i'm fitting a home style heating and water system to my motorhome, a 12 volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot water
cylinder with an extra coil to heat from the engine) 3 radiators, digital
programmer, tank and room stats, and hopefully a 3 way valve to select hot
water, heating or both to be heater when the boilers running.

But i just can't seem to find a 12 volt DC powered 3 way valve, the mid
position type that's fitted to 99% of home central heating systems,

does anyone know where i can get one from?

and i know all about inverters, and that's not an option to run a simple
valve, as it'd have to be powered all the time, and my 2 inverters in the
van pull a fair bit of current when ideling, and take a few seconds to power
up due to self checks (ones a 1600 watt modified sine wave that powers the
microwave, central vacuum system and any phone chargers etc, that high a
power uses about an amp when no load is being pulled, the others a 300 watt
pure sine wave inverter that powers only the washing machine, being pure
sine wave it pulls even more power than the big inverter when left powered
up and not being used, and takes about 10 seconds to turn on due to complex
self checks of the entire system)

So i really need a 12 volt powered 3 way valve, but where are they hiding???

CampinGazz used his keyboard to write :
i'm fitting a home style heating and water system to my motorhome, a 12 volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot water
cylinder with an extra coil to heat from the engine) 3 radiators, digital
programmer, tank and room stats, and hopefully a 3 way valve to select hot
water, heating or both to be heater when the boilers running.

12v 5Kw sounds to be rather a large supply cable (?)


But i just can't seem to find a 12 volt DC powered 3 way valve, the mid
position type that's fitted to 99% of home central heating systems,

You might have better luck finding a pair of simple 12v solenoid valves
instead of the three port.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Harry Bloomfield" wrote in message
...
CampinGazz used his keyboard to write :
i'm fitting a home style heating and water system to my motorhome, a 12
volt eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot
water cylinder with an extra coil to heat from the engine) 3 radiators,
digital programmer, tank and room stats, and hopefully a 3 way valve to
select hot water, heating or both to be heater when the boilers running.

12v 5Kw sounds to be rather a large supply cable (?)

That is waht I thought at first, 416A is rather large!
I expect he means it is a gas boiler (LPG) with 12v controls though..


Sparks...

"Sparks" wrote in message
...

"Harry Bloomfield" wrote in message
...
CampinGazz used his keyboard to write :
i'm fitting a home style heating and water system to my motorhome, a 12
volt eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot
water cylinder with an extra coil to heat from the engine) 3 radiators,
digital programmer, tank and room stats, and hopefully a 3 way valve to
select hot water, heating or both to be heater when the boilers running.

12v 5Kw sounds to be rather a large supply cable (?)

That is waht I thought at first, 416A is rather large!
I expect he means it is a gas boiler (LPG) with 12v controls though..

yes, it's 5KW heat output, powered by diesel, the 12 volts runs the
combustion blower fan, controls and water pump,

On Wed, 01 Mar 2006 10:36:59 GMT, Harry Bloomfield
wrote:

CampinGazz used his keyboard to write :
i'm fitting a home style heating and water system to my motorhome, a 12 volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot water
cylinder with an extra coil to heat from the engine) 3 radiators, digital
programmer, tank and room stats, and hopefully a 3 way valve to select hot
water, heating or both to be heater when the boilers running.

12v 5Kw sounds to be rather a large supply cable (?)

eberspacher = diesel or petrol or lpg fuelled, NOT 12v! Commonly used
by truckers and yachties.




--

On Wed, 1 Mar 2006 09:49:40 -0000, "CampinGazz" wrote:

i'm fitting a home style heating and water system to my motorhome, a 12 volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot water
cylinder with an extra coil to heat from the engine) 3 radiators, digital
programmer, tank and room stats, and hopefully a 3 way valve to select hot
water, heating or both to be heater when the boilers running.

But i just can't seem to find a 12 volt DC powered 3 way valve, the mid
position type that's fitted to 99% of home central heating systems,

Perhaps they are used on boats? Worth trying a chandlery.

sponix

CampinGazz wrote in message
...
i'm fitting a home style heating and water system to my motorhome, a 12
volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot water
cylinder with an extra coil to heat from the engine) 3 radiators, digital
programmer, tank and room stats, and hopefully a 3 way valve to select hot
water, heating or both to be heater when the boilers running.

