Room temperature never reaches desired thermostat temperature - what else can I do?

chris_n

Could you measure the radiators, and type then we can work out how many kW they can put out.

Have a look at https://www.heatandthings.com/what-is-the-difference-between-a-type-11-type-21-and-type-22-radiator/

The one in your picture looks like a type 21 (double radiator, single finned).
I think we can discount the boiler being undersized.

Scrounger

Could be the radiator lockshield valves that need adjusting.

Scrounger

Aylesbury_Duck

ireallycantyodel said:

chris_n said:

Dolor said:

Heating is simple physics. You set a temperature. This temperature will be reached when the heat entering the home equals the heat that the house is losing to the atmosphere.

Turning down the boiler flow temperature will increase the time needed to reach a set temperature. Indeed, the set temperature may never be reached.

It follows that:

Your boiler is too small for your home. Most are for an outside air temperature of Minus 7.

Your emitters are too small for the rooms that they are in. This could be down to radiator size.

Your heating system needs to be power flushed. Sludge causes radiator blockages and slow water flow.

Your home is poorly insulated.

Or a mix of all of the above.

It's a 30kW to the radiators boiler so unless this is a mansion it isn't too small even at -7. How big is the house, how many radiators, single or double radiators, are the radiators finned? Are the radiators all hot all over? A quick look at the controller suggests it may possibly have a modulating function designed to stop the temperature overshooting but I would concentrate on the radiators for now.

First of all thanks so much for all these useful answers so far.

To answer your question Chris I had to look up what finned radiators are and I am still not quite sure tbh. The house is fairly small, just 2 bedrooms (the second bedroom is tiny but does get warm). The other bedroom is big-ish but only has a single radiator (it's also the coldest room). The radiator in the living room is a double radiator like this one but spreads across the bay window:



With regards to bleeding them, all radiators are the same temperature throughout so didn't think they need to be bled but I think it's something I can definitely try anyway.

The home is definitely not well insulated - at least the walls aren't. There is not much I can do at the moment as I am renting. But the roof is well insulated. I do feel a lot of heat goes out through the walls though.


Edit:

The flow temperature was reduced but it only affected the time it takes to heat up the house, the temperature hasn't changed so it's 14 degrees most of the time

This might be part of the problem.  Bay windows are often poorly-insulated because they sit outside the normal property footprint.  If the roof of the bay isn't well-insulated, it'll be an obvious cold spot that your nice double radiator is struggling to overcome.  Can you box off the bay with some thermal curtains, or is the radiator literally inside the bay itself?

BUFF

where is the room 'stat situated?
when you say that the room never gets above 14C is that being measured in the same place as the 'stat or somewhere else in the room?

Any TRV in  the same room as the 'stat needs set to maximum.

InvertedVee

ireallycantyodel said:

I have a Glowworm Ultimate2 30c boiler with a Glowworm Climapro2 Thermostat. My issue is that the room temperature never reaches the desired thermostat temperature which is set to 18.5 c. As a result, the heating is on all day.

The flow temperature is set to 65 now to save some money (it was 80 but even when it was higher, the room temperature was never reached). The highest it goes is 14 degrees at the moment (on a frosty winter day) even when the heating is on all day.

I have recently bought some radiator reflector panels and am planning to install a shelf above the radiators to see if it makes a difference. Apart from the bathroom all radiators in the house have TRV's fitted and I am not sure if I should set them to max or turn them to low to let the thermostat do its thing? The radiators are warm to the touch throughout but never so hot that they are untouchable. The radiators in the biggest room are rather large/long so I don't think it's the radiator size but they are situated underneath the bay windows. It's an old council house and the roof is well insulated but the walls are cold to the touch (no cavities) but there is not much I can do about the latter at the moment. Would that undermine the room temperature or is there anything else I can do?

Hi, let's see if we can help.

Is this a new issue for you, or has it performed like this for a long time?

I've done some digging and read the manual for your thermostat and your boiler.

Is the room thermostat in the best location? Here's an extract from the manual:



First note that the boiler manual (p12) says that the user can set the maximum flow temperature but if the weather compensation external sensor is used, the actual flow temperature will be set by the boiler.

