A few weeks ago British Gas serviced the boiler. Not my idea. Nice young
lady who left me a leak on the Magfilter.
Since the service we have noticed that the house takes a LOT longer to warm
up. Before the service the place was warm in a couple of hours. After the
service the house took about five hours to get warm - with the boiler
running of course. The rads were hot, but not as hot as before the service.
I suspected that she had turned the temperature on the heating side of the
boiler down, but was to lazy to check as the boiler is in the loft.
Today I had a look. From 3/4 she had turned the temp down to 1/2. She did
not tell me that she had done this. The temp setting had been on 3/4 since
the boiler was installed eight years ago.
I turned back up to 3/4 and the house was warm in no time, rads very hot.

Would I be correct in thinking that two hours running on 3/4 uses less gas
than five hours running on 1/2?
I never thought to take a meter reading.

On Monday, 22 January 2018 17:21:39 UTC, Mr Pounder Esquire wrote:
Would I be correct in thinking that two hours running on 3/4 uses less gas
than five hours running on 1/2?

Not necessarily; if it's a condensing boiler running on 1/2 may be more efficient.

Owain

On 22/01/2018 17:21, Mr Pounder Esquire wrote:
A few weeks ago British Gas serviced the boiler. Not my idea. Nice young
lady who left me a leak on the Magfilter.
Since the service we have noticed that the house takes a LOT longer to warm
up. Before the service the place was warm in a couple of hours. After the
service the house took about five hours to get warm - with the boiler
running of course. The rads were hot, but not as hot as before the service.
I suspected that she had turned the temperature on the heating side of the
boiler down, but was to lazy to check as the boiler is in the loft.
Today I had a look. From 3/4 she had turned the temp down to 1/2. She did
not tell me that she had done this. The temp setting had been on 3/4 since
the boiler was installed eight years ago.
I turned back up to 3/4 and the house was warm in no time, rads very hot.

Would I be correct in thinking that two hours running on 3/4 uses less gas
than five hours running on 1/2?

Do your turn the heating off after two hours normally?

In reality it depends on several factors... If its a condenser, then
they gain in efficiency as the return temperature falls. So just warm
enough to do the job will typically get best results. Most boilers these
days can adjust their output power to suit the load (modulation), but
raising the flow temp can also raise the minimum heat input to the
system - so on milder days may promote more cycling of the boiler. That
will also reduce efficiency a bit. (although on modern boilers its less
of a problem than on old systems without pump run on).

The ideal situation is the boiler just ticking over supplying heat at
the same rate the property is losing it - that will give good comfort
and efficiency. However the problem with that approach is on cold days
it will struggle to get the place work quickly. (tis why posh systems
use weather compensation)



--
Cheers,

John.

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| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
On 22/01/2018 17:21, Mr Pounder Esquire wrote:
A few weeks ago British Gas serviced the boiler. Not my idea. Nice
young lady who left me a leak on the Magfilter.
Since the service we have noticed that the house takes a LOT longer
to warm up. Before the service the place was warm in a couple of
hours. After the service the house took about five hours to get warm
- with the boiler running of course. The rads were hot, but not as
hot as before the service. I suspected that she had turned the
temperature on the heating side of the boiler down, but was to lazy
to check as the boiler is in the loft. Today I had a look. From 3/4 she
had turned the temp down to 1/2.
She did not tell me that she had done this. The temp setting had
been on 3/4 since the boiler was installed eight years ago.
I turned back up to 3/4 and the house was warm in no time, rads very
hot. Would I be correct in thinking that two hours running on 3/4 uses
less gas than five hours running on 1/2?

Do your turn the heating off after two hours normally?

Yes. It's the way we like to do it. Then maybe back on for an hour, this
several hours later. The house is very well insulated.

In reality it depends on several factors... If its a condenser, then
they gain in efficiency as the return temperature falls. So just warm
enough to do the job will typically get best results. Most boilers
these days can adjust their output power to suit the load
(modulation), but raising the flow temp can also raise the minimum
heat input to the system - so on milder days may promote more cycling
of the boiler. That will also reduce efficiency a bit. (although on
modern boilers its less of a problem than on old systems without pump
run on).
The ideal situation is the boiler just ticking over supplying heat at
the same rate the property is losing it - that will give good comfort
and efficiency. However the problem with that approach is on cold days
it will struggle to get the place work quickly. (tis why posh systems
use weather compensation)

Five hours to reach 22C?





