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Room thermostat. Why?

OP's question was quite simple to answer. The TRVs only control the heat of the rads but not the boiler. The room stat is there to turn the boiler off and on. Without it you'd have to manually turn it on and off or it'd be on all the time (until overheat).

Doesn't the boiler have its own 'stat on the return water? Placing a thermostat in an unheated room will not control the boiler since it will be on all the time. And since I only turn the rads on (with the TVR) in the room I am occupying I would need to carry the 'stat around with me for it to be effective :-)
 
Doesn't the boiler have its own 'stat on the return water? Placing a thermostat in an unheated room will not control the boiler since it will be on all the time. And since I only turn the rads on (with the TVR) in the room I am occupying I would need to carry the 'stat around with me for it to be effective :-)

The stat should not be fitted in an unheated room
 
Doesn't the boiler have its own 'stat on the return water? Placing a thermostat in an unheated room will not control the boiler since it will be on all the time. And since I only turn the rads on (with the TVR) in the room I am occupying I would need to carry the 'stat around with me for it to be effective :-)

The stat should not be fitted in an unheated room

Absolutely, otherwise it would be a waste of time.

The BS says:

The heating system shall be provided with means to limit the temperature of the spaces it is heating.

The return temp does not effectively tell the boiler what the room temperatures are.

Also:

Where individual thermostatic radiator valves (TRVs) are used they shall not be the sole means of control for the heating circuit but shall be used in conjunction with other controls which ensure that the boiler is shut off, or reduced to minimum burning rate for solid fuel, when not required.
 
Absolutely, otherwise it would be a waste of time.

The BS says:The BS says:


The heating system shall be provided with means to limit the temperature of the spaces it is heating.


Fair enough if that is the regs. But which room should |I put the 'stat in bearing in mind that any room in the house can be unheated at some time or other.
 
Fair enough if that is the regs. But which room should |I put the 'stat in bearing in mind that any room in the house can be unheated at some time or other.

It's supposed to be in the room with the rad that doesn't have a TRV but if you get a wireless stat+programmer then you can have it in whichever room you like. My house came with a programmer in the hall so I removed that and put the wireless receiver in its place.
 
Fair enough if that is the regs. But which room should |I put the 'stat in bearing in mind that any room in the house can be unheated at some time or other.


Why do you heat your house in such a disorganised way? Surely it would be more efficient to have the TRV's down low on little used rooms and higher in the rooms you used more - and in one of these is where the thermostat should be placed!
 
Fair enough if that is the regs. But which room should |I put the 'stat in bearing in mind that any room in the house can be unheated at some time or other.

"Hello dcbwhaley",

The reason for having a Room Thermostat and why it is a requirement of Part L of the Building Regulations [Energy Efficiency] has already been explained by some of the other Members but here is my version:

The reason why installing Room Thermostat is specified in Part L of the Building Regulations regarding Energy Efficiency is that without one Boilers would keep firing / going On & Off throughout the timed `ON` periods to satisfy the BOILER THERMOSTAT setting - this could be MANY times per timed `ON` period - with possibly as many as 70% of those being UNNECESSARY Firings - depending on the Temperature of the House / how many Radiator TRV`s were still open.

For THAT reason a Room Thermostat is viewed by the authors of Part L of the Building Regulations relating to Energy Efficiency - Professional Heating Engineers and Professional Electricians - such as the other Members on here who have advised You - as a `Must Have` Heating System Temperature Control.

Even if it was NOT a Regulation to install a Room Thermostat - common sense would dictate that it is a necessity - why waste Fuel to keep a Boiler Thermostat satisfied ?

I would Highly recommend that You look at fitting a Programmable Room Thermostat which would allow you to set different temperatures for different time periods during the Day /Night - personally I have my Home`s Programmable Room Thermostat operating just controlling the Temperature at different times throughout the Week - NOT as a `Timer` for the Heating system - I have a Honeywell Programmer for that.


There are Radio Frequency TRV`s and Receiving Units which can provide `Boiler Interlock` - IF ALL the RF TRV`s are closed down on their temperature settings then the Receiving Unit turns the Boiler Off until Heat is required again - these are very expensive Controls.

BUT - unless fitted to an `Ideal Home` regarding a `perfectly designed` Heating system / Insulation / double glazing etc. I am NOT convinced that this very expensive control system would ever be as Energy Efficient / Comfortable / effective as having a Programmable Room Thermostat and `normal TRV`s for Temperature Control.


I hope that this explanation `reinforces` what your Heating Engineer and the other Members on here advised You about the REQUIREMENT to have Room Thermostat fitted to your Home`s Heating system ?



With regard to WHERE to fit it - some of this has been mentioned above:

It should NOT be fitted in an unheated area OR in a Room that has an `additional heat source` - such a Gas Fire / Open Fire / or in Direct Sunlight - and obviously not too close to a Radiator / in a draught or behind curtains etc. [mentioned for less knowledgeable readers].

And the Radiator in the area where the Thermostat is sited should be correctly sized - that is VERY Important as this will be `controlling` the whole system / operating the Room Thermostat - and should not be able to be turned Off - it should have 2 Lockshield Radiator valves.

You must decide where the best location for the Room Thermostat is in your Home - based on that information.

Regards,

Chris
 
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