I wonder if some of the settings have been fiddled with or poorly commissioned. A few things for you to check in the installer menu:

1. Check that the maximum permissible room temperature is set to 30C and the room correction factor is 0C.
2. Turn off the modulating mode for a day. (This is an energy-saving feature, so I'd recommend turning it on again later. But it will be helpful to know if the modulation is part of the issue).
3. Check and make a note of the heating curve gradient setting. If it's different from the factory setting, which is 1.6, try changing it to 1.6. (It's important to make a note because after a couple of days experimenting, you might want to return it to where it was).

I wouldn't be surprised if a poorly-chosen weather modulation curve is the issue at a time when the external temperatures are unusually cold. This cold spell may have revealed a poor set-up which you haven't noticed in other seasons.

ireallycantyodel

chris_n said:

Could you measure the radiators, and type then we can work out how many kW they can put out.

Have a look at https://www.heatandthings.com/what-is-the-difference-between-a-type-11-type-21-and-type-22-radiator/

The one in your picture looks like a type 21 (double radiator, single finned).
I think we can discount the boiler being undersized.

Right, finally found my tape measure:

The bedroom radiator is one like this and it's 255 cm long (I guess this is just another, slimmer version of the Type 11 ones because it has no visible fins)


The one in the living room, after checking, is a type 21 - Only one layer of fins but enclosed in two panels.

It's 130 cm long.

Aylesbury_Duck said:

ireallycantyodel said:

chris_n said:

Dolor said:

Heating is simple physics. You set a temperature. This temperature will be reached when the heat entering the home equals the heat that the house is losing to the atmosphere.

Turning down the boiler flow temperature will increase the time needed to reach a set temperature. Indeed, the set temperature may never be reached.

It follows that:

Your boiler is too small for your home. Most are for an outside air temperature of Minus 7.

Your emitters are too small for the rooms that they are in. This could be down to radiator size.

Your heating system needs to be power flushed. Sludge causes radiator blockages and slow water flow.

Your home is poorly insulated.

Or a mix of all of the above.

It's a 30kW to the radiators boiler so unless this is a mansion it isn't too small even at -7. How big is the house, how many radiators, single or double radiators, are the radiators finned? Are the radiators all hot all over? A quick look at the controller suggests it may possibly have a modulating function designed to stop the temperature overshooting but I would concentrate on the radiators for now.

First of all thanks so much for all these useful answers so far.

To answer your question Chris I had to look up what finned radiators are and I am still not quite sure tbh. The house is fairly small, just 2 bedrooms (the second bedroom is tiny but does get warm). The other bedroom is big-ish but only has a single radiator (it's also the coldest room). The radiator in the living room is a double radiator like this one but spreads across the bay window:



With regards to bleeding them, all radiators are the same temperature throughout so didn't think they need to be bled but I think it's something I can definitely try anyway.

The home is definitely not well insulated - at least the walls aren't. There is not much I can do at the moment as I am renting. But the roof is well insulated. I do feel a lot of heat goes out through the walls though.


Edit:

The flow temperature was reduced but it only affected the time it takes to heat up the house, the temperature hasn't changed so it's 14 degrees most of the time

This might be part of the problem.  Bay windows are often poorly-insulated because they sit outside the normal property footprint.  If the roof of the bay isn't well-insulated, it'll be an obvious cold spot that your nice double radiator is struggling to overcome.  Can you box off the bay with some thermal curtains, or is the radiator literally inside the bay itself?

The radiator is right under the window unfortunately - so if I get curtains it will also cover the radiator

I am looking to install a shelf to sit right above the radiator though.

BUFF said:

where is the room 'stat situated?
when you say that the room never gets above 14C is that being measured in the same place as the 'stat or somewhere else in the room?

Any TRV in  the same room as the 'stat needs set to maximum.

I have set the TRV's to max now. The thermostat is in the living room on an inside wall - pretty much in the centre of the house.

I took the thermostat with me into the bedroom to measure them temperature there - so to be clear:

The living room is 16c and the bedroom is 14c after the radiators have been running for a while. Thing is, I work in my bedroom as I am working from home so it gets quite chilly.

Since this morning the temp, as described earlier, hasn't budged and it's still trying to get to 18.5

ireallycantyodel

M0KBJ said:

ireallycantyodel said:

I have a Glowworm Ultimate2 30c boiler with a Glowworm Climapro2 Thermostat. My issue is that the room temperature never reaches the desired thermostat temperature which is set to 18.5 c. As a result, the heating is on all day.

The flow temperature is set to 65 now to save some money (it was 80 but even when it was higher, the room temperature was never reached). The highest it goes is 14 degrees at the moment (on a frosty winter day) even when the heating is on all day.

