Currently I don't have a central heating system.
I want a system which allows me to control each radiator separately.
This will then allow me to only have rooms heated when they are likely
to be occupied and to properly control the temperature with wall
thermostats.
Rather than employ 2 port motorised valves I thought about trying a
different system of control.
What would happen if a standard thermostically controlled radiator
valve was set to full temperature and then a resistor placed in the
vicinity to facilitate temperature control. By applying a voltage to
the resistor it would heat up and, hopefully, cause the valve to
close.
Has anyone tried this method of control?
If so:-
1. With what type of thermostically controlled valve?
2. What power dissipation was necessary in the resistor to achieve the
necessary control?
3. Where, precisely, was the resistor placed?
4. What sort of hysterysis was evident?

(I am aware that at one time capilliary/bulb systems were used but
having not found them on appropriate web sites I assume that they are
no longer used. I need a system which employs current proprietary
parts.)






Remove 'no_spam_' from email address.

Why dont you just use a standard thermostatic valve on each radiator???

jim

In message .com, Jim
writes
Why dont you just use a standard thermostatic valve on each radiator???

I think he wants a remote/centrally or automatically timsd operated
system (well I assume so)

might find the Honeywell CM-Zone system of interest?

http://www.cm-zone.com/
--
Chris French

In article ,
Brian A writes:
Currently I don't have a central heating system.
I want a system which allows me to control each radiator separately.
This will then allow me to only have rooms heated when they are likely
to be occupied and to properly control the temperature with wall
thermostats.
Rather than employ 2 port motorised valves I thought about trying a
different system of control.
What would happen if a standard thermostically controlled radiator
valve was set to full temperature and then a resistor placed in the
vicinity to facilitate temperature control. By applying a voltage to
the resistor it would heat up and, hopefully, cause the valve to
close.
Has anyone tried this method of control?

I did it with a Grugasar gas wall heater which had a capilliary/bulb
providing modulating/proportional control, but no timeswitch or remote
control capability built in.

I taped 3 resistors to it. I had originally intended to drive these
directly from the alarm/home-automation system, but found I needed
more power than I wanted to drain from its battery backed supply,
so I used a wall-wart to power it, controlled by the HA system.

You can callibrate it by driving the resistors at a certain power,
and measuring the corresponding setback in room temperature. This
then scales linearly to increase or decrease the setback temperature
required. Then you set the thermostat (TRV in your case) to the
normal room temperature, and drive the resistors to create the
appropriate setback. I had two setback levels -- one for night
time of a few degrees setback, and one for frost/damp protection.

One thing is I'm not conviced by the accurancy of TRV's. The
Drugasar I had would maintain the room temperature to an accuracy
of 0.1C (it had a very long bulb, which made it both accurate and
responsive), but I don't think TRVs come close to that, which might
make the calibration difficult, and the final result a bit more hit
and miss.

I vaguely recall finding a web page somewhere showing how someone
had done this with TRVs, so you could try searching that out.

--
Andrew Gabriel

"Brian A" wrote in message
...
Currently I don't have a central heating system.
I want a system which allows me to control each radiator separately.
This will then allow me to only have rooms heated when they are likely
to be occupied and to properly control the temperature with wall
thermostats.
Rather than employ 2 port motorised valves I thought about trying a
different system of control.
What would happen if a standard thermostically controlled radiator
valve was set to full temperature and then a resistor placed in the
vicinity to facilitate temperature control. By applying a voltage to
the resistor it would heat up and, hopefully, cause the valve to
close.
Has anyone tried this method of control?
snip

You've invented the boneless sausage!

Google this group for much earlier discussion about home-made and
commercial versions.

I bought Sauter actuators, sold as Prefect 9500 Wet Radiator Valve
Drives from Prefect Controls (www.prefectcontrols.com) for about 23 quid
each. Still waiting for the tuit for my own house, but I installed them
successfully in my mother's place. The ones I bought don't have
auxiliary switches, so I'll need to use the changeover switching of my
roomstats for boiler control and have the actuators in their
normally-open mode.

For a completely new installation in my son's house, I went for the
manifold principle, with a valve farm of conventional motorised valves -
except that to minimise the initial cost they're all just plain lengths
of pipe at present. Pipe sizes to individual radiators depend on length
and required flows - only one needed 15mm in our case - and there are a
couple of places where returns are commoned. As funds permit, motorised
valves and programmable room stats will be added with no disturbance to
floorboards and pipe runs.



--
Kevin Poole
**Use current month and year to reply (e.g. )***
Car Transport by Tiltbed Trailer - based near Derby

"Autolycus" wrote in message
...

"Brian A" wrote in message
...
Currently I don't have a central heating system.
I want a system which allows me to control each radiator separately.
This will then allow me to only have rooms heated when they are likely
to be occupied and to properly control the temperature with wall
thermostats.
Rather than employ 2 port motorised valves I thought about trying a
different system of control.
What would happen if a standard thermostically controlled radiator
valve was set to full temperature and then a resistor placed in the
vicinity to facilitate temperature control. By applying a voltage to
the resistor it would heat up and, hopefully, cause the valve to
close.
Has anyone tried this method of control?
snip

You've invented the boneless sausage!

