Programmable thermostat - Honeywell CM67
Menno
Hi,
I just bought the CM67 RF thermostat (after seeing it recommended on the
group), and after unpacking realise there is no options on it for the hot
water. I have a hot water cylinder, so how should I control the water?
Currently I have a basic controller which allows "hot water" or "hot water +
central heating", and two on/off time-points. There is no thermostat.
Do I need to keep the controller and connect the CM67 in series?
Or can I buy some other thermostat which also can program the water settings?
Does that exist?
Any help appreciated,
Thanks,
Menno.
Sent via Deja.com http://www.deja.com/
Before you buy.
Tim Riglar
roomstat - it doesn't replace the controller. I set the CH to "constant" on
the controller and let the programmable roomstat control the temperature. HW
is still set to come on twice a day.
You only need to replace the roomstat, which may be two or three wire - the
replacement will only need two of them, ISTR.
HTH
Tim
"Menno" <jan...@my-deja.com> wrote in message
news:8uju76$7q9$1...@nnrp1.deja.com...
Menno
"Tim Riglar" <tim.r...@ntlworld.com> wrote:
> The CM67 thermostat, for all it's clever features, is only a fancy
> roomstat - it doesn't replace the controller. I set the CH to
Tim,
Are there any other models that do replace the controller? Would be nice to
have the same control over the water heating. But I guess I could live with
the old controller.
> You only need to replace the roomstat, which may be two or three wire
Ah this is it, there is no roomstat at the moment( At the moment I have to
keep switching it on/off when I get to cold/hot! )
Do I just hook up the CM67 receiver box in series with the current
controller? Or is it more complex? Couldnt find anything in the faq.
Thanks,
Menno
Menno
forces the HW on if the CH is on, so it would mean the HW is on all the time.
Is there a way round this?
Thanks,
Menno
In article <IgfP5.4345$f12....@news2-win.server.ntlworld.com>,
"Tim Riglar" <tim.r...@ntlworld.com> wrote:
> The CM67 thermostat, for all it's clever features, is only a fancy
> roomstat - it doesn't replace the controller. I set the CH to "constant" on
> the controller and let the programmable roomstat control the temperature. HW
> is still set to come on twice a day.
>
> You only need to replace the roomstat, which may be two or three wire - the
> replacement will only need two of them, ISTR.
>
> HTH
>
> Tim
>
> "Menno" <jan...@my-deja.com> wrote in message
> news:8uju76$7q9$1...@nnrp1.deja.com...
> >
> >
> > Hi,
> >
> > I just bought the CM67 RF thermostat (after seeing it recommended on the
> > group), and after unpacking realise there is no options on it for the hot
> > water. I have a hot water cylinder, so how should I control the water?
> >
> > Currently I have a basic controller which allows "hot water" or "hot water
> +
> > central heating", and two on/off time-points. There is no thermostat.
> >
> > Do I need to keep the controller and connect the CM67 in series?
> >
> > Or can I buy some other thermostat which also can program the water
> settings?
> > Does that exist?
> >
> > Any help appreciated,
> > Thanks,
> > Menno.
> >
> >
Tim Riglar
I have to admit to not being a central heating expert (beyond extensive
DIY), but this seems to be an odd setup. How old is it, I wonder? The
"normal" arrangement is that separate thermostats for the central heating
and the hot water control isolator valves which direct the water flow to the
correct circuit. I guess I see where you are coming from - wire the "time"
and "temperature" switches in series - but I don't think that's going to
work. I need to find the circuit diagram which I used when I rewired my
central heating. If I do I'll repost with a better answer.
Central Heating wiring isn't "complex", per se, but it ain't trivial either!
You would definitely need a good circuit diagram showing how all the bits
connect together.
Hopefully someone else may post with an opinion on CH without a roomstat!
Regards
Tim
"Menno" <jan...@my-deja.com> wrote in message
news:8uk300$b9o$1...@nnrp1.deja.com...