I have recently bought some radiator reflector panels and am planning to install a shelf above the radiators to see if it makes a difference. Apart from the bathroom all radiators in the house have TRV's fitted and I am not sure if I should set them to max or turn them to low to let the thermostat do its thing? The radiators are warm to the touch throughout but never so hot that they are untouchable. The radiators in the biggest room are rather large/long so I don't think it's the radiator size but they are situated underneath the bay windows. It's an old council house and the roof is well insulated but the walls are cold to the touch (no cavities) but there is not much I can do about the latter at the moment. Would that undermine the room temperature or is there anything else I can do?

Hi, let's see if we can help.

Is this a new issue for you, or has it performed like this for a long time?

I've done some digging and read the manual for your thermostat and your boiler.

Is the room thermostat in the best location? Here's an extract from the manual:



First note that the boiler manual (p12) says that the user can set the maximum flow temperature but if the weather compensation external sensor is used, the actual flow temperature will be set by the boiler.

I wonder if some of the settings have been fiddled with or poorly commissioned. A few things for you to check in the installer menu:

1. Check that the maximum permissible room temperature is set to 30C and the room correction factor is 0C.
2. Turn off the modulating mode for a day. (This is an energy-saving feature, so I'd recommend turning it on again later. But it will be helpful to know if the modulation is part of the issue).
3. Check and make a note of the heating curve gradient setting. If it's different from the factory setting, which is 1.6, try changing it to 1.6. (It's important to make a note because after a couple of days experimenting, you might want to return it to where it was).

I wouldn't be surprised if a poorly-chosen weather modulation curve is the issue at a time when the external temperatures are unusually cold. This cold spell may have revealed a poor set-up which you haven't noticed in other seasons.

Thank you, the thermostat is situated in the best possible place in the house which is an internal, central wall in the living room.

When it comes to heating curves I am not entirely sure if I know where to do that. Because I have the Climapro, certain settings on the boiler are inaccessible and need to be adjusted by an engineer. The only way I was able to change the flow temp was by calling customer services who were a little bit reluctant. Before I adjusted it, the FT was 80 degrees and even they agreed that's a bit steep and it was costing quite a lot without getting much in return as the room wasn't much warmer.

But I'll have a butchers in the manual to see if I can make the adjustments as described in your post. It's our second winter here but last year wasn't as cold (or as expensive) so I didn't pay too much attention.

Aylesbury_Duck

Anything you can do to improve the insulation of that bay window?  Putting more insulation inside the void above it?  Gluing insulated panels to its ceiling and then fitting a new "false ceiling" to hide them?

BUFF

ireallycantyodel said:

chris_n said:

Could you measure the radiators, and type then we can work out how many kW they can put out.

Have a look at https://www.heatandthings.com/what-is-the-difference-between-a-type-11-type-21-and-type-22-radiator/

The one in your picture looks like a type 21 (double radiator, single finned).
I think we can discount the boiler being undersized.

Right, finally found my tape measure:

The bedroom radiator is one like this and it's 255 cm long (I guess this is just another, slimmer version of the Type 11 ones because it has no visible fins)


The one in the living room, after checking, is a type 21 - Only one layer of fins but enclosed in two panels.

It's 130 cm long.

Aylesbury_Duck said:

ireallycantyodel said:

chris_n said:

Dolor said:

Heating is simple physics. You set a temperature. This temperature will be reached when the heat entering the home equals the heat that the house is losing to the atmosphere.

Turning down the boiler flow temperature will increase the time needed to reach a set temperature. Indeed, the set temperature may never be reached.

It follows that:

Your boiler is too small for your home. Most are for an outside air temperature of Minus 7.

Your emitters are too small for the rooms that they are in. This could be down to radiator size.

Your heating system needs to be power flushed. Sludge causes radiator blockages and slow water flow.

Your home is poorly insulated.

Or a mix of all of the above.

It's a 30kW to the radiators boiler so unless this is a mansion it isn't too small even at -7. How big is the house, how many radiators, single or double radiators, are the radiators finned? Are the radiators all hot all over? A quick look at the controller suggests it may possibly have a modulating function designed to stop the temperature overshooting but I would concentrate on the radiators for now.

First of all thanks so much for all these useful answers so far.

