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John
 
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Default No central heating - HW only threewayvalve and tank therm

I

As per my previous post, have now has a fiddle and got some more info -
yet I am still puzzled. My knowledge stops after gravity HW systems!

I am attempted to sort out a friends central heating (just moved house).
Their system has conventional boiler and programmer, cylinder thermostat and
three way value (Pipe in - and the Port A heating, Port B HW - Drayton
Flowmaster 2)

HW is OK

When Central heating is selected only HW heats - rads are completely cold -
pipe work in airing cupboard is red hot.

if I push the little lever on the 3way over from HW to CH (very hard to
pushover ) and hold it then the rads get warm - when I let go again the
valve
moves back to HW and the rads cool.

I am guessing that it is the motor on the valve? Is this right? Could it be
(or likely be) anything else? What would I need to test to find out?

If it is the motor? is this a standard part or does it depend on the valve?
(in this case Flowmaster 2)

Previous advised suggested that the motor had probably burned out and would
need replacing.

After removing the motor, and connecting directly to 240v I have found that
the motor works OK.

There is no room thermostat fitted. I have removed the cylinder thermostat,
which has three connections 1,3,4 according to info on the drayton site the
thermostat connects 1 to 3 untill it cuts out where it changes over to
connect 1 to 4

A test with the multimeter shows that 1 and 3 are connected, regardless of
the setting or hot hot the tank/therm is this does not change. It is
therefore certain that the therm needs replacing.

With the therm removed the heating does not work at all - When I connect 1
and 3 together (patch cable) the heating runs again (as you would expect).
The confusing part is that if I connect 1 and 4 together (as would happen if
the therm reached it set temp) nothing happens! In this case shouldnt the
heating run

I suspect that someone has had a fiddle before the house was sold - as the
therm was not fitted securely to the tank, screws missing and some of its
wiring connection looked a touch suspect

Can anyone help?



  #2   Report Post  
Roger Mills
 
Posts: n/a
Default No central heating - HW only threewayvalve and tank therm


"John" wrote in message
...
I

As per my previous post, have now has a fiddle and got some more info -
yet I am still puzzled. My knowledge stops after gravity HW systems!

I am attempted to sort out a friends central heating (just moved house).
Their system has conventional boiler and programmer, cylinder thermostat

and
three way value (Pipe in - and the Port A heating, Port B HW - Drayton
Flowmaster 2)

HW is OK

When Central heating is selected only HW heats - rads are completely

cold -
pipe work in airing cupboard is red hot.

if I push the little lever on the 3way over from HW to CH (very hard to
pushover ) and hold it then the rads get warm - when I let go again the
valve
moves back to HW and the rads cool.

I am guessing that it is the motor on the valve? Is this right? Could it

be
(or likely be) anything else? What would I need to test to find out?

If it is the motor? is this a standard part or does it depend on the

valve?
(in this case Flowmaster 2)

Previous advised suggested that the motor had probably burned out and

would
need replacing.

After removing the motor, and connecting directly to 240v I have found

that
the motor works OK.

There is no room thermostat fitted. I have removed the cylinder

thermostat,
which has three connections 1,3,4 according to info on the drayton site

the
thermostat connects 1 to 3 untill it cuts out where it changes over to
connect 1 to 4

A test with the multimeter shows that 1 and 3 are connected, regardless of
the setting or hot hot the tank/therm is this does not change. It is
therefore certain that the therm needs replacing.

With the therm removed the heating does not work at all - When I connect 1
and 3 together (patch cable) the heating runs again (as you would expect).
The confusing part is that if I connect 1 and 4 together (as would happen

if
the therm reached it set temp) nothing happens! In this case shouldnt the
heating run

I suspect that someone has had a fiddle before the house was sold - as the
therm was not fitted securely to the tank, screws missing and some of its
wiring connection looked a touch suspect

Can anyone help?




Sounds as if it may be wired incorrectly. Have a look at
http://www.diyfaq.org.uk/plumbing/pl...ml#midposition which may
shed some light on how it is supposed to work and on how it should be wired.

HTH,
Roger


  #3   Report Post  
John
 
Posts: n/a
Default No central heating - HW only threewayvalve and tank therm

Sounds as if it may be wired incorrectly. Have a look at
http://www.diyfaq.org.uk/plumbing/pl...ml#midposition which may
shed some light on how it is supposed to work and on how it should be

wired.

Thanks for the link - I was already suspecting that it was wired
incorrectly, quite how I sort out the mass of wiring Im not sure - looks
like a long test with the meter!

Any other suggestions, whilst I keep on reading?