> In article <IgfP5.4345$f12....@news2-win.server.ntlworld.com>,
> "Tim Riglar" <tim.r...@ntlworld.com> wrote:
> > The CM67 thermostat, for all it's clever features, is only a fancy
> > roomstat - it doesn't replace the controller. I set the CH to
>
> Tim,
>
> Are there any other models that do replace the controller? Would be nice
to
> have the same control over the water heating. But I guess I could live
with
> the old controller.
>
> > You only need to replace the roomstat, which may be two or three wire
>
> Ah this is it, there is no roomstat at the moment( At the moment I have to
> keep switching it on/off when I get to cold/hot! )
>
> Do I just hook up the CM67 receiver box in series with the current
> controller? Or is it more complex? Couldnt find anything in the faq.
>
> Thanks,
> Menno
>
>
Dave Liquorice
> Are there any other models that do replace the controller?
Danfoss do a combine programmable room thermostat and time control for the
HW. The TP9 in my 1998 brochure (thinks need to get new brochures I haven't
anything on the CM67...)
> Would be nice to have the same control over the water heating.
What do you mean by same control? Do you mean HW temperature? That is not
really required if you have a tank stat and motorised valve controlled by it
(slightly simplyfied description).
> Ah this is it, there is no roomstat at the moment( At the moment I have to
> keep switching it on/off when I get to cold/hot! )
Ah! Be prepared for a big jump in your fuel bill. When the time switch broke
on my flats system I was very slow at replacing it. The next gas bill
arrived about half the size of the previous one. I never bothered replacing
the timer just switched the CH and/or HW on as I required it. Both where
under thermostat control and the HW tank was well lagged an stayed hot
enough to be useable for washing >24hrs. No more timed top ups of heat to
the HW that weren't really required and it would reheat from cold in 20mins
anyway.
> Do I just hook up the CM67 receiver box in series with the current
> controller?
If the CM67 does all the bells and whistles that a programmer does as well
as the temperature control side. Disconect the CH wiring from the current
timer (leaving that to do HW only) and use the CM67 to fully control the CH
on it's own.
How you go about the physical wiring depends very much on how your current
system is configured both electricaly and plumbing wise. I'd seriously think
about adding a tank stat if you don't have one, they are very cheap (£20)
and could concievably save that in fuel within a year.
--
Cheers new...@howhill.com
Dave. Remove "spam" for valid email.
Menno
Tim and Dave,
Thanks for your replies, they have helped my figure out what's going on (I
think!). After studying all the pipes and wires in my system, it looks like
it is has gravity HW, and pumped CH. There is no motorised valve. The current
controller switches either the boiler on only, thus providing HW, or it
switches the boiler on and the pump, thus providing HW and CH. And I think
the boiler stat decides when to stop heating the cylinder water.
So I guess I could just wire the programmable thermostat in series with the
CH signal from the controller to the pump. The downside is that I would have
to leave the current controller always set to on for both CH and HW, so that
the programmable thermostat can control the CH (apart from when I go on
holiday or something I would have to switch it all off).
But now I would always have HW on. And as you both said this is not a problem
if I get a tank/cylinder stat, which will stop the boiler from cycling and
toping up the cylinder.
Does this make sense, or is there a better way to do this? Would adding a
valve to allow independent CH be better? Is it more efficient to keep the
cylinder at a certain temperature by having the HW controlled by a tank stat,
or timed, allowing it to cool and then reheat?
Thanks,
Menno
In article <nyyfbegfubjuvyypb...@snail.howhill.network>,
"Dave Liquorice" <new...@howhill.com> wrote:
> On Sat, 11 Nov 2000 18:26:13 GMT, Menno wrote:
>
> > Are there any other models that do replace the controller?
>
> Danfoss do a combine programmable room thermostat and time control for t=
> he
> HW. The TP9 in my 1998 brochure (thinks need to get new brochures I have=
> n't
> anything on the CM67...)
>
> > Would be nice to have the same control over the water heating.
>
> What do you mean by same control? Do you mean HW temperature? That is no=
> t
> really required if you have a tank stat and motorised valve controlled b=
> y it
> (slightly simplyfied description).