Google this group for much earlier discussion about home-made and
commercial versions.

I bought Sauter actuators, sold as Prefect 9500 Wet Radiator Valve
Drives from Prefect Controls (www.prefectcontrols.com) for about 23 quid
each. Still waiting for the tuit for my own house, but I installed them
successfully in my mother's place. The ones I bought don't have
auxiliary switches, so I'll need to use the changeover switching of my
roomstats for boiler control and have the actuators in their
normally-open mode.

For a completely new installation in my son's house, I went for the
manifold principle, with a valve farm of conventional motorised valves -
except that to minimise the initial cost they're all just plain lengths
of pipe at present. Pipe sizes to individual radiators depend on length
and required flows - only one needed 15mm in our case - and there are a
couple of places where returns are commoned. As funds permit, motorised
valves and programmable room stats will be added with no disturbance to
floorboards and pipe runs.

This is probably the cheapest method, running all stat and zone valves
cables back to a junction box. The problem is it takes up space. But is does
give more precise temp control of rooms and time zone can be selected from
just one to every room being a zone. Using the sauter valves does the same,
but a stats are required about the house, controlling each chosen zone.

When constructing a manifold install good quality full bore isolation valves
to isolate the battery of zone valves on the manifold, and use a Grundfoss
Alpha variable speed pressure sensing pump.

"chris French" wrote in message
...
snip

might find the Honeywell CM-Zone system of interest?

http://www.cm-zone.com/

That has got to be one of the worst web sites going, it's quicker to
watch paint dry!

'Design' over accessible content... :~(

Rather than employ 2 port motorised valves I thought about trying a
different system of control.
What would happen if a standard thermostically controlled radiator
valve was set to full temperature and then a resistor placed in the
vicinity to facilitate temperature control.

You can buy them ready made (obviously not from B&Q!). However, you can also
get motorised heads, which are more reliable, if a little more expensive. I
can't remember the supplier, unfortunately.

Christian.

":::Jerry::::" wrote in message
eenews.net...

"chris French" wrote in message
...
snip

might find the Honeywell CM-Zone system of interest?

http://www.cm-zone.com/

That has got to be one of the worst web sites going, it's quicker to
watch paint dry!

'Design' over accessible content... :~(


You must have gone to a different site.
I was looking at the installer diagrams after about three clicks.

In message , Brian A
writes
Currently I don't have a central heating system.
I want a system which allows me to control each radiator separately.
This will then allow me to only have rooms heated when they are likely
to be occupied and to properly control the temperature with wall
thermostats.
Rather than employ 2 port motorised valves I thought about trying a
different system of control.
What would happen if a standard thermostically controlled radiator
valve was set to full temperature and then a resistor placed in the
vicinity to facilitate temperature control. By applying a voltage to
the resistor it would heat up and, hopefully, cause the valve to
close.
Has anyone tried this method of control?
If so:-
1. With what type of thermostically controlled valve?
2. What power dissipation was necessary in the resistor to achieve the
necessary control?
3. Where, precisely, was the resistor placed?
4. What sort of hysterysis was evident?

(I am aware that at one time capilliary/bulb systems were used but
having not found them on appropriate web sites I assume that they are
no longer used. I need a system which employs current proprietary
parts.)

Yeah - this has been discussed numerous times before

but ... why not just put TRVs on each radiator, unless you are after a
significantly more sophisticated form of control

--
geoff

"raden" wrote in message
...
snip

but ... why not just put TRVs on each radiator, unless you are
after a
significantly more sophisticated form of control


Do you know of a make of TRV that actually works correctly, all the
ones I've ever come across seem to fail down in one department of the
other?

It seems strange to be measuring the 'room' temperature so low down
and so close to the heat source....

Do you know of a make of TRV that actually works correctly, all the
ones I've ever come across seem to fail down in one department of the
other?

My ones actually work very well. It helps when they have a limited
temperature mode. I limited mine with a pin to 22C, which means that
uninformed people can't fiddle with them because they're cold and the
heating has only just come on.

My mum's house is all other the shop with temperature. This is largely
because she turns them up when she's cold and down when she's hot, rather
than just putting them on a sensible setting and leaving them alone.

It seems strange to be measuring the 'room' temperature so low down
and so close to the heat source....

Although not ideal, it does actually work. It is helped by the convection
currents that the heating sets up. The TRV (if mounted low down) senses the
temperature of the cold convection air sucked in by the rising hot air.

Christian.

In message ws.net,
":::Jerry::::" writes

"raden" wrote in message
...
snip

but ... why not just put TRVs on each radiator, unless you are
after a
significantly more sophisticated form of control


Do you know of a make of TRV that actually works correctly, all the
ones I've ever come across seem to fail down in one department of the
other?


I was always more than happy with the Drayton TRV4's I fitted in the
last house (others here have also expressed similar comments) I'll
replace those in this house which don't work with the same.

