. But lets say that one was running at 1.5KW and one was running at 3KW, and like you said they are both in the same part of the tank, surely the 1.5KW one would take twice as long to heat the water, thus costing the same amount of money to run? Unless of course the one for doing the dishes or washing your face (1.5KW) is set to run at a lower temperature than the one being used to fill the bath, in which case it would reach its desired temperature a lot quicker, which would make sense I suppose.

[@ScottieNiven]

+John Smith The elements are different lengths, the high power one is long, reaching near the bottom, the lower power element is short, only about 1/2 the length. Like this: imgur.com/8a1Vg5W When the bath element is on, it will heat the entire tank and will take a couple of hours, where as the sink element will just heat the top portion of the tank much faster, as the hot water out is at the top. (Providing no one else uses the hot water while its heating)

[@JohnSmith-ju4vw]

+ScottieNiven I see. But that makes me think even more that both of your elements are rated at 3KW. In Scotland you can get three different sizes of elements. 11 inches, 18 inches and 24 inches if my memory serves me correctly. They're different lengths but are all rated at about 3KW. If you go and have a look at your tank now it should have their ratings on the cover, you won't even need to open them. I'm willing to hazard a guess that they're both the same, just different lengths.

[@AtlasofInfo]

We're having a loft tank and new immersion heater fitted as well as a pump to deal with a water pressure issue on our second floor. We already have an immersion heater on the first floor, which is on its 16A MCB. My question is, could I split the supply using a junction box from the one breaker on the consumer unit to the new immersion heater? Obviously, this saves the mess of installing a new cable all the way to the CU. We probably will never use them at the same time, unless by mistake, which is very unlikely.

[@michaelbuckley5059]

Another informative and excellently presentation. Well done John Ward

[@Ivan-ji7tb]

Thank you JW, another clear, and complete guide👍

[@yensabi]

Very informative as usual from you John , thanks

[@rezafard1]

very professional and useful video.I fixed my boiler after watching ur video. thank you very much

[@garrygemmell5676]

Always very informative John! Keep up the good work and save the amateur bodgers from killing themselves. Must get myself a Fluke 1653 ...nope just checked the price £320 wow!

[@techi60]

Cheers John my reset was separate from thermostat but I got the idea. Hot water returned. 👍🚿🌡

[@davidwade767]

Hi John, got a problem that is a bit unusual. The thermostat keeps cutting out on the safety cut out even though the water is lukewarm. There are no air locks and water flows freely via the hot taps. The plastic body of the thermostat gets really hot very quickly even though the pocket itself is cool. I have changed the thermostat but the new one does the same. When I short out the tehrmostat the heater works fine. Any ideas? Dave

[@suckdiesel7065]

Quite common where I live is the top mounted dual immersion heater. They have a long and a short element in one unit, giving the same functions of the two side mounted heaters. It was controlled by a 2-way switch, marked ‘sink’ and ‘bath’, and an on/off switch Are they uncommon in the UK?

[@nickwales2667]

Excellent explanation as usual John

[@corinlanser]

Very detailed and clear, have you worked on tv, perfect for tomorrow's world back in the day!

[@twowheelstouring482]

Great video John, I would never have thought of IR testing the element. 👍

[@bobbyblanco1118]

I've one possibly 2 more questions on Immersions, I'll get back to you with them. I'll double check them before I ask you. Cheers John

[@chrisshave7129]

Another immersive explanation JW thank you!

[@treforknight1033]

Very clear video - thanks .. I've just invested in my first multi-meter! .. identified immersion ok and thermostat shot.. in the process of replacing the thermostat - cheers.

[@thomashenry4210]

Another really helpful video. I was able to tell that the heating elements are fine, but that the old thermostat was not. However, now I'm confused about sizing. The old, Pullen, for a top fitting gold dot immersion, says 18 inches, and the rod itself measures 18 inches. However. the replacement I have just bought, (which was listed as 18 inches), is slightly shorter, being about 18 inches long including the top part, with the rod itself being about 16.75. Does this difference actually matter, and, if so, how do I track down something the same size? In addition, as the top part is rather bulkier too, it only fits in if I rotate it such that wires to it would have to be switched round, that is live and neutral. I assume that polarity here does not matter if it is just a switch, but thought that might be worth checking too.

[@jwflame]

Doesn't matter as long as it physically fits.

[@thomashenry4210]

@@jwflame Thanks John.Good to know.

[@debbiesaunders1815]

Thank you for such an interesting informative video including the potential dangers of legionnaires disease. I might have set the heating lower thinking I was saving money and could have died!!! Great video, now to find my screw driver and fix my hot water problem..,. I love KZbin for learning things

[@VAX1970]

I had a Backersafe Immersion Heater (3KW) that lasted 24 years using it every day for 2 hrs in softened water .. British Quality!

[@rossmurdoch7870]

Another concise professional explanation John, many thanks

[@tomadam4102]

That was so clear and helpful. Thank you very much. I have hot water again!

[@blizteredthumbs7911]

Excellent video. 1000 thank you's for the knowledge pass on 👌

[@brandonlawther3731]

Hi I am having an issue where the reset button on the thermostat is popping every couple of weeks we have changed the thermostat twice and the immersion twice but still having this issue. We have tested the cable from the fuse board, and the flex going to the thermostat and all is fine however we are still having this issue, is there something more than an electrical issue causing it to trip every couple weeks?

