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Wireless Thermostats & TRV's

Postby TheAbz » Mon Nov 10, 2008 12:01 pm

Im thinking about having a wireless thermostat installed along with my new boiler (Vaillant 838 ecotec exclusive).
Are these wireless thermostats any good and reliable as their wired counterparts?
Does anyone have one installed and possibly relate their experience?
I noticed in the brochure that other radio signals may interfere with wireless thermostats, how much of a problem is this in reality? Will Wireless broadband signals affect it?
Im going for the vaillant wireless one as the bolier is a vaillant.

TRVs. if im having a thermostat fitted, do i need to have TRVs on the radiators?

Thank you - if you need more info please ask.
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Postby plumbbob » Mon Nov 10, 2008 11:42 pm

Firstly, with a new boiler, you will have to have TRV's fitted.

I have fitted many wireless thermostats, and have never known any to have suffered from an interference problem. Very occasionally, I have seen the odd one lose communication and have to be reprogrammed, but it has never ended up as a re-occurring fault.

Personally, I would always use a wired one if the option was there. It's cheaper to buy, simpler, so got to be more reliable (if that's enough to be relevant) and has less batteries to change.
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Postby TheAbz » Tue Nov 11, 2008 3:08 pm

thanks plumbbob - now i just have to find a reliable person to fit my boiler and rads etc :D
Cheers once again
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Postby fuji0030 » Tue May 19, 2009 11:08 am

Wall thermostats, when fitted, are in series with the CH signal from the time-switch. Some have a built in resistor ("accelerator heater") to reduce the hysteresis, i.e. the "backlash" in temperature between switching on and switching off. When the thermostat is on, the resistor supplies a minute amount of heat, which makes the thermostat think that the room is slightly warmer than it is, and therefore makes it switch off again earlier. The room temperature will thus fluctuate less. Such thermostats require 3 cores and earth: live, switched output and neutral for the resistor. If live and switched output are interchanged, the resistor will be powered constantly and the advantage will be lost. Simpler/older thermostats only need 2 cores and earth, so if you're replacing a thermostat you might want to check the wiring beforehand to see if you can use this feature.

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