Do I need a master themrmostat if rads have individual thermostats?

ahfh1

Hi,

I have just bought this heating timeswitsch and thermostat (to be placed in the hallway):

http://www.honeywelluk.com/products/Systems/Wireless-Enabled/Sundial-RF2-Pack-1/

Do I really need a 'master' thermostat to be placed in the hall, if all individual radiators aorund the house have their own rad thermostat?

Thanks

ormus

yes. how else are you gonna tell the boiler to switch on or off?
a time switch isnt much use in the summer/warmer months.

DVardysShadow

Yes you do need a thermostat in a room without a thermostatic valve on the rad. Otherwise, all of the thermostatic valves could shut with the boiler running. Not good.

Bonbon

It probably depends on what boiler you have. All the rads in my house have thermostatic valves and I don't have a wall thermostat. My old Potterton boiler has a dial which I can set minimum-5. I have always presumed that it tells the boiler how much to fire up and each rad will turn off when it gets to temperature.

ahfh1

I will still have a timer connected to the boiler to tell the boiler when the heating will come on.

The rad in the hall will have a thermostatic valve (as will all the other rooms in the house). So does that mean there's no need for the traditional dial type thermostat that you normally see in the hallway/landing in houses? Don't see the point of having it if all rads have their own thermostat.

DVardysShadow

ahfh1 wrote: »

I will still have a timer connected to the boiler to tell the boiler when the heating will come on.

The rad in the hall will have a thermostatic valve (as will all the other rooms in the house). So does that mean there's no need for the traditional dial type thermostat that you normally see in the hallway/landing in houses? Don't see the point of having it if all rads have their own thermostat.

But if all the radiators reach temperature, there will be no flow through your system and your boiler will set there boiling water for no good purpose. Some boilers do not like this treatment and start banging and spewing hot water into overflow tanks. Some are fine - but they burn enough gas to pay for your thermostat every few months.

Homersimpson

You can have a TRV on every rad but if you do this its important to fit a sprung bypass to the system so that when all the rads shutdown the water can continue to flow around the system back to the boiler. If the water coming back to the boiler is at the same temperature its sent out at then the boiler shutsdown.

A better way of achieveing this to have a radiator in the coldest room (usually the hall) with no TRV (just lockshield valves) and a thermostat which switches off the system when the hall is up to temperature.

By doing this the boiler isn't cycling as the return water cools down. (I.e. heat is only produced when there is demand).