I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it is
possible to leave the central heating timer switched on all the time and
just to control boiler activity using one of these. Horstmann or Danfoss,
any comments as to which is better?

In article , Grumps
writes
I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it is
possible to leave the central heating timer switched on all the time and
just to control boiler activity using one of these. Horstmann or Danfoss,
any comments as to which is better?



We've got 2 honeybum CM67 which is a programmable thermostat and the
boiler is controlled by those . Their progged for day/ time/ and temp
and the only thing we do with them is change the time twice a year, and
change the batteries whenever.

One downstairs on one circuit, and one up stairs on 't other. A separate
tank stat controls the water with a timer to stop the bloody thing
firing off the boiler in the middle of the night.

Works fine, and we have rad stats on some rads in lesser used rooms....
--
Tony Sayer

On Fri, 23 Sep 2005 07:33:47 +0100, "Grumps"
wrote:

| I assume that with a progammable thermostat (eg.
| http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
| http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it is
| possible to leave the central heating timer switched on all the time and
| just to control boiler activity using one of these. Horstmann or Danfoss,
| any comments as to which is better?

Especially are they easy to program?
I have to program one, not the above, which is an absolute *swine* to
program.

--
Dave Fawthrop dave hyphenologist co uk
"Intelligent Design?" my knees say *not*.
"Intelligent Design?" my back says *not*.

In an earlier contribution to this discussion,
Grumps wrote:

I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it is
possible to leave the central heating timer switched on all the time
and just to control boiler activity using one of these. Horstmann or
Danfoss, any comments as to which is better?

Yes, set CH on the original timer to constant and use the timing function in
the programmable stat to do the actual timing. [The original timer can still
time the hot water, of course]

The Danfoss is a bit more expensive but allows for 6 on-off events per 24
hours - which is useful. I don't know how many the Horstmann does - it
doesn't say.

Both do 5/2 day programmes so that you can do something different at the
weekend. If your life/work pattern is more complicated than that, you may be
better off with a stat which allows a different programme for each day of
the week - such as the Honeywell CM67. The CM67 also has an 'optimum start'
option whereby you tell it the time at which you need the house to be up to
temperature, and it decides when to turn the heating on. More expensive
still, of course, (about 45 quid from RKM Controls) but worth it if you want
the extra features.
http://www.heatingcontrolsonline.co....products_id=67
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

In article ,
Dave Fawthrop wrote:
I have to program one, not the above, which is an absolute *swine* to
program.

I've got a Horstmann and would agree with that. Perhaps a good idea to
stop people fiddling, but I've got to get out the instructions to change
the time for BST etc.

--
*Thank you. We're all refreshed and challenged by your unique point of view

Dave Plowman London SW
To e-mail, change noise into sound.

In message , Set Square
writes
The CM67 also has an 'optimum start'
option whereby you tell it the time at which you need the house to be up to
temperature, and it decides when to turn the heating on

How does it work this out? does it 'learn' in someway, or is it som e
sort of preset - if it's 5 c then turn on 1 hour before sort of thing?

--
Chris French

On Fri, 23 Sep 2005 07:33:47 +0100, "Grumps"
wrote:

I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it is
possible to leave the central heating timer switched on all the time and
just to control boiler activity using one of these. Horstmann or Danfoss,
any comments as to which is better?

We have a Grasslin Towerchron QE2 and it's a nightmare to program.

sponix

Grumps wrote:
I assume that with a progammable thermostat

IMHE, Spend the extra money and get the Landis & Gyr programmable. Dead
easy to set and a nice little temp graph display of what you've set it
to. They are worth having

On Fri, 23 Sep 2005 10:41:07 +0100, "Dave Plowman (News)"
wrote:

| In article ,
| Dave Fawthrop wrote:
| I have to program one, not the above, which is an absolute *swine* to
| program.
|
| I've got a Horstmann and would agree with that. Perhaps a good idea to
| stop people fiddling, but I've got to get out the instructions to change
| the time for BST etc.

I have a copy of the instructions beside the d*mn programmer, so that at
least *I* can program it.

A bit of packing tape does *not* stop people fiddling.

--
Dave Fawthrop dave hyphenologist co uk
The London suicide bombers killed innocent commuters.
Animal rights terrorists and activists kill innocent patients.

"Grumps" wrote in message
...
I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it is
possible to leave the central heating timer switched on all the time and
just to control boiler activity using one of these. Horstmann or Danfoss,
any comments as to which is better?



