Feeling Colder yet Thermostat at Same Setting.

david1946

Can a thermostat show one temperature yet operate at another temperature?

The thermostat is a Greenstar Comfort II RF and the boiler is a Worcester Greenstar condensing boiler.

When my new gas central heating with a combi boiler was installed 5 years ago the thermostat was set to 21 deg C during the day and 18 deg C during the night and the setting has never been altered since then.

Our old heating just had a thermostat numbered 0 to 9 that we turned on when needed.

We are usually in all day, both retired and in our late 70's.

Since the heating has been switched on this past 2 months we find that the temperature is not feeling as warm and comfortable in the evening yet the thermostat reading never goes below 20,5 deg C but we have to turn up the thermostat in the evening to 22.5 deg C to feel comfortable.

It always goes back to 21 deg C the next morning.

The only difference is that we had new double glazing fitted in July, we still wear the same layers of clothes etc.

I have noticed that the radiators, when they get hot as the heating cycles on and off, don't seem to feel as hot in the evening.

In the morning you can barely keep your hand on the radiators but in the evening you can. 

I put a new battery in the thermostat but that made no difference.

Is the thermostat getting faulty and we need a new one? 

JJ_Egan

Yes it can be faulty .

Test with a standard thermometer .

(

don't seem to feel as hot in the evening.)

Would not need to generate so much in a warm room .

badger09

david1946 said:

Can a thermostat show one temperature yet operate at another temperature?

The thermostat is a Greenstar Comfort II RF and the boiler is a Worcester Greenstar condensing boiler.

When my new gas central heating with a combi boiler was installed 5 years ago the thermostat was set to 21 deg C during the day and 18 deg C during the night and the setting has never been altered since then.

Our old heating just had a thermostat numbered 0 to 9 that we turned on when needed.

We are usually in all day, both retired and in our late 70's.

Since the heating has been switched on this past 2 months we find that the temperature is not feeling as warm and comfortable in the evening yet the thermostat reading never goes below 20,5 deg C but we have to turn up the thermostat in the evening to 22.5 deg C to feel comfortable.

It always goes back to 21 deg C the next morning.

The only difference is that we had new double glazing fitted in July, we still wear the same layers of clothes etc.

I have noticed that the radiators, when they get hot as the heating cycles on and off, don't seem to feel as hot in the evening.

In the morning you can barely keep your hand on the radiators but in the evening you can. 

I put a new battery in the thermostat but that made no difference.

Is the thermostat getting faulty and we need a new one? 

I don't know if this will help but...

We had new WB boiler fitted a few months ago, which is controlled by a HIVE thermostat.

Our installer placed the thermostat (which can be wall mounted, but ours isn't) in the hall which he said would be the coldest room in the house. He also removed the thermostat from the hall radiator.

In fact, the hall is NOT the coldest room, due to configuration of our bungalow. The thermostat would reach 20.5C as set, but the main living rooms were between 18 & 19C, which wasn't warm enough.

We've solved it by moving the thermostat!

coffeehound

david1946 said:

I have noticed that the radiators, when they get hot as the heating cycles on and off, don't seem to feel as hot in the evening.

In the morning you can barely keep your hand on the radiators but in the evening you can. 

Could it be that your hot water tank (if indeed you have one) is being heated in the evening, so is getting the heat from the boiler?

Also, what are the TRVs on the radiators set to?  Since it is cold in the morning, they would be letting the radiator get hotter, whereas in the evening when the room is warmer, they may throttle back to run the radiator less hot.  So they might just need turning up a bit

coffeehound

david1946 said:

Since the heating has been switched on this past 2 months we find that the temperature is not feeling as warm and comfortable in the evening yet the thermostat reading never goes below 20,5 deg C but we have to turn up the thermostat in the evening to 22.5 deg C to feel comfortable.

It always goes back to 21 deg C the next morning.

The only difference is that we had new double glazing fitted in July, we still wear the same layers of clothes etc.

Another thought:  is the location of the thermostat now warmer due to the new windows?  If it warms up more quickly, and stays warmer, then it will run the heating less and for shorter cycles.  If there is a radiator near to it, you might want to close the valve on it a bit so that it takes longer to warm up

wittynamegoeshere

It's always going to be likely that the temperature of the room varies due to the outside temperature.  The thermostat experiences the temperature of the place it happens to be, usually somewhere in the middle.  Of course it's going to be colder nearer to the outside wall or by the window if it's colder outside, especially if this is a long way from the heating and/or the thermostat.

It may be faulty, or it may just be reality.

BikingBud

david1946 said:

Can a thermostat show one temperature yet operate at another temperature?

The thermostat is a Greenstar Comfort II RF and the boiler is a Worcester Greenstar condensing boiler.

When my new gas central heating with a combi boiler was installed 5 years ago the thermostat was set to 21 deg C during the day and 18 deg C during the night and the setting has never been altered since then.

Our old heating just had a thermostat numbered 0 to 9 that we turned on when needed.

We are usually in all day, both retired and in our late 70's.

Since the heating has been switched on this past 2 months we find that the temperature is not feeling as warm and comfortable in the evening yet the thermostat reading never goes below 20,5 deg C but we have to turn up the thermostat in the evening to 22.5 deg C to feel comfortable.

It always goes back to 21 deg C the next morning.

The only difference is that we had new double glazing fitted in July, we still wear the same layers of clothes etc.