[@jwflame]

The only electrical issue which could cause that is if the flex/cable has overheated in the past and the ends of the wires connected to the thermostat have softened and won't make proper contact with it. That will cause a poor connection which will overheat the thermostats terminals. The fix is to replace the cable between the wall switch and the heater. The other possibility is that there is another heat source for the hot water cylinder which is heating the water to an excessive level. Common where a solid fuel boiler / woodburner or similar is connected to it but can happen with gas/oil where the flow temperature is set far too high.

[@WoodWedgie]

I have seen nuisance tripping on the overheat when the immersion heater is covered by towels drying in an airing cupboard. Thermal solar tripping the immersion when the transfer pipes were not insulated, heating the airing cupboard to a high temperature.

[@nisarhussain9840]

Great, you've explained it very well. Appreciation. Well done

[@asdreww]

Many thanks John, your videos are excellent.

[@emf3652]

Thanks, great presentation. Lots of valuable info.

[@1337Shockwav3]

Are you a teacher or something? It's incredible how you raise the volume of your voice with certain buzzwords.

[@biddlelove2135]

Get ya pants down boy!

[@christopherfearns99]

Hi John, great video helped me out today 👍

[@davebull9600]

Brilliant video, I will go check my mums immersion heater right now

[@ph54kah]

Great video, good info thanks. And I like the multi meter, not seen one of thought since they took mine away and replaced it with something that doesn't work.

[@JesusIsLord-]

Thank you for the video. I have a hot water tank with 2 elements. I don't know whether the water is hot or cold. Is there a way to get the temperature of the heating element please?

[@nsoper19]

I've got one of these on my tank as a backup. Gas boiler most of the time but also an immersion heater in case gas fails or the boiler conks out.

[@jeremylister89]

Questions on the fluke high voltage tester: can it do 3kv? Also do you know if it ramps up to the high voltage, effectively a soft start. For production testing this may be set to a second ramp and ramp down times. Reason: if testing electronic PSU, hitting the equipment with a fast edge can cause an internal resonance leading to a much higher voltage = breakdown/damage risk.

[@pnmbmw]

What a great voice.

[@lynner9427]

We are now flying at 35,000 feet and the temperature at our destination is a chilly 13c......... David Gunson stylee ;)

[@dlewis129]

Thank you John. Excellent as ever.

[@ia4387]

Hi John, great video here. A little off topic now but if a three phase motor draws 60 amps for example, does 60 amps flow in each phase or is it divided between the three phases i.e. 20 amps in each phase? Thanks

[@stephenhedge2489]

A great help - thank you. My heater element is screwed in at the BOTTOM of my tank so in order to save draining the whole thing, I am hoping to disconnect the power & test the element, thermostat and earth IN SITU without removing the whole element. IS THIS OK?

[@jwflame]

Yes,. Isolate, disconnect all of the wires from the element and then test.

[@daneclements19]

Hi jw great vid .my emersion unit has stopped working . I've just tested my temp unit (with draper analogue multimeter ) and it clicks off at the lowest temp setting (5 degree) it also doesn't have a reset switch.would you say this is a faulty unit . Cheers Dane

[@eurotropia]

You are the best! Very professional! Totally fav!

[@RODALCO2007]

Great video. Very informative. Thanks for showing.

[@HoudalothAli]

For demonstration this video is good, but in reality we do the testing whilst it's still attached to the hotwater cylinder and after we have switched off the MCB to it and also the switch connected to it. Sadly with such tight space in an airing cupboard, it can be difficult.

[@AnthonyFrancisJones]

Excellent! Just what I needed to know. Thanks. My Eddi unit is heating the water too much and so the thermostat needs looking at!

[@carolreid9755]

Thank you for this. I had a new immersion heater fitted and after a week it stopped, the plumber told me to reset the button and I watched your video. I have left a message for him as I am reset it every day. He now says to turn down the thermostat. So now I am turning down the temperature every day by one mark and reset the heater. There are no numbers on the thermostat so I have no idea what I am setting it to. Are the numbers or your demo standard and is there a temperature I should not go below ? Many thanks if you are this for any reply.

[@jwflame]

Although they have numbers on them, they should be set to 60-65C and left there. New ones are usually set like that from the factory, and don't require any adjustment. If you have to reset the thing every day, the thermostat has failed and needs to be replaced.

[@eazyrat]

Thanks. I tried these tests got 50 ohms on one reading. The problem for me wasn't that the heater wasn't working but the reset kept activating. The water did seem very hot. Broken stat?

[@rogphillips08]

An excellent and most informative video. Thank you.

[@kathryngreen1351]

Excellent explanation. Helped me identify and resolve a problem with my immersion. Thank you

[@AndreasLeon82]

How did thermostat opened its contact at 50 C ? what is the temperature in your test room???

[@bobbyblanco1118]

Hi john. Don't know if this is a silly question or not. But if the element is in the cylinder, sitting in the water, would it still be alright to do the insulation resistance test at 200 volts or 500 volts? I'm thinking safety passing voltage around the earths in the house if the element has broke down inside?

[@jwflame]

+robert brennan Yes, totally safe. The 500V from the tester only exists between the two test leads, the only way anyone or any thing could be exposed to the 500V is if they were in contact with both test leads at the same time.