Immersion heaters are a pain in the rear.

[Millsy 82]

I've got a problem with immersion heaters just keep randomly tripping even though they work perfectly 99% of the time and even on brand new immersions that I have left to heat up and checked the temperature.

They keep going on the thermal cutouts which are built in, I swear they are just not fit for the job and it makes you look like an idiot going back to reset them.

 

[Best]

Some people hang clothes over the heaters covers & the cut out gets too much heat & cuts off power.
Thats why some heater covers have the words Do not cover, stamped in them.
Also might overheat if another source is heating cylinder.

 

[Millsy 82]

What are they meant to cut out at? Most of my cylinders I set to 55-60 and they still trip.

Good point about hanging clothes over them.

 

[Best]

What are they meant to cut out at? Most of my cylinders I set to 55-60 and they still trip.

Good point about hanging clothes over them.

Tbh, I am not sure. Without looking it up, I assume they cut out at close to boiling point, but really could do with cutting off at much lower temperature. Edit, - just read that they cut out at 95 or 98 degrees.
The heat builds up inside the heater cover. I had it happen with the white thermostats & I had to lower the max setting on the stat to 55. Maybe you need to try a different brand.
Getting off the point a bit, just wondered do you ever see Willis external heaters? Think they are largely mostly fitted in this part of the UK.

 

[townfanjon]

Millsy are these unvented cyl immersions ? What make are they ?

 

[Millsy 82]

1 unvented on a megaflo. 2 vented different brands. Whatever plumb center and Williams sell.

All I do is go and reset and drop the temperature a little bit but on the megaflo they have said the water isn't got enough and it's set on about 3 and still tripped again.

 

[Millsy 82]

Never heard of a willis external heater.

 

[Best]

Never heard of a willis external heater.

Willis Renewables - Solasyphon - How it works
It is basically just a small copper cylinder (about 350mm long & diamater about 80mm) with a standard 11" immersion element with stat. It just puts the heated water to the top of the vented cylinder & heats downwards if needed. Very quick & 2 minutes gives you very hot water for a shave.

 

[townfanjon]

I haven't a clue what stats are going in mega flows these days , you are right they are a pain , the closer the two temps are the worse the problem is , but this sounds like it's the high limit stat rather than the control stat. When you say they are built in , are they the type that have 'flats' on , and look like they come out with a spanner, because it might be worth trying changing them rather than an expensive drain down and a new immersion heater

 

[Millsy 82]

Can anyone recommend a reliable immersion heater as I have 1 gone down yet again! So I went out and missed the first 10 minutes of the rugby (shame it wasn't all of it) and now the customer is saying the water isn't hot enough after resetting and it's been 3 hours!

 

[Ray Stafford]

I may be wrong, but I think they are pretty much all made by Backer or Thermotec, regardless of what it says on the label.

 

[townfanjon]

Milsey are you sure it's the immersion and not a either stat .

 

[Millsy 82]

Sorry it's the stats keep tripping. But I can't keep going on every 6 weeks going back and resetting them! If they are new they should work! Simple as that really isn't it.

 

[Millsy 82]

I may be wrong, but I think they are pretty much all made by Backer or Thermotec, regardless of what it says on the label.

It's a backer in there now.

 

[townfanjon]

Cheppo immersion heater stats are bloody useless, believe you me I have had no end of trouble with them , the backers are alright ish, I have loads of trouble with cotherms, it's all because they are cheap, why a manufacturer doesn't make a decent quality stat and charge accordingly I will never know.
Unless somebody can tell you / me otherwise the only decent one made was the sunvic vk range not vkl, think I have got that the right way round.

 

[mfgs]

I had the same issue a while back, it turned out to be ambient heat in the airing cupboard causing it due to too many clothes and a lack of ventilation. Ask you customer to leave the airing cupboard door slightly open and remove any clothes/towels etc which are very close above the cylinder to prove this.

 

[Millsy 82]

Credit where it's due I've just phoned backer technical and they said they will send a new stat out.

 

[Millsy 82]

Credit where it's due I've just phoned backer technical and they said they will send a new stat out.

 

[townfanjon]

Lol, don't hold your breath pal, I have swapped two today , I fitted them this time last year .