But i just can't seem to find a 12 volt DC powered 3 way valve, the mid
position type that's fitted to 99% of home central heating systems,

does anyone know where i can get one from?


Don't think you can get these,
Im pretty sure my BIL Winnebago thing uses two 12v 2way (On/Off) solenoid
type valves to control the CH/HW.
And S-plan plumbing
http://content.honeywell.com/uk/home...s.htm#S%20Plan




-

"Mark" wrote in message
...

CampinGazz wrote in message
...
i'm fitting a home style heating and water system to my motorhome, a 12
volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot water
cylinder with an extra coil to heat from the engine) 3 radiators, digital
programmer, tank and room stats, and hopefully a 3 way valve to select
hot
water, heating or both to be heater when the boilers running.

But i just can't seem to find a 12 volt DC powered 3 way valve, the mid
position type that's fitted to 99% of home central heating systems,

does anyone know where i can get one from?


Don't think you can get these,

I suspect you are correct. The "normal" three way valves as used in CH
systems are stalled in some positions and this is easier to achieve with the
AC synchronous motors with which they are fitted. I think this sort of
operation would be a lot harder to achieve with a 12V DC motor, which is
probably why you can't find them. As another poster has suggested, the use
of 2 12V solenoid valves and appropriate controls would be a better bet,
although this arrangement could fail with all shut (which a 3-way valve
can't) giving rise to potential hazards. It might be better to employ one
solenoid valve and put up with the much less flexible options of "Water
only" and "Heating and water", putting up with the lower flow round the
heating circuit (but it's only three rads). There is always a water path
open whatever valve failure scenario occurs.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

Bob Mannix wrote in message

"Mark" wrote in message
i'm fitting a home style heating and water system to my motorhome, a 12
volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot
water
cylinder with an extra coil to heat from the engine) 3 radiators,
digital
programmer, tank and room stats, and hopefully a 3 way valve to select
hot
water, heating or both to be heater when the boilers running.

But i just can't seem to find a 12 volt DC powered 3 way valve, the mid
position type that's fitted to 99% of home central heating systems,

does anyone know where i can get one from?


Don't think you can get these,

I suspect you are correct. The "normal" three way valves as used in CH
systems are stalled in some positions and this is easier to achieve with
the
AC synchronous motors with which they are fitted. I think this sort of
operation would be a lot harder to achieve with a 12V DC motor, which is
probably why you can't find them. As another poster has suggested, the use
of 2 12V solenoid valves and appropriate controls would be a better bet,
although this arrangement could fail with all shut (which a 3-way valve
can't) giving rise to potential hazards.

I *Think* on the Winnebago one valve is N/O (HW) and the other is N/C
On energising they switch state, so even with power off there is always a
water path
open.




-

In an earlier contribution to this discussion,
CampinGazz wrote:

i'm fitting a home style heating and water system to my motorhome, a
12 volt eberspacher 5KW water boiler, a 20 litre twin coil calorifier
(hot water cylinder with an extra coil to heat from the engine) 3
radiators, digital programmer, tank and room stats, and hopefully a 3
way valve to select hot water, heating or both to be heater when the
boilers running.
But i just can't seem to find a 12 volt DC powered 3 way valve, the
mid position type that's fitted to 99% of home central heating
systems,

You'd probably stand more chance of getting 12v on/off valves - rather than
a 3-port valve - and then use 2 of them, as in a domestic S-Plan rather than
Y-plan system. I don't know about secondary contacts which close when the
valves open - you may need to use relays to create that feature.
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but is disposable in the event of excessive
spam.

"Mark" wrote in message
...

Bob Mannix wrote in message

"Mark" wrote in message
i'm fitting a home style heating and water system to my motorhome, a
12
volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot
water
cylinder with an extra coil to heat from the engine) 3 radiators,
digital
programmer, tank and room stats, and hopefully a 3 way valve to select
hot
water, heating or both to be heater when the boilers running.

But i just can't seem to find a 12 volt DC powered 3 way valve, the
mid
position type that's fitted to 99% of home central heating systems,

does anyone know where i can get one from?


