room temperature

[dennisb66]

How many degrees should the room temp.fall before the thermostat kicks in to fire up the boiler. My radiators get very cold and subsequently the rooms before the boiler fires up. I have a Danfoss TP5 thermostat(7 years old) and I have changed the batteries but it's made no difference.

 

[davebgas]

turn the boiler stat up....., do you have TRV's or closed radiators anywhere in the house?

 

[david17uk]

Some people do get mixed up... the radiators may be off and cold, but the room may still be warm.

Most digital room stats that I've installed wait for it to drop 0.5 degrees below the set temperature before they call for heat

 

[jimstreet]

if it is a digital stat then yes it is 0.5 degress, but if it is an old dial one then generally it will be betwwen 1 and 3 degrees

 

[dennisb66]

Thanks for your replies guys, I don't have any TVR's fitted or closed radiators. My Alpha CB 24 boiler has a radiator thermostat from 1 to 9 it was set at 7 , I have increased it to 8 to see if there is any difference, I had wondered whether my room thermo was at fault.

 

[johnfox]

has it aways been like that or you trying to run it at reduced tp5 temperature.
is your tp5 near a radiator so that area probaly a hall/landing keeps a reasonable temp.
if so govern down rad adjacent to tp5 on locking shield valve.

 

[Onetap]

My radiators get very cold and subsequently the rooms before the boiler fires up. I have a Danfoss TP5 thermostat(7 years old) and I have changed the batteries but it's made no difference.

Are they pressed steel radiators?

 

[dennisb66]

Onetap.......Are they pressed steel radiators

Yes

Johnfox......has it aways been like that or you trying to run it at reduced tp5 temperature.
is your tp5 near a radiator so that area probably a hall/landing keeps a reasonable temp.
if so govern down rad adjacent to tp5 on locking shield valve.

Certainly been this way for a long time,TP5 is on bottom stair landing,radiator in hallway about 5 feet away so yes it's possible the stair landing area is being kept warmer than rest of house,so turning it down may help,will give it a try.TP5 temp is normally set at 20c.

 

[bhm1712]

when the room stat turns the heating off the radiators will get cold, for example if it takes 20 mins for the room to drop 1 degree and the thermostat has a 1 degree differential, if it were set at 20 degrees, when it reached 20 degree, the heating would go off. in 15 mins the rads will be cooled off, then when the room temp is 19 degrees the stat will turn on the heating again
until it is at 20 degree again.

its normal,

 

[dennisb66]

Cheers bhm1712