Does this immersion heater have a safety cutoff?

[Vicario]

I've had this since about 2018 and have never thought to check if it has a cutoff which prevents the water from boiling if there's a fault. I have googled but there are several models and I'm a bit confused. Can anyone help? Many thanks.

 

[avonmouth]

The round white button shape has a screwdriver slot for adjusting the temp.

 

[bernardgreen]

Looks like it does have a safety cut out

Manual Button Cut Out 13115 Rated at 85°C

Manual Button Cut Out Rated at 85°C Part No 13115 For use in Backersafe VS Range of Immersion Heaters

www.backer.co.uk

 

[ericmark]

It does not seem to be built into the thermostat but alongside it

 

[Harry Bloomfield]

it

The more recent BT18 thermostats, include the cutout. Your photo suggests you have a separate cutout, as zoomed into by Eric, but I think I might be able to see a cutout built into the main thermostat - see the tiny, recessed white button, next to the larger, white temperature adjustment.

Perhaps the thermostat has been replaced by a later version?

 

[polesapart]

EDIT Post withdrawn; incorrect info.

 

[Harry Bloomfield]

The BackerBM18 has no safety cutout, the BMST 18 does.

This suggests otherwise - a none resettable cutout - https://www.internet-electrical.co....over-temperature-cut-out-15a-length-18-inches

 

[polesapart]

Yep, looks like I got that wrong.

I've edited/withdrawn my post.

 

[Harry Bloomfield]

Yep, looks like I got that wrong.

I've edited/withdrawn my post.

It is still odd, why there is both a resettable, and a none-resettable cutout installed.

 

[Johntheo5]

I have seen both, the older type were just a control stat with a (the) separate o/temp stat attached as shown and wired in series with the control stat, if the o/temp stat operated on the one I saw, then the immersion cover had to be removed to reset it. The more modern type have a combined control & o/temp stat(s) and there is a reset push button in the immersion cover top.

 

[Vicario]

So will mine still cut off the supply if the water gets too hot (boils?), but then can't be used again and will need to be replaced? How much water needs to be drained from the cylinder in order to replace it? I have tested the gate valve where the cold water comes down from the loft and that still works so I can cut the feed to the cylinder. The drain valve at the bottom looks a bit iffy though, so I'll probably leave the job to a professional.

 

[Harry Bloomfield]

So will mine still cut off the supply if the water gets too hot (boils?), but then can't be used again and will need to be replaced?

You have two safety systems on that, to prevent it boiling. One with the two white wires, which is resettable, then one built into the thermostat. The latter, should it trip, is not resettable, you would need to replace it, should it trip.

How much water needs to be drained from the cylinder in order to replace it?

None at all. The thermostat simply pulls out of a 'pocket', like a sealed tube.