Don't think you can get these,

I suspect you are correct. The "normal" three way valves as used in CH
systems are stalled in some positions and this is easier to achieve with
the
AC synchronous motors with which they are fitted. I think this sort of
operation would be a lot harder to achieve with a 12V DC motor, which is
probably why you can't find them. As another poster has suggested, the
use
of 2 12V solenoid valves and appropriate controls would be a better bet,
although this arrangement could fail with all shut (which a 3-way valve
can't) giving rise to potential hazards.

I *Think* on the Winnebago one valve is N/O (HW) and the other is N/C
On energising they switch state, so even with power off there is always a
water path
open.

True, but that is only one failure mode. It's still possible for a single
stick shut to result in no water path. It is physically impossible in a 3
way valve.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

"Mark" wrote in message
...

Bob Mannix wrote in message

"Mark" wrote in message
i'm fitting a home style heating and water system to my motorhome, a
12
volt
eberspacher 5KW water boiler, a 20 litre twin coil calorifier (hot
water
cylinder with an extra coil to heat from the engine) 3 radiators,
digital
programmer, tank and room stats, and hopefully a 3 way valve to select
hot
water, heating or both to be heater when the boilers running.

But i just can't seem to find a 12 volt DC powered 3 way valve, the
mid
position type that's fitted to 99% of home central heating systems,

does anyone know where i can get one from?


Don't think you can get these,

I suspect you are correct. The "normal" three way valves as used in CH
systems are stalled in some positions and this is easier to achieve with
the
AC synchronous motors with which they are fitted. I think this sort of
operation would be a lot harder to achieve with a 12V DC motor, which is
probably why you can't find them. As another poster has suggested, the
use
of 2 12V solenoid valves and appropriate controls would be a better bet,
although this arrangement could fail with all shut (which a 3-way valve
can't) giving rise to potential hazards.

I *Think* on the Winnebago one valve is N/O (HW) and the other is N/C
On energising they switch state, so even with power off there is always a
water path
open.

You can get 12v valves like this too :-)

Sparks...

Sparks wrote in message


You can get 12v valves like this too :-)

Sparks...

If you get an irritable urge to hit the Follow-up button at least read the
rest of the thread first.
Its 12v that we are talking about !



-

"Mark" wrote in message
...

Sparks wrote in message


You can get 12v valves like this too :-)

Sparks...

If you get an irritable urge to hit the Follow-up button at least read the
rest of the thread first.
Its 12v that we are talking about !

I did, maybe you should do so.

The last poster said he *thought* this was the case - I have used 12v N/O
and N/C valves, so I know they do exist, and are easily obtainable here in
the UK.

Sparks...

"Sparks" wrote in message
...

"Mark" wrote in message
...

Sparks wrote in message


You can get 12v valves like this too :-)

Sparks...

If you get an irritable urge to hit the Follow-up button at least read
the
rest of the thread first.
Its 12v that we are talking about !

I did, maybe you should do so.

The last poster said he *thought* this was the case - I have used 12v N/O
and N/C valves, so I know they do exist, and are easily obtainable here in
the UK.

can you give me a pointer to them please??

they need to be able to work with 82 degree C water going through them all
the time, be continious rated, and not cost the earth... seems i can get
what i want for a few hundered quid, or some that dont say they are rated
for hot water for 15 quid,

The last poster said he *thought* this was the case - I have used 12v N/O
and N/C valves, so I know they do exist, and are easily obtainable here
in the UK.

can you give me a pointer to them please??

they need to be able to work with 82 degree C water going through them all
the time, be continious rated, and not cost the earth... seems i can get
what i want for a few hundered quid, or some that dont say they are rated
for hot water for 15 quid,

I bought some from http://www.betavalve.com/ - I just called them and they
were able to supply me with small quantities (for order was for 1, to see if
it was what I needed)

Sparks...

On Wed, 1 Mar 2006 14:52:08 -0000, "Bob Mannix"
wrote:

I think this sort of
operation would be a lot harder to achieve with a 12V DC motor, which is
probably why you can't find them. As another poster has suggested, the
use
of 2 12V solenoid valves and appropriate controls would be a better bet,
although this arrangement could fail with all shut (which a 3-way valve
can't) giving rise to potential hazards.

I *Think* on the Winnebago one valve is N/O (HW) and the other is N/C
On energising they switch state, so even with power off there is always a
water path
open.