>
> > Ah this is it, there is no roomstat at the moment( At the moment I hav=
> e to
> > keep switching it on/off when I get to cold/hot! )
>
> Ah! Be prepared for a big jump in your fuel bill. When the time switch b=
> roke
> on my flats system I was very slow at replacing it. The next gas bill
> arrived about half the size of the previous one. I never bothered replac=
> ing
> the timer just switched the CH and/or HW on as I required it. Both where=
>
> under thermostat control and the HW tank was well lagged an stayed hot
> enough to be useable for washing >24hrs. No more timed top ups of heat t=
> o
> the HW that weren't really required and it would reheat from cold in 20m=
> ins
> anyway.
>
> > Do I just hook up the CM67 receiver box in series with the current
> > controller?
>
> If the CM67 does all the bells and whistles that a programmer does as we=
> ll
> as the temperature control side. Disconect the CH wiring from the curren=
> t
> timer (leaving that to do HW only) and use the CM67 to fully control the=
> CH
> on it's own.
>
> How you go about the physical wiring depends very much on how your curre=
> nt
> system is configured both electricaly and plumbing wise. I'd seriously t=
> hink
> about adding a tank stat if you don't have one, they are very cheap (=A3=
> 20)
> and could concievably save that in fuel within a year.
>
> --
> Cheers new...@howhill.com
> Dave. Remove "spam" for valid email.
>
>
Dave Liquorice
> it is has gravity HW, and pumped CH. There is no motorised valve. The
> current controller switches either the boiler on only, thus providing HW,
> or it switches the boiler on and the pump, thus providing HW and CH. And I
> think the boiler stat decides when to stop heating the cylinder water.
Fairly common set up in older places. The use of the boiler stat to control
the HW temperature is none optimum. The radiators really need to operate at
a temperature that produces HW far to hot to be safe. I consider the
radiators should be at 80C and the HW at 60C absolute maximum.
> So I guess I could just wire the programmable thermostat in series with
> the CH signal from the controller to the pump.
I think that is your only option. Bung 'em in paralell the heating comes on
(the pump is powered) when the HW only switches as you have to connect the
pump and boiler lives together so that the stat will turn both on.
> The downside is that I would have to leave the current controller always
> set to on for both CH and HW, so that the programmable thermostat can
> control the CH...
Well isn't that the way it works currently? Either you have HW only or HW &
CH. All you are adding is a temprature controlled switch in the pump
circuit. In the summer just switch it to HW only so that even if the stat
wants to heat it has no power to feed to the pump.
I don't have data on the CM67 (nothing useful on www.honeywell.com/uk)
unlike the Danfoss site which has data sheets, user and installation
instructions in .PDF format available for all their products, I digress. If
the CM67 is a battery powered relay then it doesn't need mains to maintain
the program so removing the mains from it as mentioned above for summer use
is not a problem.
> Is it more efficient to keep the cylinder at a certain temperature by
> having the HW controlled by a tank stat, or timed, allowing it to cool and
> then reheat?
Depends on how much HW you use and how well lagged you HW tank is. Cue story
about broken time switch and 50% reduction in gas bill due to manually
heating only when required as against on a timeswitch with tank stat
heating. The tank would stay useably hot with normal (non bath!) useage for
>24hrs.
Ed Sirett
>Just after I posted my reply I also realised that because my controller
>forces the HW on if the CH is on, so it would mean the HW is on all the
time.
>
>Is there a way round this?
>
>Thanks,
>Menno
>
system then you are going to need to do some plumbing. Read the FAQ to
get an idea of the various different systems and start to think about
what you need to alter the system, you'll also get the advantage of a
more consistant HW temperature.
You'll need to consider adding motorized valve(s) and cylinder
thermostat;
also you need to make sure you still have an unblokced route from the
boiler to the expansion pipe over the header tank.
Ed Sirett
Property Maintainer - North London.
ian_c...@my-deja.com
To fully use the CM67 without confusing yourself (and perhaps future
occupants) about what switches need to be where on the CM67 and old
programmer you should really get your system sorted out for what is
commonly called C-plan and _not_ run the CM67 from the CH channel on the
old programmer.
