rads not going above 60

[chatlow]

Hi all

Not long liven in our new house - it has an old boiler system we are going to replace next year. Boiler is a Ideal classic (year ~2000 ish). It's heat only with thermal store cylinder in the airing cupboard. Has a Drayton programmer and we have both hot water and heating on for a few hours a few times a day. I bled all rads and no air came out.

Boiler is on 4/6 setting. Thermostat (drayton combi stat) is in hallway and seems unreliable but setting around 19-20, the rads are not really going over 55-60 most times.

Hot water seems fine, just the radiators. Any ideas?

 

[terryplumb]

You could turn up the boiler stat if the rads at 55/60 degrees don't give you the comfort level you desire.

 

[chatlow]

You could turn up the boiler stat if the rads at 55/60 degrees don't give you the comfort level you desire.

Do you mean the boiler level (literally got a selector switch 1-6)
Then the thermostat on the wall which doesn't seem to be doing an awful lot

 

[chatlow]

According the docs the temperature on level 4 (which it's on) is 72degrees. We are not seeing that with the rads

 

[muggles]

Turn it up to 5, it'll give you better hot water performance as well. Not really worth replacing that boiler unless you're also going to replace the thermal store - thermal stores are terrible news for condensing boiler efficiency as they have to run too hot in order to be effective.

 

[BlueLoo]

Hi all

Not long liven in our new house - it has an old boiler system we are going to replace next year. Boiler is a Ideal classic (year ~2000 ish). It's heat only with thermal store cylinder in the airing cupboard. Has a Drayton programmer and we have both hot water and heating on for a few hours a few times a day. I bled all rads and no air came out.

Boiler is on 4/6 setting. Thermostat (drayton combi stat) is in hallway and seems unreliable but setting around 19-20, the rads are not really going over 55-60 most times.

Hot water seems fine, just the radiators. Any ideas?

It's working as it should.

 

[chatlow]

Yeah we were weighing up costs to replace the boiler (and thermal store) or go for a combi

 

[chatlow]

Turn it up to 5, it'll give you better hot water performance as well. Not really worth replacing that boiler unless you're also going to replace the thermal store - thermal stores are terrible news for condensing boiler efficiency as they have to run too hot in order to be effective.

I'll give this a go tomorrow. Out of curiosity - with this heat store system (boiler is the ff240 btw) I was told that the hot water needs to be heated to a certain level before you turn on the heating to get the rads warm. I've therefore been setting the timer for both to come on for a few hours, few times a day.
Is there a need for the hot water to be on for the same amount of time? I'm used to a combi so this is all new to me

Thanks

 

[Dereekoo]

What speed have you got your pump set at

 

[chatlow]

What speed have you got your pump set at

Both set to 2 which I'm told is default

 

[Dereekoo]

Increase to 3 which is what I do if I want the radiators hotter on really cold days with the boiler stat set at its upper end

 

[chatlow]

Increase to 3 which is what I do if I want the radiators hotter on really cold days with the boiler stat set at its upper end

I'll increase boiler to 5 first and test. The speed at which the rads warm up isn't too bad, so hopefully just needs more heat from boiler

 

[muggles]

I'll give this a go tomorrow. Out of curiosity - with this heat store system (boiler is the ff240 btw) I was told that the hot water needs to be heated to a certain level before you turn on the heating to get the rads warm. I've therefore been setting the timer for both to come on for a few hours, few times a day.
Is there a need for the hot water to be on for the same amount of time? I'm used to a combi so this is all new to me

Thanks

Generally a thermal store is kept hot pretty much all the time, as allowing it to cool will reduce hot water performance.

 

[Ivor Windybottom]

The boiler temperature is a guide only, and is at the outlet of the boiler. Obviously the temperature will be lower at the radiators, as they lose heat into the room - this is exactly the thing that they are designed to do!

All boilers run more efficiently at a lower temperature. It's not just about rationing your heat, heating your house to say 20 degrees will cost more with hot radiators that are switching on/off than it would with less hot radiators. The hotter the water, the hotter the flue gas that's wasting heat by being blown into the air outside.

So if you're happy with the room temperature then definitely don't turn the boiler hotter, set it to a lower temperature. You should set the lowest flow temperature that is adequate for maximum efficiency.

 

[chatlow]

The boiler temperature is a guide only, and is at the outlet of the boiler. Obviously the temperature will be lower at the radiators, as they lose heat into the room - this is exactly the thing that they are designed to do!

All boilers run more efficiently at a lower temperature. It's not just about rationing your heat, heating your house to say 20 degrees will cost more with hot radiators that are switching on/off than it would with less hot radiators. The hotter the water, the hotter the flue gas that's wasting heat by being blown into the air outside.

So if you're happy with the room temperature then definitely don't turn the boiler hotter, set it to a lower temperature. You should set the lowest flow temperature that is adequate for maximum efficiency.

Understood, but we are not happy with overall room temperature, hence this thread and wanting to increase. Rads don't get to more than 55 usually, 58 if on for ages, which is lower than what's recommended (60-70)