It seems strange to be measuring the 'room' temperature so low down
and so close to the heat source....

because it's convienient/eassier and works well enough? you can get
remote sensors for those situations when it doesn't.
--
Chris French

In article ws.net,
:::Jerry:::: wrote:
Do you know of a make of TRV that actually works correctly, all the
ones I've ever come across seem to fail down in one department of the
other?

It seems strange to be measuring the 'room' temperature so low down
and so close to the heat source....

In theory they work by the fact that air will circulate round them by
convection. Mounting them horizontally seems to help with the radiated
heat part.

--
*Your kid may be an honours student, but you're still an idiot.

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

In article ,
Christian McArdle wrote:
My mum's house is all other the shop with temperature. This is
largely because she turns them up when she's cold and down when
she's hot, rather than just putting them on a sensible setting
and leaving them alone.

I made the mistake of putting a CM67 in my mum's place. Nice and
sensibly it's in the living room where she spends most of her time.
Then when I visit it's "I had to put the electric fire because the
radiators have gone cold again". Of course they're cold because the
heat of the electric fire has turned off the CM67. sigh

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.10 released 4 April 2005]

"Tony Bryer" wrote in message
...
In article ,
Christian McArdle wrote:
My mum's house is all other the shop with temperature. This is
largely because she turns them up when she's cold and down when
she's hot, rather than just putting them on a sensible setting
and leaving them alone.

I made the mistake of putting a CM67 in my mum's place. Nice and
sensibly it's in the living room where she spends most of her time.
Then when I visit it's "I had to put the electric fire because the
radiators have gone cold again". Of course they're cold because the
heat of the electric fire has turned off the CM67. sigh


How old is she?
Older people need temperatures in the 22-26+C or they feel cold.
Its no good setting the stat to 21C and expecting them to not use the fire.

In article ,
Dennis@home wrote:
How old is she?
Older people need temperatures in the 22-26+C or they feel cold.
Its no good setting the stat to 21C and expecting them to not use
the fire.

I've got it a 22 in the morning and evening. My mother is an otherwise
intelligent woman who fails to understand that when a thermostat's set
temperature is reached the boiler is switched off. What she really
needs is a weather compensated boiler that runs 24 hours per day
making the flow temp warmer or cooler as necessary.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.10 released 4 April 2005]

Tony Bryer wrote:
In article ,
Dennis@home wrote:

How old is she?
Older people need temperatures in the 22-26+C or they feel cold.
Its no good setting the stat to 21C and expecting them to not use
the fire.


I've got it a 22 in the morning and evening. My mother is an otherwise
intelligent woman who fails to understand that when a thermostat's set
temperature is reached the boiler is switched off. What she really
needs is a weather compensated boiler that runs 24 hours per day
making the flow temp warmer or cooler as necessary.


I work in an office full of people like that. Air con set to lowest
setting so it blows cold air until the office is freezing, then they put
it to highest setting so it blows warm air until roasting. The cylce
repeats.

"Tony Bryer" wrote in message
...
In article ,
Dennis@home wrote:
How old is she?
Older people need temperatures in the 22-26+C or they feel cold.
Its no good setting the stat to 21C and expecting them to not use
the fire.

I've got it a 22 in the morning and evening. My mother is an otherwise
intelligent woman who fails to understand that when a thermostat's set
temperature is reached the boiler is switched off. What she really
needs is a weather compensated boiler that runs 24 hours per day
making the flow temp warmer or cooler as necessary.

Don't blame the user because you have installed a control system they can't
use (are you a programmer?).
Try a two button system one which says "I am cold" and one that says "I am
hot".
Use that to control the thermostat in smallish increments.

Dump the radiators as they react too slowly (try a fan heater/ skirting
heating).
This is why people keep changing the stats.. the systems are too slow to
provide feedback.
Probably the main drawback of hot water CH.
The solution is big boilers, less water or a big stick.

On Fri, 21 Oct 2005 13:05:17 +0100, a particular chimpanzee named Tony
Bryer randomly hit the keyboard and produced:

Then when I visit it's "I had to put the electric fire because the
radiators have gone cold again". Of course they're cold because the
heat of the electric fire has turned off the CM67. sigh

Does anyone's mum know how to use central heating controls ;-)
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"

On Fri, 21 Oct 2005 19:01:01 +0100, Hugo Nebula abuse@localhost
scrawled:

Does anyone's mum know how to use central heating controls ;-)

Mine was pretty good with the old controls on the Y plan. The new TR2
room temperature sensor on the Worcester combi confuses her a bit,
especially when I go into the setback and comfort tekmperatures and
different modes of 'on'.
--
Stuart @ SJW Electrical

Please Reply to group

In article ,
Owain wrote:
Hugo Nebula wrote:
Does anyone's mum know how to use central heating controls ;-)

Mine's just about worked out light switches

You're lucky. Mine expected rotary switches for lights same as gas.

--
*Everybody lies, but it doesn't matter since nobody listens.

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