True, but that is only one failure mode. It's still possible for a single
stick shut to result in no water path. It is physically impossible in a 3
way valve.

Don't forget that there is Honeywell S-plan. This consists of two
port valves, with one normally being open at a time.

A microswitch in each is used in the path to fire the boiler such that
unless at least one valve is open, the boiler can't fire.

Whether this exists for 12v valves, I am less certain, however a look
through the web site of Sauter may reveal something suitable.

http://www.sauter-controls.com/pds/pds/indexe.html

Their products are orderable through PlumbCenter or ClimateCenter


--

..andy

On Wed, 1 Mar 2006 14:37:41 -0000, "Roger Mills \(aka Set Square\)"
wrote:

In an earlier contribution to this discussion,
CampinGazz wrote:

i'm fitting a home style heating and water system to my motorhome, a
12 volt eberspacher 5KW water boiler, a 20 litre twin coil calorifier
(hot water cylinder with an extra coil to heat from the engine) 3
radiators, digital programmer, tank and room stats, and hopefully a 3
way valve to select hot water, heating or both to be heater when the
boilers running.
But i just can't seem to find a 12 volt DC powered 3 way valve, the
mid position type that's fitted to 99% of home central heating
systems,

You'd probably stand more chance of getting 12v on/off valves - rather than
a 3-port valve - and then use 2 of them, as in a domestic S-Plan rather than
Y-plan system. I don't know about secondary contacts which close when the
valves open - you may need to use relays to create that feature.


Even so, this is not quite as foolproof as two port S-plan valves
because the latter have a mechanically linked microswitch which can
only operate if the valve really is open; I suppose unless the
contacts weld shut or something.

With a relay across the coil of a solenoid valve, you don't know if
the valve coil is open circuit or the valve stuck.

Presumably a boiler should protect itself in case of pump failure so
one would hope that it doesn't all go bang or I suppose another way
would be to include a flow switch and use that to control the
boiler.... That would be fail safe at least (unless its contacts
welded shut of course.)





--

..andy

In an earlier contribution to this discussion,
Andy Hall wrote:


You'd probably stand more chance of getting 12v on/off valves -
rather than a 3-port valve - and then use 2 of them, as in a
domestic S-Plan rather than Y-plan system. I don't know about
secondary contacts which close when the valves open - you may need
to use relays to create that feature.


Even so, this is not quite as foolproof as two port S-plan valves
because the latter have a mechanically linked microswitch which can
only operate if the valve really is open; I suppose unless the
contacts weld shut or something.

I was aware that it's not as good as a valve with built-in microswitches,
and should perhaps have made that limitation more explicit. Possibly the
heating system in a motorhome is left unattended less than that in domestic
premises - so you would quickly become aware of a problem - I don't know.

You could always plumb an automatic by-pass valve in parallel with the
heating valve - which would open in the event of the boiler/pump running
when both valves were closed.
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but is disposable in the event of excessive
spam.

"Roger Mills (aka Set Square)" wrote in message
...
In an earlier contribution to this discussion,
Andy Hall wrote:


You'd probably stand more chance of getting 12v on/off valves -
rather than a 3-port valve - and then use 2 of them, as in a
domestic S-Plan rather than Y-plan system. I don't know about
secondary contacts which close when the valves open - you may need
to use relays to create that feature.


Even so, this is not quite as foolproof as two port S-plan valves
because the latter have a mechanically linked microswitch which can
only operate if the valve really is open; I suppose unless the
contacts weld shut or something.

yup, the eberspacher heater is full of safety devises, i'd imagine the pump
would stall or run slow if it had no where to pump the water, and the heater
shuts down and flashes a fault code if the pump runs at a lower speed than
it should because it thinks there's a blockage.

it's also got an overheat protection of about 95 degrees C, where it shuts
down again and won't re-start untill the fault code is cleared and hopefully
the fault is rectified as well.. otherwise it'll just shut down again, 3
shut downs and it locks out needing a reset with the programmer.

of course all this computer control means there's more to go wrong in the
first place with all these sensors, but at least it's got plenty of safety
things.

In an earlier contribution to this discussion,
Aidan wrote:

Sunvic (& I
think Danfoss) valves are wired as motor open-motor closed (mo-mo) so
they only use power whilst moving (assuming they're not spring
return).

