Triport Valve Issue

[conoral11]

Hello there,

We've recently purchased our first home, and I have been updating the controls for the Central Heating / Hot Water.

Our original programmer/timer was the SwitchMaster 400, that allowed [Hot Water] or [Hot water + Central Heating].

We wanted to be able to control these individually and so purchased a Drayton LP722, which is now fitted and working.

However, When the Central Heating is signalled (without hot water) the boiler doesn't switch on.

I've traced this to the HSA3B triport valve that we have.

When Central heating is requested, the motor moves ALMOST all the way, just before the micro switch is activated inside the valve.

If you use the manual over-ride lever, and move it 1mm at most, the heating switches on as expected.

The actuator looks new, I've stripped it down and confirmed the switches operate cleanly, the gears are in good health, the spring is strong and all electrical connections are solid.

I can move the valve manually by hand without tools as well.

Is it likely the motor has given up its ghost? Or might there be problems with the valve as it will have not been used in a Central Heating only position from when ever it was fitted before we moved in?

Thanks in advance,

Conoral11

 

[jeff the gasman]

If you have voltage to the white wire but not the grey that is more than likely your problem.
The grey wire is hot water off/satisfied and is sent from the programmer or the cylinder thermostat.

 

[Echo the husky]

The Switchmaster 400 doesn't have a hot water off signal, so that wire won't have been connected. You will need to alter the wiring to follow the standard Y plan wiring diagram if you want separate heating and hot water, as long as your valve actuator is the HSA3 with a striped brown/white wire. The HSA3B is the number for the brass body.

 

[conoral11]

Jeff,

Thanks for the reply.

The valve only has 4 wires,

* Blue
* Brown/White
* Grey
* Orange

The connections on the back of the progammer also only had the following:

Live,
Neutral,
Central Heating ON
Hot Water ON

So no Heating off connection.

 

[Echo the husky]

Your valve has the correct number of wires. As Jeff says you need to connect HW off from your new programmer to the grey wire to get separate heating and hot water. If there is no spare wires etc and you can't/don't want to convert. You will need to set the programmer to gravity mode so hot water is automatically switched on when the heating is.

 

[jeff the gasman]

Long time since I saw a Switchmaster. London, 1988 ish.
As Freddo says.

 

[Echo the husky]

Long time since I saw a Switchmaster. London, 1988 ish.

Good grief that was the year I was born!

 

[conoral11]

Right,

Having re-read the datasheet along with your comments...

Do I disconnect the CH ON from the programmer, and instead connect that to HW Off?

At the moment I have connected:

* Neutral
* Live
* HW ON
* CH ON

After the switch:

* Neutral
* Live
* HW ON
* HW OFF

Will that then make sense?

P.S, the house was built in 88 and has had NO upgrades since.

 

[jeff the gasman]

Long time since I saw a Switchmaster. London, 1988 ish.

Good grief that was the year I was born!

You are young boy aren't you! Would you like a sweetie off uncle Jeff?
I'm nearly 60 and a pervert.

 

[Echo the husky]

No you need a new extra wire from HW off to grey on the valve.

Live
Neutral
Hot water off
Hot water on
Heating on

 

[conoral11]

Is that the cyclinder thermostat you are talking about?

 

[Echo the husky]

No I made a mistake and was too slow to correct it. I meant valve.

 

[conoral11]

Doesn't that mean that Heating on and hotwater off would then be connected?

From That Datasheet

4 wire Valve:
Blue (N)
Brown-white (HTG Call)
Orange (HWS Call)
Grey (HWS Sat)

 

[conoral11]

Ah,

Think I get it, if this diagram is correct:

 

[Echo the husky]

That's right,
When heating call and hot water satisfied signals are both on, the valve moves right over to heating only.
With no power at all (to heating call or hot water satisfied) the valve spring returns to hot water only.
With power on the heating call the valve moves to mid position heating and hot water.