Immersion Heater trips out my RCD

[mac1_8]

Hi Folks

New to this site but it looks full of info. At the weekend my RCD tripped out knocking out all my sockets in the house. I isolated it down to my Immersion heater. Does this mean i have to change the element/thermostat? Is this something a plumbing dummy can do?

Also the other week my toilet suddenly decided to pack up. Managed to take the cistern apart and change the syphon ok. put it all back together but it leaks slightly out the bottom of the cistern where it is screwed together when it is flushed. Not loads of water but enough to become annoying. When i took it all off the first time around there was a rubber ring around the toilet bowl that sat underneath the cistern. Have i broken the seal or something that it had before? Do i need to get another one of these rings or something else??

cheers.

M

 

[murdock]

The seal you are talking about is called a donut fitting and is always worth replacing when you change the syphon even if it looks o.k. They cost about £1. As for your cylinder immersion heater stat its simple just remove the wire and the stat will just pull out on a long rod no need to drain your cylinder as this sits inside your emersion heater get a replacement the same length. If this does not work you will need to replace your immersion heater and these can be a nightmare to get off so get a plumber dont do it yourself or you will have problems.

 

[joe-90]

I think you'll find the element is shorting to earth. It's a common problem.


joe

 

[mac1_8]

Cheers, thats a great help. Sounds just the advice i was looking for. Am i able to buy one of these 'donut' rings online, i remember looking at the time on plumbworld/screwfix but couldn't find it. Any other websites? Would i need any sealant too to make sure?

With regards to the heater, ami able to find out whether it is the thermostat or the actual element that has gone without going out and buying a new one through trial and error.

cheers again.

M

 

[mac1_8]

Thats to do with the wires touching isn't it?? What do i do just move them out of the way?

M

 

[oilman]

With regards to the heater, ami able to find out whether it is the thermostat or the actual element that has gone without going out and buying a new one through trial and error.

cheers again.

M

Joe-90 has said what it is, and it IS a common problem. Buy an element and a stat, because they have both had a life, now one's dead and the other is not far behind.

 

[joe-90]

I've never known a thermostat to cause the problem. What ususally happens is the element breaks and the broken bit touches the casing and trips out.



joe

 

[mac1_8]

Great cheers joe-90. I've heard that to replace an immersion element you have to drain the water off etc... is this right? Or is it something a complete novice can do. This is my first house ya see and with it comes these problems.

M

 

[joe-90]

You'll have to drain it somwhat, but first of all you need a big spanner from B&Q to see if you get the thing loosened. They sometimes get really tight and you won't be able to shift it without collapsing the tank. If you can't feel it loosen - get a plumber in. He'll know a trick or two.


joe

 

[oilman]

I've never drained anything off a tank, turn off the stopcocks, open a hot tap, put some rag or a towel round the heater amd it will catch the small amount of water that comes out. Hitting the spanner with a hammer helps.

 

[murdock]

You will get a donut fitting in with a coupling kit screwfix kat part number 17405 £1.79 they also sell them at B&Q.

 

[meldrew's_mate]

Mac1_8, all good advice except that a thermostat cannot and will not trip an RCD (Joe has said this already). You will be surprised just how corroded and split your old heater will be!

Most top mounted heaters are 27" to 30", side mounted about 12" I strongly suggest you spend just a couple of pounds extra for the corrosion resistant type, often called incalloy, they last a lot longer in hard water areas.

IF you have a top mounted imm. htr. you will lose about 2 litres if you turn off the cold water feed valve (usually near the top of the cylinder, feeds into the bottom of the cylinder where it usually has a drain point), so have enough towels etc to catch it. IMO it is better to drain a couple of gallons from the drain cock, then you have time to do the job even if the cold feed valve does not hold perfectly.

In additon I recommend you get a "box" type immersion heater spanner with a tommy bar handle, this way you use the handle to push and pull at the same time, producing lots of rotating force rather than side force if you use a single handled spanner.

And finally, don't start it Sunday afternoon, all the plumbing suppliers usually shut at noon Saturday, and most plumbers are in Church on Sundays (which is why most smell of Communion Wine (or similar) in the afternoon.

The option we haven't covered is that of a bottom (side) mounted immersion heater - if that is what you have you MUST fully drain the cylinder to avoid getting very wet

 

[Agile]

"""And finally, don't start it Sunday afternoon, most plumbers are in Church on Sundays. """

I know that its sacriligious but my first thought on reading that posting is that the plumbers are in Church asking forgiveness for their sins in ripping off old folk during the previous week.

Please understand that it is only a joke and I have had half a bottle of Dumisani this evening. Most plumbers are very nice and reasonable people. For example I stopped by to turn on a rad lockshield for this old fellow today, only 10 min, and he nicely asked if he owed me anything, "of course not" !

Tony Glazier

 

[Softus]

mac_1_8

You've had wise words from everyone who's posted on this one, but I'd add two things:

1. To answer your question about sealant, if you re-use the old donut then use some good quality silicone sealant - if you do this then pay very careful attention to the orientation of the donut as you take if off, and put it back the same way. Re-use can can be an advantage on close-coupled systems so that you're unlikely to need to redrill the cistern mounting holes - this can arise if the new donut that you fit is fatter.

If you choose to replace the donut, do your best to get one of the same shape - they're not all the same, and the one that originally came with your WC was the one designed to fit it. And don't use sealant on the new one.

2. Just in case you live in a hard water area, you need to know that you get an Incaloy IH element - it makes ecomomic sense to use these as they last significantly longer (which is why some plumbers don't like them).

While we're on the subject of IH thermostats, and while I'm feeling too lazy to look it up, does anyone know the current regulations regarding resettable thermostats?

 

[Agile]

Interestingly, its illegal to MANUFACTURE non manually resettable stats but NOT illegal to sell or fit them.

That was a good decision as it enables old stock to be used up and stops anyone having to throw old ones away and lose the value.

Having said that, since all professionals will know that they are expected to be fitted now as suppliers have been selling the new ones for some time, it would be unwise for a professional to fit an old type.

The old ones will continue to be sold ( and bought ) at car boot sales across the country for many years to come.

Tony