Question about wall heating thermostat

mrvillicus

I have quite an old heating system which comprises of an old gas boiler (1991) radiators with non thermostatic valves and a wall mounted thermostat in my hallway.

I understand the wall stat controls the boiler to turn on or off once the set temperature is achieved however my stat only reaches 19, if I go below 19 it clicks and turns the boiler off so as far as I can gather it'll only set the temp to 19 or above, is this normal?

boliston

I find hallway thermostats are pretty useless and just use them as an on/off switch - the temperature control on the boiler itself is far more accurate for temperature setting

elsien

Is it because the temperature in the room where the thermostat is is always above 19?

mrvillicus

As my boiler is so old all it has is a knob which ranges from 1-5 so I'm guessing that controls the water temperature?

mrvillicus

The wall stat actually clicks though at 19 so it's as if this is it's preset setting or something but to answer your question I would guess the temp drops below 19 especially at night

boliston

mrvillicus wrote: »

As my boiler is so old all it has is a knob which ranges from 1-5 so I'm guessing that controls the water temperature?

My boiler (about 13 years old) only has a knob to control radiator temperature - the water is always quite hot even if the radiator temperature knob is kept very low (i live in a top floor flat which does not require really hot radiators, even in cold weather)

nofoollikeold

Thermostats click when you turn the dial through the temperature of the room. If you want to see how accurate it is, use an accurate thermometer to measure the temperature, then see if the thermostat clicks at that temperature. On some of them you can remove the knob and replace it at a position so that what is indicated is the actual temperature.

They are generally only accurate to about +- 2 or 3 degrees, although some are better.

Ectophile

The idea of a thermostat is that you select the temperature you want, then just leave it alone.

When the temperature in that room drops below the temperature you've set, the heating comes on. When it goes above that temperature, the heating goes off.

They aren't particularly accurate. But you should be able to find the setting that is comfortable you, whether it's accurate or not.

boliston

Ectophile wrote: »

The idea of a thermostat is that you select the temperature you want, then just leave it alone.

When the temperature in that room drops below the temperature you've set, the heating comes on. When it goes above that temperature, the heating goes off.

They aren't particularly accurate. But you should be able to find the setting that is comfortable you, whether it's accurate or not.

I find that I often feel "hot" or "cold" but it's not always exactly related to the room temperature, so I have always switched on the heating if I'm hot and switched it off if I'm cold - I'm not keen on auto control as it could come on when I'm out (or asleep) and waste energy

getmore4less

One critical factor with thermostats is the range they switch on/off and the hysteresis of the system.

if they don't match you can get swings in the temp bigger than the "comfortable" range.

as the room(s) get cooler you want the heating to come on in time to warm up and start heating before it gets too cold and when warming up to switch off before it gets too warm as it carries on heating for a bit.

with a traditional(old) setup the controller does the timings(on/off) and the thermostat sets a temp.
You have to guess when to turn it on and when to turn it off to get your core time around the right temps.

Things have moved on and these days(also a simple upgrade to an older system) is a programmable thermostat.

With these you can set multiple time/temp combinations

Many now have some built in compensation to do start up and coll down periods.
often have tighter control over the temp range and some are adjustable so you can better match your system

They have holiday modes so if away you can turn the heating off and set it on just before you come back.

and they have other useful features(like boost) and some you never use.

most of us have fairly predictable lives so can find setting that work and override for the times when you go off routine, most have at least 2 separate days type so you can do say Mo-Fri & Sat-Sun, and there are 7 day options so you can do each day differently.

an example of what you might do is have the heating come on in the morning to get up and get ready, if you do out turn it off, or if you are at home might drop the temp a bit because you are doing stuff, early afternoon back up to norm for the kids coming home or coming home from work, a little warmer for sitting watching TV and then down quite low(not off) overnight to stop it getting too cold.

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The boiler temp control is to adjust the amount of heat you can get into/out of the system not to control the temperature of the rooms.

Ectophile

boliston wrote: »

I find that I often feel "hot" or "cold" but it's not always exactly related to the room temperature, so I have always switched on the heating if I'm hot and switched it off if I'm cold - I'm not keen on auto control as it could come on when I'm out (or asleep) and waste energy

I just rely on a combination of a thermostat and timeswitch. For most of the year, I don't touch it, even in Summer. I might knock the thermostat down a few degrees if I'm going away, but that's about it.