Control of towel rail/radiator temperature

[merkland]

We have a towel rail/radiator in our bathroom which is heated directly by our Aga cooker on the same circuit as the hot water cylinder. Our problem is that this radiator is always so hot that it will burn bare skin. We have lived with this problem for years so are on our guard but we now have young grandchildren on the scene so feel we need to do something about it. I called in our plumber to see if some kind of thermostat could be fitted to keep the rail at a safe temperature only to be told that thermostats only switch radiators on or off according to desired room temperature and do not control the actual temperature of the radiator. He  could only suggest we kept the rail covered up or try running the Aga at a lower setting. Running the Aga at a lower setting than it is currently is not an option as the temperature of the Aga would then be to low for cooking. This problem stems from listening to the so called experts when installing the Aga new as they said it would need the big boiler(135 gallons per day) rather than the standard(90 gallons per day) in order to able to cope with the extra load of the towel rail. They were completely wrong as subsequently we have had to run the cooker at it's lowest possible setting to avoid the water constantly boiling!
My question is does anyone know if there is a way of controlling a radiator's temperature?

Merkland.

[tony.]

Merkland

What about one of these.
https://supreme1.sslpowered.com/cgi-bin/DMdatabase.cgi?action=/mnt/w0113/d01/s11/b009fa92/cgi-bin/home/Shop/Radiator_Valves/Myson_Radiator_Valves.txt&item=00006

The capillary end could be glues to the towel rail, and would give feedback to the trv, a bit of tweeking and im sure it would work.

Regards

Tony

[dhaslam]

Restricting the flow throw the towel rail should  drop the temperature.    I suppose a  mixer valve  as used for DHW would do  the job better.     

[merkland]

Tony,

Thank you for your suggestion it looks as if it might be worth trying. I think I might visit our local plumbing supplies firm to see if I can see one in the flesh(so to speak) so that I may work out how to fit one to the towel rail. In the meantime I have sent an email to Myson asking for their view or whether they have any other suggestions(I wonder if they will reply!).

dhaslam,

Thank you for your suggestion however I don't think it would suit as using a mixer valve would require additional plumbing to provide a cold water supply for blending to reduce the temperature, it would not be practical to be continually feeding additional water into the hot water system - if nothing else the header tank overflow would be running continuously!
Restricting the flow through the towel rail should work in theory but how to achieve any practical and repeatable method of control is the 64 thousand dollar question!

merkland.

[Countrypaul]

Is the towel rail needed to dissapate heat, or just for convenience? The reason I ask is that surely the water coming out of the towel rail is cooler than that going in, if you just want to keep the towel rail hot (but not scolding) surely you could mix the cooler output water with the hot water from the Aga using the TMV dhaslam suggests, teh remainer of the cooler water going where it does now.

[A.L.]

hi,

I am not sure the remote sensing TRV will work, the data sheet,

http://www.myson.co.uk/img/TRV_Remote_Sensor_Sept_2009.pdf

suggests that the TRV will be fully shut at any temperaure above 28C and remember  when the TRV is open water at the radiator entry

point will still be at its original temperature and therefore so will the radiator, at least near the entry point.

I think you need a low surface temperature radiator or a 'old fashioned' fireguard arrangement.

Could you put the towel rail in series/downstream of the DHW cylinder so its feed water would be cooler?

[johnrae]

How about one of these with the thermal bulb strapped to the radiator

http://www.bhl.co.uk/uploads/article331/Danfoss_RAVI.pdf

jack

[Baz]

Are the feed pipes on the skirting or safely below the floor? Is it really unsafe? We had such a towel rail when I was 3 and I don't have any scars.
You can reduce the boiler output by fitting firebricks or insulating millboard over part of the walls of the firebox. This won't help the water temp however.