We've had the Horstmann programmer for 3 years.

It's 2 wire, & is battery powered by 2 AAA batteries.

The batteries typically last only a year (longer if you fir Duracells), and
to be honest I'd prefer a 3 wire, mains powered programmer, as it's a pain
in the butt when this unit stops operating due to flat batteries when you
don't have any spares at hand, resulting in no heating !.

As far as functinality goes:

(Very easy to program, without reading the manual.)

You can set 4 independent temperatures values for week days (i.e., Mon to
Fri) inclusive.

You can set 4 temperatures values for day 6 (Saturday)

You can set 4 temperatures values for day 6 (Sunday)

And, yes, you can leave your timer switched on all the time using this
programmer to control your heating.

I've no idea about the Danfoss programmer though...

woodglass wrote:
"Grumps" wrote in message
...
I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it
is possible to leave the central heating timer switched on all the
time and just to control boiler activity using one of these.
Horstmann or Danfoss, any comments as to which is better?



We've had the Horstmann programmer for 3 years.

It's 2 wire, & is battery powered by 2 AAA batteries.

The batteries typically last only a year (longer if you fir
Duracells), and to be honest I'd prefer a 3 wire, mains powered
programmer, as it's a pain in the butt when this unit stops operating
due to flat batteries when you don't have any spares at hand,
resulting in no heating !.

As far as functinality goes:

(Very easy to program, without reading the manual.)

You can set 4 independent temperatures values for week days (i.e.,
Mon to Fri) inclusive.

You can set 4 temperatures values for day 6 (Saturday)

You can set 4 temperatures values for day 6 (Sunday)

And, yes, you can leave your timer switched on all the time using this
programmer to control your heating.

I've no idea about the Danfoss programmer though...

Thanks to all for your replies.

In an earlier contribution to this discussion,
chris French wrote:

In message , Set Square
writes
The CM67 also has an 'optimum start'
option whereby you tell it the time at which you need the house to
be up to temperature, and it decides when to turn the heating on

How does it work this out? does it 'learn' in someway, or is it som e
sort of preset - if it's 5 c then turn on 1 hour before sort of thing?

AIUI, it uses its previous experience to 'remember' the rate of temperature
rise when the heating is running - and so works out how long it needs to run
for to achieve the desired temperature. It works reasonably well - and errs
on the side of starting too soon rather than too late - but still saves
energy on milder days by not starting the heating unnecessarily early.

It also goes into a proportional control mode when it gets near to the
setpoint - which helps to avoid overshoot - again saving energy.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

"Dave Plowman (News)" in a haze of senile flatulence
wrote in message ...
In article ,
Dave Fawthrop wrote:
I have to program one, not the above, which is an absolute *swine* to
program.

I've got a Horstmann and would agree with that.

That is expected from the likes of you.

On Fri, 23 Sep 2005 07:33:47 +0100, Grumps wrote:

I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860#
or http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it
is possible to leave the central heating timer switched on all the time
and just to control boiler activity using one of these. Horstmann or
Danfoss, any comments as to which is better?

The first is truly awful. 2xAAA batts only last 18 months. Hard to
program. Does not show target temps. No holiday mode (i.e. total override
until further notice but still leaving a low temperature setting against
freezing). The last draw back is absolute in my book.

The second I've not tried.

My choice although rather large is #12157
http://www.screwfix.com/app/sfd/cat/...2157&ts=55860#

It is a little overly complex with the potential for every day different
but defaults to each day the same. 3xAA batts last at lest 5 years.
Not as complex as the 'set back' and 'external compensating' models though.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

On Fri, 23 Sep 2005 10:06:48 GMT, (s--p--o--n--i--x)
scrawled:

We have a Grasslin Towerchron QE2 and it's a nightmare to program.

I have a look of bemusement. Peice of cake with your eyes closed.
--
Stuart @ SJW Electrical

Please Reply to group

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
chris French wrote:

In message , Set Square
writes
The CM67 also has an 'optimum start'
option whereby you tell it the time at which you need the house to
be up to temperature, and it decides when to turn the heating on

How does it work this out? does it 'learn' in someway, or is it som e
sort of preset - if it's 5 c then turn on 1 hour before sort of thing?

AIUI, it uses its previous experience to 'remember' the rate of
temperature
rise when the heating is running

It is referred to as "self-adaptive".