You'd need to adjust the C-plan wiring slightly since you have separate
HW and CH timers, but it isn't difficult once you've figured out what's
what.
Putting thermostat on the HW cylinder and a 2-port zone valve in the
gravity HW loop would give you independent control of CH and HW, and
control the HW temperature throughout the year.
Hopefully the gravity HW is via 28mm pipework, since valves of this size
have wires that are needed for C-plan but smaller sizes don't.
Finally, you might consider using the CM67 for some parts of the house
and the old CH channel for other parts if the occupancy patterns are
different enough that you'd only want to heat part of the house for part
of the day. This would need more valves and wiring changes though.
HTH
IanC
ian_c...@my-deja.com
Tim Riglar wrote:
>
> The CM67 thermostat, for all it's clever features, is only a fancy
> roomstat - it doesn't replace the controller.
Hi Tim
Although I don't have one I belive it does replace the controller.
Usually the timing and temperature switching are in separate boxes, this
being the programmer and simple room stat. These programable thermostats
combine these into a single box, and take advantage of the integration
to allow much more detailed programming.
> I set the CH to "constant" on
> the controller and let the programmable roomstat control the temperature.
The alternative is to wire the programmable stat into a real permanent
live. If it was a fresh install rather than an upgrade you'd then also
install a single channel timeswitch to handle the HW programming.
Most people seem to be installing these things as an upgrade, and hence
being misled about how to install them by the way a simple stat is
installed. Do the instructions not give guidance on this?
Cheers
IanC
Adam
<ian_c...@my-deja.com> wrote in message
news:3A0FE846...@my-deja.com...
>
>
> Tim Riglar wrote:
> >
> > The CM67 thermostat, for all it's clever features, is only a fancy
> > roomstat - it doesn't replace the controller.
>
> Hi Tim
>
> Although I don't have one I belive it does replace the controller.
> Usually the timing and temperature switching are in separate boxes, this
> being the programmer and simple room stat. These programable thermostats
> combine these into a single box, and take advantage of the integration
> to allow much more detailed programming.
The CM67 can be in one box (stat and timer) or two (timer and remote temp
sensor).
As being said it is not a fancy room stat. The optimiser version delays the
switch on of the boiler and it has a boiler ant-cycle feature.
Preferably it should not be switched via another conventional timer
(programmer). If it is, keep the programmer on 24 hours and let the CM67 do
the work.
Dave Liquorice
> ... also you need to make sure you still have an unblokced route from the
> boiler to the expansion pipe over the header tank.
This is the most important. Quite often to save a few feet of tube the feed
and expansion pipes are connected to the return and flow connections at the
cylinder not the boiler.
And agreed that to improve the system any further plumbing will have to be
undertaken. Still putting a room stat in may help quite considerably at
least there is some form of control then.
Tim Riglar
Well, first I have to come a bit clean and admit that I don't actually have
a CM67 either - I have a CM51 (not a conscious decision not to get the 67 -
just didn't find out about it), so everything I say could be wrong(!). The
CM51 is sold as a "Chronotherm" and the (minimalist) instructions that come
with it say "The chronotherm will work with other controls in your system to
provide comfortable temperatures in your home when you want them". The
original question from Menno seemed to imply that he wanted programmable
roomstat type functionality for the hot water, and he wanted to know if the
CM67 could do this. Clearly it can't in "normal" usage, but given that the
whole system is about switching 240V around, you could obviously wire the
whole thing up however you wanted, with any number of time, temperature and
control valves.
I would still maintain though, that the intended use for the CM67 is as a
simple replacement for the roomstat. The fact that the only sensible way of
using it is then to switch the controller to constant for the CH doesn't
matter - the controller would still be needed to time hot water cycles.
Agreed - if HW demand is not via the controller, then the CH controller side
becomes redundant with a programmable roomstat. Still doesn't change the
fact that the only way the roomstat can "turn off" the CH is by setting the
required temperature low, while the controller is able to switch off the
supply.
