Thermostat Control

bonnieprince

Hi All

Just wondering if someone can help with my issue, we have a house which has rads in each room with thermostats and we recently updated our heating system to a three zone (upstairs,downstairs & hot water) timer and a condensing boiler.

Can anyone advise what should the rads be set to?
The upstairs and downstairs thermostats are set to about 21 degrees but we find that some rooms are too hot and some the rads rarely come on.

Any ideas or suggestions would be gratefully appreciated
bp

DGOBS

To be honest, I really ignore actual set values, my only concern is 'room temperature' and I would just keep slowly turning up/down over a period of a few days until all rooms feel comfortable, you may just want a very low heat in little or unused rooms, or I prefer lower bedroom temperature

DoneDL

Try turning the upstairs stat to about 18oC and see if the rooms are warm enough. The manufacturer will list the heat setting that the TRV will give you on each number.

TheBardWest

Hope you don't mind a minor thread hijack here - I've just had the heating controls in our place replaced with a similar setup: 3 zone timer and TRV on all the rads. I understand the timer controls the time that the boiler fires + which zones are open, and that each TRV controls the flow of hot water into each rad. What I don't understand (coming from an older thermostatic system) is when/if the boiler shuts off due to reaching an ambient temperature of X? Or does the boiler just fire the whole time when the timer tells it, even if all the TRVs are closed because the house is 'warm enough'...?

Outkast_IRE

TheBardWest wrote: »

Hope you don't mind a minor thread hijack here - I've just had the heating controls in our place replaced with a similar setup: 3 zone timer and TRV on all the rads. I understand the timer controls the time that the boiler fires + which zones are open, and that each TRV controls the flow of hot water into each rad. What I don't understand (coming from an older thermostatic system) is when/if the boiler shuts off due to reaching an ambient temperature of X? Or does the boiler just fire the whole time when the timer tells it, even if all the TRVs are closed because the house is 'warm enough'...?

I believe if you want to get technical about it you should not have the trvs in the same rooms as the thermostats , in reality what you do is in the rooms with the wall thermostat leave the trvs open full .

The trvs wont shut off the boiler directly, but the boiler may will sense that the heated water isnt leaving the boiler and it wont run again until necessary.

If all the thermostats go off the boiler should as such shut off as there will be no demand whatsoever.

DGOBS

What should be installed is 'boiler interlock' not a single control but controls in series so the boiler doesn't fire unless there is demand for heat, here is the sequence

Time clock/programmer allows for time control of zones and sends power to the room and cylinder thermostats

Room/cylinder thermostats receive power from the timer and measure cylinder or room ambient temperature, if what's measured is below the set point the switch stat closes bd sends power to the motorised valves (or pumps for system link type controls)

MV valves control flow to the zone, receives power from the room/cylinder stats and once energised they open the water valve underneath to accept water from the boiler, but as they open they also have an auxiliary switch which sends power to the switched live of the boiler to signal that het is required and the boiler fires up (demand)

TRVs are a further control for individual rooms, but do not signal to the boiler, so should only be used as an additional control, not on their own as the boiler would keep firing even without any heat requirement for the house, the boiler would star 'short cycling' and the same as stop starting your car in traffic, your fuel consumption would go up even though you don't actually need any heat!