Follow-up to Heated(electric)Towel Rail

[T]

Hi. What should i use to fill a non-plumbed towel rail. I realised that nearly all plumbed in towel rails can have a electric heater element fitted inside, this is so the towel rail can be used when the central heating is not being used (summer). What i was going to do because to plumb in the towel rail would be too differcult (locacation) was just to use the electric element on a fused switch when required, the thing is i'm not sure what to fill the rail with, normal water, distilled or something else? Is this idea possible, has anyone else done this? Cheers T

[Chris J Dixon]

One possible snag with your plan is that there is no provision to cope with expansion of the fluid, unless you leave a deliberate air space, which would mean that the top of the radiator would be cold. Not sure how it would be for corrosion either.

Chris

[ARWadsworth]

How much expansion do you expect from a two hundred watt heater in a towel radiator? The pressure in a combi central heating system may rise up to 3 bar when hot and most rads will take much more before leaking. I have seen plumbers presure test up to 5 bar when they commissioning systems. As for corrosion then use central heating inhibitor in the radiator as I pointed out on the OPs first post asking the same question.

Adam

[T]

Thanks, I was thinking of leaving approx 2cm gap inside for any expansion, plus what about adding a mixture of 25% of anti-freeze to 75% of distilled water? Comments please. T

[Andrew Gabriel]

You could just leave the bleed nipple open, like a tiny vented system, although you'll have to change the inhibitor every few years (just like a vented system too).

Central heating inhibitor with antifreeze is available, if you think there's a risk of freezing, e.g. Sentinel X500