Central Heating and towel rails

[Channel Hopper]

I've got one in the bathroom that runs off the heating side of the boiler, however in a friends house, their towel rail is fed from the hot water side of things. So after running a bath, the rail is hot and the towels heated.
Downside though, if you are sitting on the toilet then the room remains cold.

Additionally I would have thought a series connection for the hot water to the bath would lower the pressure for a shower attachment.

Is there a specific standard method of fitting of these things ?

 

[sonnetpete]

CH, sadly 'Bob the Builder' who is doing my renovations is not back from the UK until Monday, otherwise I could have asked him, as he is a qualified heating engineer. If you haven't a definitive answer by then I'll see if he can suggest anything.

The towel rail in my bathroom is taken off the central heating system supplied by the Rayburn in the kitchen. Obviously it isn't heated in the summer and I have a free standing electric towel rail as a back up. I could have asked him to run the towel rail in series with the hot water/shower supply. I guess it depends on what your water pressure is like. Here it's very high as we are at the bottom of a hill.

 

[PaulR]

They normally run in the central heating circuit. If you have thermostatic valves on all your radiators then the towel rail is your "safety valve" to prevent pressure build-up if all the thermo valves were to close together. In fact if you don't have a towel rail then one of the radiators is supposed to be unregulated. This radiator is usually in the bathroom in this case.

In your friend's house, does he have thermo valves on his radiators? If so, where is his unregulated flow through?

And I agree about the shower!

 

[Topper]

Well in my bathroom I have had for 23 years a heated towel rail which works off the copper coil hot water supply that heats up the hot water tank, the radiator in the bathroom has thermostatic valve and the whole lot is fed by the central heating boiler. The boiler output is regulated by the demand valve that is requesting either central heating, hot water or both. There are no pressure problems as the hot water supply from the taps is completely separate to the supply feeding the heating coil in the tank. When we bought the house, the hot water cylinder was of the diaphragm type which was fed from the central heating boiler resulting in brown baths hence the new cylinder.

 

[Channel Hopper]

Thanks, since the HW and CH are separate outputs in the boiler (goverened by a demand diaphram) the towel rail should not normally get hot if the CH only is on, but it does.

So I will probably have to investigate further on this

 

[pgh13]

I wouldn't have thought it was a good idea (or even if the regs permit it). The towel rails I've come across have been made of steel so will corrode internally contaminating the water

 

[PaulR]

Good point. If the towel rail is part of the heating circuit then it will be protected by the inhibitor that should be added to the water. In the case that CH is talking about that's not possible.

Topper, yours is slightly different to CH's as yours is on the heating circuit itself. This surely means that the rail only gets hot when the reservoir is being heated up which is not necessarily the same as when a bath is drawn? It does mean that it would be protected by inhibitor though.

 

[Topper]

Topper, yours is slightly different to CH's as yours is on the heating circuit itself. This surely means that the rail only gets hot when the reservoir is being heated up which is not necessarily the same as when a bath is drawn? It does mean that it would be protected by inhibitor though.

Mmmm not sure I understand Paul, the demand valve is on top of the boiler and directs the boiler output as mentioned. I am not in the habit of drawing cold baths hence when filling the bath I would be drawing water from the hot water tank which then re-fills with cold water tripping the thermostat and demand valve to redirect to central coil to heat the water again.

Surely CH's demand diaphram is only the equivalent of a demand valve and the demand diaphram is leaking a tad allowing convection to heat the rail when the central heating is on?

Arn't all radiators and towel rails made of steel? Unless cast iron antiquities of course

 

[Channel Hopper]

Hmmm. Demand diaphragms.

I was asked to replace the diverter diaphragm a few months ago as the hot water was failing to come on but the demand one remains as it was when the boiler was fitted. Maybe that is also coming close to perishing.

Without taking up tiles in the bathroom though, I do not know where the pipes go.

Additionally the towel rail looks like stainless steel rather than steel and chrome (definitely not cast iron though).

 

[PaulR]

not sure I understand Paul

Your rail is heated by the water (in a closed circuit) that the boiler sends to the heating coil inside the reservoir. If I've understood correctly, the one CH is talking about is fed by the water leaving the reservoir to fill the bath. This is an open circuit.

Hmmm. Demand diaphragms.

Doing your Homer Simpson impression now, CH?