Having said all that - highly recommend a programmable roomstat for toasty
rooms when you want them ;--)
(Oops, sorry, bit longer ramble than I meant!)
Regards
Tim
<ian_c...@my-deja.com> wrote in message
news:3A0FE846...@my-deja.com...
>
>
> Tim Riglar wrote:
> >
> > The CM67 thermostat, for all it's clever features, is only a fancy
> > roomstat - it doesn't replace the controller.
>
> Hi Tim
>
> Although I don't have one I belive it does replace the controller.
> Usually the timing and temperature switching are in separate boxes, this
> being the programmer and simple room stat. These programable thermostats
> combine these into a single box, and take advantage of the integration
> to allow much more detailed programming.
>
Dave Liquorice
> The alternative is to wire the programmable stat into a real permanent
> live.
But then you also get CH on when the HW timer comes on as you have to
connect the switched live from the CM67 to both the pump and boiler. When
the HW circuit comes live it also powers the pump as the two lives are
connected together...
I haven't engaged brain enough to work out if the simple changeover in the
CM67 could be utilised to turn the pump off in the "CH off" state but still
allow power to pump and boiler in the "CH on" state.
I guess one could bung a relay or two in but that is getting complex.
Dave Liquorice
> Putting thermostat on the HW cylinder and a 2-port zone valve in the
> gravity HW loop ...
Making sure that the feed and expansion connections are not compromised...
ian_c...@my-deja.com
Dave Liquorice wrote:
>
> On Mon, 13 Nov 2000 13:10:30 +0000, ian_c...@my-deja.com wrote:
>
> > The alternative is to wire the programmable stat into a real permanent
> > live.
>
> But then you also get CH on when the HW timer comes on as you have to
> connect the switched live from the CM67 to both the pump and boiler. When
> the HW circuit comes live it also powers the pump as the two lives are
> connected together...
Hi Dave
When starting from where Menno is starting from that's true, and I
didn't mean to question it.
I maintain that the proper use for these things is in a system where CH
and HW are independent. Once you're in that position the wiring would be
sorted out to avoid the issue you mention. The micro-switch in the HW
valve for C-plan provides the electrical isolation between the boiler
and pump lives.
You could run into exactly the same issue if you bought any 16-mode
programmer when your plumbing only supports 10-mode.
Cheers
IanC
ian_c...@my-deja.com
Tim Riglar wrote:
>
> HI Adam
Ian actually, but I'm not offended.
> ...everything I say could be wrong(!).
We're even there then.
> The
> original question from Menno seemed to imply that he wanted programmable
> roomstat type functionality for the hot water, and he wanted to know if the
> CM67 could do this.
I suspect we're at crossed purposes. I'm not talking about HW control.
It would be unusual to want different HW temps throughout the day, and a
little difficult given the insulated thermal mass properties of a
typical HW cylinder. You'd normally be happy with a cylinder stat to
select the one temperature, and a timeswitch to specify the two or three
time periods you needed the water at that temperature.
As I understand it, its the preemptive, multi-temperature point nature
of the CM67 type thing which makes them attractive. I doubt that Menno
wanted that level of control over his HW temp, but could be wrong.
> the controller would still be needed to time hot water cycles.
A controller, certainly. As I said, in a fresh install that would be a
simple timeswitch and cylinder stat.
> Still doesn't change the
> fact that the only way the roomstat can "turn off" the CH is by setting the
> required temperature low, while the controller is able to switch off the
> supply.
OK. This is where I could be getting it completely wrong. I assume there
is an on/off switch of some kind. If not then I'm amazed. Its only mid
range and above [1] 'standard' controllers that will allow you to select
constant CH with timed HW. If there is no on/off on the CM67 then it
implies that if wired in to the old CH channel you'd have to be in the
fortunate position of having such a controller for it to really be able
to do its optimisation job. Menno for one isn't.
