Controlling heated towel rail

[Peter]

I was wondering how I should setup my heated towel rail. Is it possible for a radiator controller to control the radiator valve but not call the boiler?

I wouldn't really want the boiler to come on just for the towel rail but if the boiler is on for another room then it would be nice for some heat to go through the towel rail (unless it's getting too hot). Equally, I wouldn't want the rail hot 24hrs/day. Is there a way to do this? What do others do for their towel rails?

[Richard]

Mine are controlled with HR92's...

[rogg]

Pre Evohome but with ten motorised valves the towel rails (three) had their own valve. The "valve open" switches on all the valves were connected in parallel such that any open valve would "make the circuit" and fire up the boiler and pump. The return temperature from the towel rails was monitored by a pipe stat such that when it reached a preset temperature it would close the valve and shut down the boiler until it had cooled down and the process repeated.

With the Evohome which I am installing right now I am using the built in thermostat in the controller set at 30 degrees (when I want the towel rails on) or 5 degrees ( when off) and then routing the output from the Wireless Relay Box through the pipe thermostat as described above.

In simple terms, when towel rail operation required controller commands heat (30 deg) >>>>> Wireless Relay Box outputs heat required signal to Pipe Stat >>>> If towel rails cool pipe stats internal switch is closed and the signal routed to the motorized valve which opens (internal switch closed) and onto the boiler >>>> when pipe stat commanded temp reached the pipe stats internal switch opens >>>> motorized valve (with no signal) closes and boiler shuts down. With no flow past the pipe stat the stat slowly cools down and when its internal switch closes the process repeats.

When the towel rails are not required the command temperature is set at 5 degrees >>>> no signal to
Wireless Relay box >>>> hence no signal to motorized valve which remains closed >>>> no signal to the boiler.

Am very willing to be shot down in flames if you don't think it will work.

It could have been made much easier if instead of using the wall thermostat to trigger the Wireless Relay box Evohome had come up with a suitable pipe stat that did the same . I did think of trying the tank thermostat left over from the hot water tank sensing (the thermal store has a pocket so will be using the probe and hence have the redundant tank stat). Am told that this stat will not communicate direct to a wireless relay box which would have made the process much easier. Would love to find out this information is incorrect.

Over to you far more informed members .......