Re: {Disarmed} New Remote Controlled Thermostatic Electronic Radiator Valve

[Kevin Hawkins <yahoogroupskh@xxxxxxxxxxxxxx>]

Yes... not all condensing boilers modulate, many just fire on / off.

Also some still generate too much heat when most of the TRV's are
satisfied even at minimal modulation  which can lead to cycling .  I
think they can typically only reduce to about 30% of max output.   My
boiler was over specified and when trying to heat only the hot water
cylinder it can't modulate low enough,  i.e the coil can't dissipate the
minimum modulated output of the boiler.     Lee says he slightly
underspecified his boiler which creates greater flow/return temperature
differential which improves efficiency.  Although at full load  it might
struggle to maintain heat in all rooms or take slightly longer to warm
up, in practice I feel it's a much better approach as few homes have a
maximum demand for any significant period, particularly when zoned with
multiple thermostats.

K

On 17/08/2011 22:19, Wayne Harrison wrote:
> Hi Lee, Thanks for that - I think I get the idea.
>
> Is a condenser boiler a standard run of the mill job? Looking at ours
- funnily enough, 11 years old today, it really doesn't seem to do anything
special other than a pilot light being always there. When the heating comes
'on' (either by the thermostat control or just forcing it to be 'on') it
makes the same noises and seems to burn as 'hard' either way.
>
>
> Cheers
> Wayne.
>
>
>
>
> On 15 Aug 2011, at 23:29, Vargster wrote:
>
>> Wayne,
>>
>> The boiler tests the temperature of the returning water. I.e. the
water
>> leaves the boiler, travels around the house going through the
radiators and
>> returns to the boiler.  As the returning temp approaches the flow
>> temperature, the boiler modulates (turns down) the burner, putting
less heat
>> into the water. This 'saves' gas, but the efficiency drops because
the
>> condensing part of the boiler doesn't work when the returning
water temp is
>> too high.
>>
>> When your thermostat thinks the room is hot enough, it just shuts
the whole
>> boiler down. You should also have a timeclock/controller that tell
the
>> boiler to come on too...
>>
>> Lee
>>
>> On Mon, Aug 15, 2011 at 9:35 PM, Wayne
Harrison<Wayne@xxxxxxx>wrote:
>>
>>> Hi all,
>>> I might be having a real thick here (more than likely!)) - I'm
no plumber,
>>> not even allowed after the 'christmas eve incident' - i
digressâ??
>>>
>>> Our heating system has one central thermostat in the hallway
that governs
>>> if the boiler is active or not. There is also a timer to set
the thing to
>>> come on and go off at two times during the day or there is a
manual override
>>> to just turn it on or keep it off.
>>>
>>> When its running - its the single thermostat that actually
governs the
>>> heating. My question being - if we had these fitted to the
radiators do I
>>> need to just turn up the thermostat to its highest temperature
to
>>> effectively nail it on? If I do that - what stops the boiler
from just
>>> burning more fuel as it doesn't think its getting the house up
to
>>> temperature? Doesn't sound like a saving there to meâ??
but as I said - I'm no
>>> plumber - or heating expert :-)
>>>
>>> Thanks
>>> Wayne.
>>>
>>>
>>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>>
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