/================================================== ===============\
Internode Ltd - http://www.internode.co.uk |
-----------------------------------------------------------------|
John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 22/01/2018 18:53, Mr Pounder Esquire wrote:
John Rumm wrote:
On 22/01/2018 17:21, Mr Pounder Esquire wrote:
A few weeks ago British Gas serviced the boiler. Not my idea. Nice
young lady who left me a leak on the Magfilter.
Since the service we have noticed that the house takes a LOT longer
to warm up. Before the service the place was warm in a couple of
hours. After the service the house took about five hours to get warm
- with the boiler running of course. The rads were hot, but not as
hot as before the service. I suspected that she had turned the
temperature on the heating side of the boiler down, but was to lazy
to check as the boiler is in the loft. Today I had a look. From 3/4 she
had turned the temp down to 1/2.
She did not tell me that she had done this. The temp setting had
been on 3/4 since the boiler was installed eight years ago.
I turned back up to 3/4 and the house was warm in no time, rads very
hot. Would I be correct in thinking that two hours running on 3/4 uses
less gas than five hours running on 1/2?

Do your turn the heating off after two hours normally?

Yes. It's the way we like to do it. Then maybe back on for an hour, this
several hours later. The house is very well insulated.

In reality it depends on several factors... If its a condenser, then
they gain in efficiency as the return temperature falls. So just warm
enough to do the job will typically get best results. Most boilers
these days can adjust their output power to suit the load
(modulation), but raising the flow temp can also raise the minimum
heat input to the system - so on milder days may promote more cycling
of the boiler. That will also reduce efficiency a bit. (although on
modern boilers its less of a problem than on old systems without pump
run on).
The ideal situation is the boiler just ticking over supplying heat at
the same rate the property is losing it - that will give good comfort
and efficiency. However the problem with that approach is on cold days
it will struggle to get the place work quickly. (tis why posh systems
use weather compensation)

Five hours to reach 22C?

Without knowing the flow temperature at the two settings it's not
possible to tell.

Why not have a room stat to set the desired temperature, and then leave
the boiler at 1/2 or even less?

Fredxx wrote:
On 22/01/2018 18:53, Mr Pounder Esquire wrote:
John Rumm wrote:
On 22/01/2018 17:21, Mr Pounder Esquire wrote:
A few weeks ago British Gas serviced the boiler. Not my idea. Nice
young lady who left me a leak on the Magfilter.
Since the service we have noticed that the house takes a LOT longer
to warm up. Before the service the place was warm in a couple of
hours. After the service the house took about five hours to get
warm - with the boiler running of course. The rads were hot, but
not as hot as before the service. I suspected that she had turned the
temperature on the heating side of the boiler down, but was to lazy
to check as the boiler is in the loft. Today I had a look. From
3/4 she had turned the temp down to 1/2.
She did not tell me that she had done this. The temp setting had
been on 3/4 since the boiler was installed eight years ago.
I turned back up to 3/4 and the house was warm in no time, rads
very hot. Would I be correct in thinking that two hours running on
3/4 uses less gas than five hours running on 1/2?

Do your turn the heating off after two hours normally?

Yes. It's the way we like to do it. Then maybe back on for an hour,
this several hours later. The house is very well insulated.

In reality it depends on several factors... If its a condenser, then
they gain in efficiency as the return temperature falls. So just
warm enough to do the job will typically get best results. Most
boilers these days can adjust their output power to suit the load
(modulation), but raising the flow temp can also raise the minimum
heat input to the system - so on milder days may promote more
cycling of the boiler. That will also reduce efficiency a bit.
(although on modern boilers its less of a problem than on old
systems without pump run on).
The ideal situation is the boiler just ticking over supplying heat
at the same rate the property is losing it - that will give good
comfort and efficiency. However the problem with that approach is
on cold days it will struggle to get the place work quickly. (tis
why posh systems use weather compensation)

Five hours to reach 22C?

Without knowing the flow temperature at the two settings it's not
possible to tell.

Why not have a room stat to set the desired temperature, and then
leave the boiler at 1/2 or even less?


I have no means of measuring the flow temp.
Condensing boiler.
We like to sleep in a cool bedroom, say 18C or cooler.
The way she set the boiler took 5 hours to warm the house by 4 degrees.
Setting to 18C at bed time would still take 5 hours to reach 22C.