  #4   Report Post  
Roger Mills
 
Posts: n/a
Default No central heating - HW only threewayvalve and tank therm


"John" wrote in message
...
Sounds as if it may be wired incorrectly. Have a look at
http://www.diyfaq.org.uk/plumbing/pl...ml#midposition which

may
shed some light on how it is supposed to work and on how it should be

wired.

Thanks for the link - I was already suspecting that it was wired
incorrectly, quite how I sort out the mass of wiring Im not sure - looks
like a long test with the meter!

Any other suggestions, whilst I keep on reading?



If you're lucky, all the components (boiler, pump, 3-port valve, programmer
and stats) will all be connected together via a 10-way junction box rather
than having joints all over the place. Do you have such as box?

If so, have a look at http://www.sunvic.co.uk/ and navigate to Product
Installation Literature, and click on the first wiring diagram link. This
should show you what should be connected to what.

Roger


  #5   Report Post  
Ed Sirett
 
Posts: n/a
Default No central heating - HW only threewayvalve and tank therm

John wrote:

I

As per my previous post, have now has a fiddle and got some more info -
yet I am still puzzled. My knowledge stops after gravity HW systems!

I am attempted to sort out a friends central heating (just moved house).
Their system has conventional boiler and programmer, cylinder thermostat and
three way value (Pipe in - and the Port A heating, Port B HW - Drayton
Flowmaster 2)

HW is OK

When Central heating is selected only HW heats - rads are completely cold -
pipe work in airing cupboard is red hot.

if I push the little lever on the 3way over from HW to CH (very hard to
pushover ) and hold it then the rads get warm - when I let go again the
valve
moves back to HW and the rads cool.

I am guessing that it is the motor on the valve? Is this right? Could it be
(or likely be) anything else? What would I need to test to find out?

If it is the motor? is this a standard part or does it depend on the valve?
(in this case Flowmaster 2)

Previous advised suggested that the motor had probably burned out and would
need replacing.

After removing the motor, and connecting directly to 240v I have found that
the motor works OK.

There is no room thermostat fitted. I have removed the cylinder thermostat,
which has three connections 1,3,4 according to info on the drayton site the
thermostat connects 1 to 3 untill it cuts out where it changes over to
connect 1 to 4

A test with the multimeter shows that 1 and 3 are connected, regardless of
the setting or hot hot the tank/therm is this does not change. It is
therefore certain that the therm needs replacing.

With the therm removed the heating does not work at all - When I connect 1
and 3 together (patch cable) the heating runs again (as you would expect).
The confusing part is that if I connect 1 and 4 together (as would happen if
the therm reached it set temp) nothing happens! In this case shouldnt the
heating run

I suspect that someone has had a fiddle before the house was sold - as the
therm was not fitted securely to the tank, screws missing and some of its
wiring connection looked a touch suspect

Can anyone help?


The main FAQ contains the help you need. You should probably add a room
thermostat
and replace any bits that don't work.
Looks like most of the bits are fine. just need to be wired up right.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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


  #6   Report Post  
John
 
Posts: n/a
Default No central heating - HW only threewayvalve and tank therm

If you're lucky, all the components (boiler, pump, 3-port valve,
programmer
and stats) will all be connected together via a 10-way junction box rather
than having joints all over the place. Do you have such as box?


There is a double socket back box with a blanking plate containig a 10 way
terminal block strip with the cables running into it. Looks a bit of a
jungle (and fitting tight behind the plumbing) but is a start.


If so, have a look at http://www.sunvic.co.uk/ and navigate to Product
Installation Literature, and click on the first wiring diagram link. This
should show you what should be connected to what.


thanks for the link


  #7   Report Post  
John
 
Posts: n/a
Default No central heating - HW only threewayvalve and tank therm

The main FAQ contains the help you need. You should probably add a room
thermostat
and replace any bits that don't work.
Looks like most of the bits are fine. just need to be wired up right.


Thanks for the link.

Printed off the FAQ info and will take it up with me tomorrow.I have already
recommened that a new programmer and room thermostat are fitted to the
system

The cylinder thermostat will def need replacing, but I just cant understand
why someone would fiddled with the connections and ended up wiring it up
wrongly!

Im sure that I have the info now to sort it out.
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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



  #8   Report Post  
Roger Mills
 
Posts: n/a
Default No central heating - HW only threewayvalve and tank therm


"John" wrote in message
...

The cylinder thermostat will def need replacing, but I just cant

understand
why someone would fiddled with the connections and ended up wiring it up
wrongly!



If their ambition exceeded their ability, they may well have thought that
they could fix the problem by changing the wiring. [i.e. they could have
confused component failure with incorrect wiring and could have tried to
"correct" it!]

Roger


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