I have noticed that the radiators, when they get hot as the heating cycles on and off, don't seem to feel as hot in the evening.

In the morning you can barely keep your hand on the radiators but in the evening you can. 

I put a new battery in the thermostat but that made no difference.

Is the thermostat getting faulty and we need a new one? 

Depends entirely on the accuracy and calibration of the sensors (thermostat), as well as the ambient temperature and any possible temp compensation set up. From the user manual:

" This enhance load compensating function enables an intelligent conversation with the boiler to achieve the desired room temperature in the most efficient way possible.To help save the customer money by burning less fuel, and to minimise room temperature “overshoot” the boilers burner may stop firing just prior to the desired room temperature being reached. This behaviour including reduced radiator temperature is perfectly normal. The customer should simply set a temperature on the thermostat that they are comfortable with and allow the room thermostat and boiler to do their work."

Going from 0-9 or possibly even quoting 20.5 deg could be like the amp on spinal tap going up to eleven! Meaningless on its own.

With a new system you may need to adjust your expectations to how the system operates and especially how to operate the controls to achieve your own comfort.

You could bring in a calibrated thermometer possibly with data logging to track the temp trend through the day but will it make a difference to how you want the system to work, to be comfortable?

Has you energy consumption dropped? Possibly too early to determine with any certainty but if you set the required comfort level and still see savings you are winning.

Astria

BikingBud said:
" This enhance load compensating function enables an intelligent conversation with the boiler to achieve the desired room temperature in the most efficient way possible.To help save the customer money by burning less fuel, and to minimise room temperature “overshoot” the boilers burner may stop firing just prior to the desired room temperature being reached.

I found this to work in exactly the opposite way during the colder months: Yes, the boilers burner stops firing just prior to the desired room temperature, but that means that the room also cools down sooner and thus the boiler fires up again. I've also had it when it didn't achieve it's target temperature so it fired back up a second time to try and get to the target temperature. The result was that the boiler fired up more often, but for shorter periods of time.

After disabling this "Smart load compensating functionality", it now leaves the boiler running until it hits the desired temperature, meaning it can over shoot by 0.5c, but that also means that it takes longer to cool down and the end result is the boiler now fires about once per hour instead of several times per hour.

The actual difference in gas usage between the 2 modes is very slight, but it appears to actually cost slightly more under the "smart" mode, but within my measuring tolerance for error so I couldn't confirm one way or the other, so I went will "boiler and pump fires up less often - less wear and tear" and left it at that.

BikingBud

@Astria do you have a calibrated temperature monitoring and logging system? Where are you measuring your 0.5 deg C. Have you established any correction curves between your measured 0.5 deg C overshoot and the indicated boiler temp?

To be clear that is what the manual states. Many come on here and provide "advice" and comment about how systems may work but do not refer the OP to the best source; the manual! As I do not have that device I cannot say if the manual is accurate or otherwise. I did not read all of it but it is there for all to red online. Interestingly you are not able to confirm within your measuring tolerance if the compensating function works or not

What i did say is that what is important is that the OP achieves a satisfactory level of comfort which is different to setting a temperature as the OP is discovering.

Like I said above, it doesn't matter what the Spinal Tap amp says, 9 or 10 or 11 if its too quiet or too loud adjust it for your own comfort.

Also in the manual when, I went to read it further:

"Sensor calib. If it is suspected that the temperature display is off by a few degrees and if there is a precision temperature gauge/meter available, the display can be offset by ± 5 °C to compensate. The default value is 0.0 °C.

▶ Press the knob to enter the temperature offset function, the offset value is displayed, by default it is 0.0 °C.

▶ Press the knob and the display flashes.
▶ Turn the knob to adjust the temperature offset, between -3 and +3 °C.

▶ Press the knob to confirm the desired setting
▶ When the desired format has been selected, turn the knob to display Contrast"

I would deduce from this that they expect the sensor to be inaccurate and provide a method by which it can be adjusted if a precise meter can be used for comparison

 So offset as required then the OP can be happy that their comfort is achieved by setting the temp they expect to see on the stat rather than the stat being accurate.

[Deleted User]

david1946 said:

Since the heating has been switched on this past 2 months we find that the temperature is not feeling as warm and comfortable in the evening yet the thermostat reading never goes below 20,5 deg C but we have to turn up the thermostat in the evening to 22.5 deg C to feel comfortable.

It always goes back to 21 deg C the next morning.

The only difference is that we had new double glazing fitted in July, we still wear the same layers of clothes etc.

I have noticed that the radiators, when they get hot as the heating cycles on and off, don't seem to feel as hot in the evening.

In the morning you can barely keep your hand on the radiators but in the evening you can. 

I put a new battery in the thermostat but that made no difference.

Is the thermostat getting faulty and we need a new one? 

Where I live in the NE the outside temperture has plummeted in the last week and has really gone down further in the last couple of days with the combination of high winds and low temps (not to mention a power cut last night).

I have another gauge that I use to check that the themostat is what it is says it is and it does.  So that would be a cheap fix to see what is going on in all rooms of your house and not just where the thermosat is located.

However I have come to realise that a comfortable indoor temperature of say 20C with say an ambient outdoor of 10C always feels way warmer than the same 20C (which it is now) and an outdoor of 0C.   

BUFF

I hate to say it but it can also be part of the aging process https://www.mobilityhelp.co.uk/why-do-old-people-feel-cold/