To answer your question Chris I had to look up what finned radiators are and I am still not quite sure tbh. The house is fairly small, just 2 bedrooms (the second bedroom is tiny but does get warm). The other bedroom is big-ish but only has a single radiator (it's also the coldest room). The radiator in the living room is a double radiator like this one but spreads across the bay window:



With regards to bleeding them, all radiators are the same temperature throughout so didn't think they need to be bled but I think it's something I can definitely try anyway.

The home is definitely not well insulated - at least the walls aren't. There is not much I can do at the moment as I am renting. But the roof is well insulated. I do feel a lot of heat goes out through the walls though.


Edit:

The flow temperature was reduced but it only affected the time it takes to heat up the house, the temperature hasn't changed so it's 14 degrees most of the time

This might be part of the problem.  Bay windows are often poorly-insulated because they sit outside the normal property footprint.  If the roof of the bay isn't well-insulated, it'll be an obvious cold spot that your nice double radiator is struggling to overcome.  Can you box off the bay with some thermal curtains, or is the radiator literally inside the bay itself?

The radiator is right under the window unfortunately - so if I get curtains it will also cover the radiator

I am looking to install a shelf to sit right above the radiator though.

Get shorter curtains that don't drop to the floor over the radiator or the shelf that you said that you are planning to fit above the radiator.
You want to leave a reasonable amount of space (15cm+) between the top of the rad & the shelf to allow the convected air to flow up through the rad & out into the room.

Spoonie_Turtle

ireallycantyodel said:

chris_n said:

Could you measure the radiators, and type then we can work out how many kW they can put out.

Have a look at https://www.heatandthings.com/what-is-the-difference-between-a-type-11-type-21-and-type-22-radiator/

The one in your picture looks like a type 21 (double radiator, single finned).
I think we can discount the boiler being undersized.

Right, finally found my tape measure:

The bedroom radiator is one like this and it's 255 cm long (I guess this is just another, slimmer version of the Type 11 ones because it has no visible fins)


The one in the living room, after checking, is a type 21 - Only one layer of fins but enclosed in two panels.

It's 130 cm long.

Aylesbury_Duck said:

ireallycantyodel said:

chris_n said:

Dolor said:

Heating is simple physics. You set a temperature. This temperature will be reached when the heat entering the home equals the heat that the house is losing to the atmosphere.

Turning down the boiler flow temperature will increase the time needed to reach a set temperature. Indeed, the set temperature may never be reached.

It follows that:

Your boiler is too small for your home. Most are for an outside air temperature of Minus 7.

Your emitters are too small for the rooms that they are in. This could be down to radiator size.

Your heating system needs to be power flushed. Sludge causes radiator blockages and slow water flow.

Your home is poorly insulated.

Or a mix of all of the above.

It's a 30kW to the radiators boiler so unless this is a mansion it isn't too small even at -7. How big is the house, how many radiators, single or double radiators, are the radiators finned? Are the radiators all hot all over? A quick look at the controller suggests it may possibly have a modulating function designed to stop the temperature overshooting but I would concentrate on the radiators for now.

First of all thanks so much for all these useful answers so far.

To answer your question Chris I had to look up what finned radiators are and I am still not quite sure tbh. The house is fairly small, just 2 bedrooms (the second bedroom is tiny but does get warm). The other bedroom is big-ish but only has a single radiator (it's also the coldest room). The radiator in the living room is a double radiator like this one but spreads across the bay window:



With regards to bleeding them, all radiators are the same temperature throughout so didn't think they need to be bled but I think it's something I can definitely try anyway.

The home is definitely not well insulated - at least the walls aren't. There is not much I can do at the moment as I am renting. But the roof is well insulated. I do feel a lot of heat goes out through the walls though.


Edit:

The flow temperature was reduced but it only affected the time it takes to heat up the house, the temperature hasn't changed so it's 14 degrees most of the time

This might be part of the problem.  Bay windows are often poorly-insulated because they sit outside the normal property footprint.  If the roof of the bay isn't well-insulated, it'll be an obvious cold spot that your nice double radiator is struggling to overcome.  Can you box off the bay with some thermal curtains, or is the radiator literally inside the bay itself?

The radiator is right under the window unfortunately - so if I get curtains it will also cover the radiator

We have that problem too in the downstairs rooms (external windows, not a whole bay like yours but recessed in an attempt to create that impression).  We've tried to get curtains that reach the sill and no lower; they've just arrived for the coldest room so we'll find out next week when we can get them fitted whether that plan worked.  We have thermal blinds already inside the recess but obviously curtains should be much better without the gaps.