Burner always on when central heating on Ideal Logic Plus

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Hi,

I have a Ideal Logic Plus combi boiler.

When I turn on the central heating the burner is constantly on (at least the burner light indicator suggests it's always on). Is this normal? Seems to use a lot of gas when I use the central heating. I would have thought that the burner indicator would go on and off when needed rather than on all the time.

Also, I have turned the temp of the rads to 78 degrees. The rads are very hot to touch by hand but for some reason does not heat the room up very well. Is 78-80 degrees, for the rads, normal temps or would you expect higher or lower to heat a house properly? I'm not sure if it's the boiler at fault or bad insulation or maybe the rads not large enough?

Any thoughts/advice appreciated!
 
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If your rads are obscured or undersize, then they won't heat your rooms effectively. As far as radiators go, double convectors work best for circulating air in the room. They don't work too well with couches in front of them, or restrictive covers.
Modern boilers are modulating, they aren't designed to switch the burner on and off all the time because it's wasteful. Just because your burner is on doesn't mean it's at full rate. It's trying to maintain circuit temperature without going off.
 
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If your rads are obscured or undersize, then they won't heat your rooms effectively. As far as radiators go, double convectors work best for circulating air in the room. They don't work too well with couches in front of them, or restrictive covers.
Modern boilers are modulating, they aren't designed to switch the burner on and off all the time because it's wasteful. Just because your burner is on doesn't mean it's at full rate. It's trying to maintain circuit temperature without going off.

Thanks, good to know about the modulating boilers. Hope that is the case with mine.

They radiators might be undersized, I don't know as the gas engineer chose them. I do have a TV in front of mine. The warmest room, when the central heating is on, is the kitchen (which is normally the coldest room) which just so happens to have the biggest radiator (for some reason!).

To be honest, I don't even know i they're single or double convectors.

Does 80 degrees celcius sound right for the temp for the rads or is that too high, or too low, even though the room is still relatively cold?
 
Does the light go out if you turn the heating stat down to E or lower. You could find that the system is too big for the boiler so the boiler never gets up to temperature.
What programmer do you have and what is it set to as an opentherm one for this boiler overrides the heating stat on the boiler.
 
The burner will fire all the time provided the central heating water temperature isn't exceeding the set temperature.
So the losses from the radiators must be keeping the burner going
as it will modulate down to meet demand.
 
You never mentioned how many radiators the boiler is serving or how big the property is, at the moment it seems the boiler cant meet the demand of the property ie too many large size rads and too many long runs of pipe.
 
Does the light go out if you turn the heating stat down to E or lower. You could find that the system is too big for the boiler so the boiler never gets up to temperature.
What programmer do you have and what is it set to as an opentherm one for this boiler overrides the heating stat on the boiler.

I know it doesn't go out when I turn it to E, but I haven't tried any lower. Will try that next time I turn on the heating.

I don't think I have a programmer? Basically I just have the boiler and no separate control panel to the temperature. Is that what you mean?
 
The burner will fire all the time provided the central heating water temperature isn't exceeding the set temperature.
So the losses from the radiators must be keeping the burner going
as it will modulate down to meet demand.

So if that is the case, does it mean lack of insulation? Lack of power from the boiler? Need larger radiators?
 
You never mentioned how many radiators the boiler is serving or how big the property is, at the moment it seems the boiler cant meet the demand of the property ie too many large size rads and too many long runs of pipe.

It's only a small 2 bed terrace which has 6 radiators. None of which are that big. It's a 30kW boiler so I would assume that that shouldn't be the issue?
 
IF they were properly sized they would heat the room to 21 C with a flow temperature of just 70 C. Yours are obviously undersized.

Your installer is really the pitts as the installation, apart from the undersized rads, does not meet the Building Regulations having no room stat!

Was it a six rads and boiler for £1750 deal ?

Tony
 
IF they were properly sized they would heat the room to 21 C with a flow temperature of just 70 C. Yours are obviously undersized.

Your installer is really the pitts as the installation, apart from the undersized rads, does not meet the Building Regulations having no room stat!

Was it a six rads and boiler for £1750 deal ?

Tony

Hmm He did offer to install a separate control panel to control the temperature for extra money but didn't say it was necessary...

I think it was about £2.5k

So if the reason is undersized radiators, what are the possible solutions? Is it only install bigger rads? If so, how big a job is that costwise?
 
It all depends on the size of the existing rads.

You really need to get a thermometer to measure the temps each room is reaching with the doors closed after say two hours with the flow temp set at 70 C ( being the normal setting ).

Then compare with the outside temperature.

Say its 1 C outside and room reaches 11 C then the radiator is half of the required heat output to reach 21 C.

They are probably at least 30-40% undersized.

Rads might cost about £60 per 1000mm length for a single panel.

The larger ones might be able to be moved to smaller rooms.

Labour perhaps £90 each as pipework has to be modified to suit.

Do they have TRVs on the rads as required by building regs?

Tony
 
It all depends on the size of the existing rads.

You really need to get a thermometer to measure the temps each room is reaching with the doors closed after say two hours with the flow temp set at 70 C ( being the normal setting ).

Then compare with the outside temperature.

Say its 1 C outside and room reaches 11 C then the radiator is half of the required heat output to reach 21 C.

They are probably at least 30-40% undersized.

Rads might cost about £60 per 1000mm length for a single panel.

The larger ones might be able to be moved to smaller rooms.

Labour perhaps £90 each as pipework has to be modified to suit.

Do they have TRVs on the rads as required by building regs?

Tony

I will try to do the thermometer thing this weekend as it's apparently meant to be freezing again!

Yes, TRVs are on all rads.

OK, I've just had a closer look at all the rads and it looks like he's cheapened the job by going for single radiators instead of double! (Apart from the kitchen, which is a double, and as I said earlier, is the only room that's warm enough!)

So if these singles were all changed to doubles using the same size length and width wise but with a little deeper depth, would the pipework still need altering?
 

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