I don't think controls for anything should be counter intuitive, and so
I think putting these devices into their own circuit and having a simple
timeswitch for the HW is the 'right' thing to do. Otherwise someone
(future occupants?) will probably get confused. If the CM67 needs a
lightswitch type switch to be flipped at the start/end of the heating
season so be it. BTW, I do also realise that removing a perfectly
functional programmer just because it has a now redundant channel is not
a cost effective thing to do!
Cheers
IanC
[1] meaning 'If you look at a typical manufacturers programmer range
they'll go from timeswitch->mini-programmer->programmer->independent
programmer. Its only at the programmer point that the feature mentioned
appears.'
Menno
initially!
As Ian suggested, I am happy with the HW on just a timer, with the HW temp
controlled by a tank stat.
I just thought that the CM67 with it's amazingly (yes it is more than just a
normal stat) flexible 7-day, 6 different time-points per day programming,
with temperature settings at each time point ( with optimum start), would
also be able to do a simple task like send an on/off signal at certain times
for the HW. But it doesnt. Seems a gap in the market there tho. The only one
I could find, as suggested, was the Danfoss TP9 but it's not as flexible,
24hr or 5/2 day only, and doesnt come in a wirless RF option like the CM67 I
have.
But back to my problem, I have learned from this newsgroup that my best
options are to:
a) Just wire the CM67 in series with the current controller. Negative points:
This means the HW is always on if I want my CM67 controlling the CH 24hrs.
Also the HW temp is only controlled by the boiler stat. These are limitations
of my current system. To fix the latter I can do b), to fix both c) or d)
b) Add a tank stat which has 'common', 'heat needed', and 'satisfied'
connectors. I can get the CM67 controlling the CH, the old controller the HW.
Also this means the HW temp is now no longer controlled by the boiler stat,
and I can wire it so the CH can come on and fire up the boiler when HW doesnt
need heat. Negative points: HW temp will still rise to boiler temp when CH is
on.
c) Go for the Honeywell c plan. Requires a v4043H valve (btw what does that
number stand for?) and tank stat. I figured out how to wire this so the old
controller can control HW (sends signal to tank stat, and if that requires
heat, to the boiler and the valve opens) , and CM67 controls CH (signal to
the pump, and the boiler if HW isnt on). I know maybe I should get a HW
controller only to replace the old one, but it's maybe a waste of money.
Guess I just stick some tape over the bit I dont need, so I dont confuse
anyone else. Negative points: see below.
d) Go for one of the fully pumped plans described in the FAQ
So for economical and environmental purposes I should really forget a) and
b). c) sounds the easiest, but this involves plumbing, of which I have no
experience, apart from fitting an external tap kit from Focus Do it All :) So
this makes me think if I do get tools/skills to plumb (which I will probably
need anyway when I come to do the next project - new kitchen units) should I
go for d)?
What benefits do I get from fully pumped? All I could see from past ng
messages was that HW would be heated faster from cold, and that with c) when
HW is on I could get gravity circulation happening in the CH loop, if water
gets past the pump. I will check tonight to see how much of a problem this is
with my system. Anything else I should know?
Also I take it if I go for c) I should place the valve close to the tank, to
avoid heating unnecesarry pipework?
Again thanks for your help, I would be lost without it, and sorry for more
newbie questions.
Regards,
Menno
PS sorry if it rambles on a bit, but I wrote it already once and then the
browser crashed on me, loosing it all!
ian_c...@my-deja.com
Menno wrote:
> b) Add a tank stat which has 'common', 'heat needed', and 'satisfied'
> connectors. I can get the CM67 controlling the CH, the old controller the HW.
> Also this means the HW temp is now no longer controlled by the boiler stat,
> and I can wire it so the CH can come on and fire up the boiler when HW doesnt
> need heat. Negative points: HW temp will still rise to boiler temp when CH is
> on.
You will still need HW on constant for this to work. I think you relaise
that, but didn't explicity say it.
>
> c) Go for the Honeywell c plan. Requires a v4043H valve (btw what does that
> number stand for?) and tank stat.
4043 is just a part number. Actully its part of a part number. With 1056
on the end it has 22mm compression fittings, with 1007 it has imperial
unions. 4073s are the Y-plan valves, etc.