No - Danfoss 3-port valves are spring return, and the motor continuously
runs stalled in the mid and CH positions.
--
Cheers,
Roger
______
Please reply to newsgroup.
Reply address IS valid, but is disposable in the event of excessive
spam.

"Aidan" wrote in message
oups.com...


You might find it simpler to use 2 x 12 V dc centrifugal pumps with
non-return valves on the returns.
-----

you know what, you might have cracked it,

the eberspacher has one pump already, i can get another one pretty easily, i
just have to check where the flow controll thing is in the heater, i dont
think it's the pump motor, afaik it's just 2 wires, + and - 12 v, powered
whne the heaters operating, and also powered when the heater goes into stand
by mode.... i.e. main power on, but the temp has reached and stayed at or
above 82 degrees for more than 5 minutes,

There is an eberspacher timer unit for this heater, it gives 3 operating
times a day, and what i was thinking....

Have a thermostat straped to the calorifier just like a domestic hot water
tank does, it's just a basic switch after all isnt it.

use the eberspacher digital timer unit, and have it set for 3 x 25 minute
operating times throughout the day, have the power to the heater start up
circuit go through the tank stat (via a relay if needed etc)
so if at one of the 25 mintue cycles the tank stat if on, the eberspacher
fires up and heats the tank of water up, shutting down after it's reached 82
degrees C for 5 minutes as above, or when the time peroiod expires,

If the tank stat is open when a time period is active, nowt happens, the
tank's still hot (apparantly a small calorifier can keep it's heat for 24
hours, and only needs 20 minutes to bring the water upto temp from cold..
that's based on much larger tanks than i'll be using, so i'd get faster heat
up temps)

there'd be 2 pumps as suggested with non return valves etc, and a relay to
select which pump operates, normaly closed contacts allow the 1st pump to
operate when the calorifier wants heating.. i.e. pump selector relay is not
energised.

Then for the heating side, i dont really need times for that, as when it's
cold i'll put it on, there'll be thermostatic rad valves to regulate the
temp in the different areas of the van (living area, bathroom etc)

So when i want heating, i turn a switch on, which is connected through a
room stat, if the van's cold enough according to the room stat, power is
sent down the heater start up wire bypassing the timer (may need to use a
relay to avoid backfeeding the timer, not sure if it'll throw a wobbely and
bring up a fault code.. unauthorized heater usage or something
and it'll also switch the relay on the pumps to power pump 2 when the heater
calls for the water to circulate.

So the eberspacher heats the water up, pump 2 pumps it around the radiators
untill the room stat shuts it off, the water going through the heater is at
82*C for 5 mins, or i turn it off manualy.

I could think of a way to make pump 1 operate at the same time if needed by
the tank stat and timer being on i guess. thus doing the same as a 3 way mid
position valve does, but with 12 volts DC... and a lot more complications.

does the above sound feesable? any input welcome, as i don't know that much
about centeral heating systems.

on boats where these heaters are usually used, they all seem happy to have a
manual valve they select hot water or heating with, but i like things to be
automatic, the stand alone water heater i had was, as was the gas fired
blown air heating system,
i'm just combining 2 units into one, and heating with hot water now, but i
want a better system than i had before, ie. one fuel source, one unit, and
hopefully easier use, tho that may be pushing it.

Roger Mills (aka Set Square) wrote:

No - Danfoss 3-port valves are spring return

Yes, they are. So some of the Sunvic 2-port actuators are mo-mo.

and the motor continuously
runs stalled in the mid and CH positions.

I meant the 2-port valves. The spring return to closed on power failure
is a safety feature in some installations, so the OP would have to
devise a safe installation if he went for the motorized valves.

CampinGazz wrote:

Now I come to think of it, you can get actuators for small valves with
'wax motor' or 'thermo-hydraulic' actuators, which work on DC voltages
but they're generally 24V AC/DC. I think they're similar to
thermostatic rad valves with an added electric resistance heater to
achieve the electric control.

Danfoss Randall, Siemens, etc., do them in the UK. They're usually
used on radiator valves but will operate a small valve for DHWS just as
well. I don't know how the electric consumption compares with motorized
valves, as this might be an issue.