Immersion heater thermostat issue..

[AL_z]

In the loft in my newly acquired house, is an immersion heater with an integral header tank. The heater element is at the base of the cylinder, and the visible part of it (where the cable is attached) has a thermostat, which can be turned with a screwdriver. I've been trying to get the water temperature down to something comfortable, but the thermostat doesn't seem to be working. I turned it down, yet the water still seems way too hot. It must reach near boiling point, which can't be much good for my plastic plumbing! Is the thermostat likely to be broken or stuck? Or is it possible that it's not connected up properly, somehow? Is this a common fault and is there a known easy cure?

Incidentally, there appears to be a second thermostat, about 12" above the base of the cylinder. It appears to have three terminals for a cable, yet no cable is attached. Can anyone clarify what that is all about?

Many thanks,

Al

[Bob Minchin]

You have what I know as a 'Fortic' tank - possibly the first manufacturer of such things.

Usually there are two immersion heaters, the top one just heats a small amount of water and the lower one is used to heat the whole tank, There would be aswitch to select one or the other but not both. Sometimes only one is used which sounds like the system you have.

Thermostats do fail and tis is why new ones have an over heat trip.

All you need to do is replace the thermostat. Take out the old one and check the length, then order the right one here.

[Heliotrope Smith]

"AL_z" wrote in news:Xns9DE2C31A0C671zzzzzz@130.133.4.11:

I would suspect that that your cylinder is being heated by your boiler as well as/instead of the electric immersion.

Are there flow and return coming out of the side of the cylinder? Are these hot?

You may well have a gravity primary flow to the cylinder relying on the boiler thermostat to regulate the heat to the primaries.

A bit more information on your heating system (if any) would help.

What boiler, programmer/time clock. Whether any motorised valves, pump etc.

--- news://freenews.netfront.net/ - complaints: [e-mail] ---

[Peter Andrews]

Also note that to turn a thermostat down you often have to turn the screw clockwise!! Are you sure that you turned it according to the markings - torch and good eyesight needed.

Peter

[Tabby]

Probably your thermostat is stuck shut. There are other possibilities, but that's msot likely. If you do have a 2nd stat, you could simply connect that up in place and see if problem solved.

NT

[AL_z]

Bob Minchin wrote in news:Bddeo.81227$Pa3.13764@hurricane:

Hi Bob, Thanks - that sounds easy! This may be a daft question, but do I need to drain the cylinder before removing the thermostat?

Al

[AL_z]

Heliotrope Smith wrote in news:Xns9DE2CFC6565CFsmithheliotropemoc@202.177.16.121:

Hi, I don't have a boiler, or central heating. The immersion heater is the only water heater in the house. I use it solely to feed the hot taps and a shower.

Al

[AL_z]

"Peter Andrews" wrote in news:56oeo.31137$Vh3.24279@hurricane:

Hi Peter, Thanks. Yes, I knew about this, and I was turning it in the correct direction (clockwise = cooler).

Al

[Tim Watts]

Yes.

[AL_z]

Tabby wrote in news:453865cc-3d01-445b-a071- [e-mail]:

Thanks, can you give me some guidance on how to do this? The 2nd stat is located about 12" away from the heater element, which has its own stat incorporated. The 2nd stat appears to have no heater element of its own. So if I simply remove the cable from the main heater+stat, and connect it to the 2nds stat, there will be no juice going to the heating element. So perhaps I need to connect the 2nd stat it *in parallel* to the main heating element?

Al

[ARWadsworth]

Are you sure about that? I swapped a thermostat on Friday without draining the cylinder.

Adam

[Peter Watson]

Really?

Heater element yes, but thermostat?

I'm sure last time I looked that the thermostat goes into a sleeve in the element assembly and can be simply withdrawn and replaced...

[Mike Clarke]

NO - unless you want a big flash and bang!

It would need to be connected in series but don't do this unless you REALLY know what you're doing.

[Tim Watts]

Oh, sorry - thermostats are usually in a metal tube which holds the water back and easily swapped. I transposed that to "swap heater" for some reason due to lack of coffee :(

[Dave Baker]

As you've already been told the second stat will be for controlling a central heating system and is nothing to do with your current problem. Leave it alone and get a replacement stat for the immersion heater.

[AL_z]

harry wrote in news: [e-mail]:

Thanks for the input. I've never had the running-out-of-water problem. Ther is always ample hot water to fill a bath. Good point about losing the heat into the loft. I'd move the thing into the top floor of the house, but I fear it would then not give enough output pressure to run my shower, which comes directly from the immersion heater, with no pump, etc. Money is short at present, so I'll probably put up with this device until I can afford a combi boiler, or similar.

Al

[AL_z]

Mike Clarke wrote in news: [e-mail]:

Only on November 5th ;-)

Al