DIYnot
Local | Network
   DIYnot > Forums
Local | Network
DIYnot Network Local DIYnot Network Local  
  Forum IndexForum Index     RulesRules    HelpHelp     Join FREERegister Free     About CookiesCookies     SearchSearch     LoginLogin 

immersion heater safety cutout problems


 
Post new topic   Reply to topic    DIYnot.com Forum Index > Electrics UK
Search this topic :: View previous topic :: View next topic  
Author Message
tracey2109

from United Kingdom

Joined: 31 Dec 2009
Posts: 2
Location: Cornwall,
United Kingdom

PostPosted: Thu Dec 31, 2009 9:55 am Reply with quote

Hi, I'm really sorry if this has been asked before - have had a look and couldn't find it.

We have an immersion heater that we use when we are not using our coal fire to heat our water (we don't have central heating). However we had to have the element replaced and since then we have been having problems. We've found out that this is due to the new safety cutout required by law and the fact that our coal fire must over heat the water causing the immersion heater to trip even when it is not on. We can reset the immersion heater each time but were wondering if there is any way we could avoid this as it is not really the most ideal thing.

Thanks very much for any help,

Tracey icon_smile.gif
Back to top
 Alert Moderators

If you do not want to see this advert, click here to login or if you are new click here to join free.
BS3036

from United Kingdom

Joined: 24 Sep 2007
Posts: 666
Location: United Kingdom
Thanked: 19 times

PostPosted: Thu Dec 31, 2009 10:15 am Reply with quote

The cutout is often built into the thermostat which is a replaceable item. I believe that thermostats are still available without the safety cutout because they are still required in situations where the cutout is not appropriate.

In a case like yours, where you can already heat the water to higher temperatures than the cutout wants, it would seem logical to use one of these, especially as you have already been doing this for years.

I am however, not an expert, and there is of course a potential risk involved which this cutout is supposed to reduce.
Back to top
 Alert Moderators
ColJack

from United Kingdom

Joined: 16 Feb 2007
Posts: 11773
Location: West Midlands,
United Kingdom
Thanked: 408 times

PostPosted: Thu Dec 31, 2009 11:51 am Reply with quote

do you have a header tank for it? is is in the loft perhaps?

you have to have the cutout in these things to stop what happened to that little girl..
the water boiled and back fed to the loft tank and overflowed, scalding her in her bed..
Back to top
 Alert Moderators
BS3036

from United Kingdom

Joined: 24 Sep 2007
Posts: 666
Location: United Kingdom
Thanked: 19 times

PostPosted: Thu Dec 31, 2009 2:55 pm Reply with quote

That's quite true, Col. Unfortunately, in this case, the cutout won't stop the coal fire from doing exactly the same. I guess you'd need a zone valve to divert the excess heat to a heat dump. Not traditional equipment though.

I wonder if a different forum might better qualified to make suggestions about heating systems?
Back to top
 Alert Moderators
Steve

from United Kingdom

Joined: 15 Apr 2005
Posts: 15902
Location: Yorkshire,
United Kingdom
Thanked: 220 times

PostPosted: Thu Dec 31, 2009 6:10 pm Reply with quote

A metal tank. Wont melt if the boiling water gets in it. Still not good though.
Back to top
 Alert Moderators
RF Lighting

from United Kingdom

Joined: 31 Mar 2006
Posts: 17228
Location: Leeds,
United Kingdom
Thanked: 894 times

PostPosted: Thu Dec 31, 2009 7:46 pm Reply with quote

Like Steve says, providing the header tank is metal, then an over temperature cut out is not required.

If the header tank is plastic unfortunatly the cutout is required, and I'd also be a bit concerned about the safety of a system that could heat the water so hot and discharge it into a plastic header tank, but I'm no plumbing expert.
Back to top
 Alert Moderators
tracey2109

from United Kingdom

Joined: 31 Dec 2009
Posts: 2
Location: Cornwall,
United Kingdom

PostPosted: Wed Jan 06, 2010 11:11 pm Reply with quote

hi, thanks for all your help. we don't have the worries about the tank as we are in a bungalow so the tank is in our bathroom and is metal. mum says also that our overflow goes outside and not into our cold water tank to prevent spare hot getting in there.
Back to top
 Alert Moderators
flameport

from United Kingdom

Joined: 10 Mar 2007
Posts: 4009
Location: Bournemouth,
United Kingdom
Thanked: 630 times

PostPosted: Thu Jan 07, 2010 12:29 am Reply with quote

If your coal boiler is heating the hot water to a temperature which causes the immersion heater cutout to operate, there is something very wrong with the system.
At the very least, there should be somewhere for the excess heat to go - usually a suitably sized radiator in the bathroom which cannot be turned off.

Although your header tank may be metal, this does not mean it is safe.
Metal tanks (particularly old ones) can fail. So can hot water cylinders.
You don't want boiling water coming out of your taps - it will cause serious injury to someone.
Overflowing outside is no good either - what if the boiling water overflowed as someone was walking past?

This is not an electrical problem.
You need to get the whole system checked by a heating engineer familiar with solid fuel/gravity hot water systems.
Back to top
 Alert Moderators
Search this topic :: View previous topic :: View next topic  
Post new topic   Reply to topic    DIYnot.com Forum Index > Electrics UK All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Similar Topics   Replies   Views   Posted 
help identify service head and cutout or isolator switch 7 320 Tue Apr 26, 2011 11:13 pm
Type of fuse within cutout 8 840 Fri Apr 09, 2010 4:42 pm
What is the quickest way to get the cutout re-installed? 20 1000 Mon Oct 19, 2009 7:49 pm
Cutout 36 1140 Tue Jun 05, 2012 6:30 pm
Leaking sealant around cutout 36 600 Sat Aug 04, 2012 6:16 pm


 
DIYnot
Find an Expert | Find a Supplier | Search DIYnot.com
Network | Advertising | Newsletter
DIY | DIY How To | @home | DIY Wiki | DIY Forum
By using this site you agree to our Terms of Service / Disclaimer.
Please read our Privacy Policy. Copyright © 2000-2014 DIYnot Limited.