Electric Towel Rail not heating up

[deco100]

Hi,

I have a towel rail radiator which we use with the normal central heating in the colder months and it has an electric element in it which we use in the summer. It hasn't worked this summer at all...so how do I know if

- the fuse has blown
- the element has died

?

Thanks in advance

d

 

[Spark123]

Get your multimeter out, set it to ohms range and measure the resistance across the fuse - should be approx zero ohms.
Measure the resistance of the element, should be a few ohms (could be tens of ohms) but not infinity. If it is infinity then the element has gone.
If there is a thermostat you can also measure the resistance across that, with it cold it should be approx zero ohms.

 

[deco100]

Thanks Spark123. I'll try it using the fuse measurement. But as a matter of interest, how do I measure the resistance across the element - can I do it without removing the element and draining the radiator?

d

 

[ban-all-sheds]

Yes - draining the rad and removing the element isn't necessary, you just need to get at the L & N terminals of it, maybe directly if something plugs into the end of it, or at the end of the cable coming from it if it has a captive lead.

 

[ban-all-sheds]

BTW - have you found that you need to bleed that rad frequently?

 

[RF Lighting]

We've got a summer element in our bathroom rad.

Never had to bleed it. (open vented system)

 

[deco100]

BTW - have you found that you need to bleed that rad frequently?

No, not at all, maybe did it once in a couple of years.

Is it OK to bleed them like a normal radiator if this means there's no room for expansion?

 

[flameport]

Is it OK to bleed them like a normal radiator if this means there's no room for expansion?

The expansion space is provided by the rest of the heating system - although turned off at one valve, the other one will still be open and connected to the other rads, and therefore to the expansion vessel (or header tank on older systems)

 

[TicklyT]

If the heating element is a couple of hundred watts, the resistance would be of the order of 200 to 300 Ohms. If it's about 500 Watts, it would be around 100 - 150 Ohms.

A resistance between 15 and 20 Ohms would be more appropriate for a 3KW immersion heater.

IME there's usually one radiator on a system that needs bleeding more than the others. that's probably just down to a quirk of the individual system layout, with any air / gases always collecting at the same point.
If the system is in good order, the need for any bleeding is minimal.

 

[ban-all-sheds]

Often the highest point in the system is the bathroom towel rail.

I asked about the bleeding because a few years ago I lost an element because I didn't keep on top of that (a clean and fresh inhibitor seems to have done the trick now) - I let it get too low for too long, and half the element was not in water, which probably did it no good at all.