> What benefits do I get from fully pumped?
> All I could see from past ng
> messages was that HW would be heated faster from cold.
Probably. Do you ever run out of HW? I have an immersion boost on my
cylinder that I use a couple of times a month if we want to draw two
fresh baths in quick succession. That may be easier all around.
> Anything else I should know?
Well, if your gravity HW is on different boiler tappings to the CH
circuit then getting them onto a common pumped circuit may be harder
work than you imagine. You'd have to take care about which tappings you
kept in service, cap off the ones you weren't now using, etc. In any
case you'd need to tee into the circuit after the pump. In summary, the
ease depends on the current physical plumbing arrangement.
I'd stick with gravity HW and pumped CH. Go C-plan. If you do get
gravity circulation in the CH you can still fix it with a valve in the
CH circuit. Just take the wire that currently powers the pump to the
valve 'activate', and run the pump via a permanent live switched by the
'open now' and 'common' contacts on the valve microswitch.
> Also I take it if I go for c) I should place the valve close to the tank, to
> avoid heating unnecesarry pipework?
I don't think it really matters. Anywhere in the HW flow will have the
right effect. I'd go for somewhere with a bit of space around it, where
the valve won't be installed incorrectly (eg inverted) and that's
convenient for wiring purposes. Since the later point implies near the
tank stat then near the tank may be sensible.
Cheers
IanC
Dave Liquorice
> I maintain that the proper use for these things is in a system where CH
> and HW are independent.
Definately, looking hard at them myself for the house. Waiting to get some
decent bumpf on the Honeywell (filled in web page request on Sunday, their
site has no usefull information) to see how it compares against the Danfoss
TP75 (got data sheet, user and installation guides from the web).
The system here has 2 CH loops and 2 HW loops all independant, easy to one
of these to either heating loop. Mind you I think I'd still wire it into the
position of a normal room stat, that way I can turn the CH off without
having to fiddle with the program or go wandering around the building to
find it. The programmers are in the boiler room next to the kitchen. B-)
Menno
ian_c...@my-deja.com wrote:
> Probably. Do you ever run out of HW? I have an immersion boost on my
> cylinder that I use a couple of times a month if we want to draw two
> fresh baths in quick succession. That may be easier all around.
We dont run out of water at the moment as we take showers only. And we also
have an immersion boost on the cylinder, so that will help if we ever do.
> Well, if your gravity HW is on different boiler tappings to the CH
> circuit then getting them onto a common pumped circuit may be harder
> work than you imagine. You'd have to take care about which tappings you
> kept in service, cap off the ones you weren't now using, etc. In any
> case you'd need to tee into the circuit after the pump. In summary, the
> ease depends on the current physical plumbing arrangement.
>
> I'd stick with gravity HW and pumped CH. Go C-plan. If you do get
> gravity circulation in the CH you can still fix it with a valve in the
> CH circuit. Just take the wire that currently powers the pump to the
> valve 'activate', and run the pump via a permanent live switched by the
> 'open now' and 'common' contacts on the valve microswitch.
>
Yes, the gravity HW is on different tappings. It sounds like your right,
c-plan is the way to go.
Thanks,
Menno
Menno
"Dave Liquorice" <new...@howhill.com> wrote:
> Definately, looking hard at them myself for the house. Waiting to get some
> decent bumpf on the Honeywell (filled in web page request on Sunday, their
> site has no usefull information) to see how it compares against the Danfoss
> TP75 (got data sheet, user and installation guides from the web).
>
Yes the Honeywell site is not much use. I can fax or scan you the CM67 stuff
I got with mine if you like. Let me know, and I'll do so when I get to the
office tomorrow.
Cheers,
Malcolm Surgenor
>I don't have data on the CM67 (nothing useful on www.honeywell.com/uk)
>unlike the Danfoss site which has data sheets, user and installation
>instructions in .PDF format available for all their products, I digress.
Dave - can you point me in the right direction please. I couldn't find any of this on
their site.
Malcolm
Malcolm Surgenor
looking at danfoss-randall.
malcolm