drayton mid position actuator valve

[mrhappy61]

i had a new 2 way drayton valve fitted , for some reason it does not seem to ingauge fully to allow the hot water to circulate to the central heating, i unclip the electric box and turn the valve manually then the water circulates, so the mechanisium is ok but the main electrical box seems as though its working fine, there is also a loud buzzing noise from the unit and it get very hot and seems to smell as though the unit is over heating especially at night when it been on for a couple of hours. but the unit is brand new, any ideas alex

 

[ChrisR]

SOunds as though it must be faulty

 

[MANDATE]

If it's a new valve it shouldn't be faulty, so I would first establish if the valve is fitted the correct way round, then verify the wiring is correct.
There's plenty of posts on mid position valves which may help, most of my recent replies are related. so you can look at those.
Pay particular attention to the wire from the HW OFF terminal on the programmer to the grey of the valve. It seems lots of problems relate to this wire being omitted.

 

[need4speed]

Hi everyone.

I know this is an old topic, but I was wondering if anyone could help.
I've recently replaced a switchmaster valve (mid position) and actuator which had failed for a Drayton MA1 based on the advice I've seen on the forums. I have a gravity fed system, with a Switchmaster SM400 central heating timer control connected to this.

The Switchmaster had six cables and the Drayton MA1 has five. I've again used information posted on these forums, and used a junction box to connect the cables from the programmer to the new Drayton Actuator using the following method:

1. I cut off the lead to the switchmaster. On the switchmaster lead from the wiring cente i connected all the wires to a junction box.
2. I connected the orange and red together. Then joined this to the orange of the new valve.
3. I connected the yellow of the switchmaster lead to the white on the new valve.
4. I connected the white of the switchmaster lead to the grey of the new valve.
5. Finally I connected the blue to blue and earth to earth

However, when I powered everything back up, the valve stays in the Mid position, and doesn't move if I switch over to central heating&water or hot water only.

If i remove the actuator and watch it as i switch between central heating&hotwater and hot water only (on the pogramming control unit) the actuator is not moving. The valve itself moves freely by hand.

At first I thought i had a faulty actuator, so I went back to the supplier and they changed it, but the new one does exactly the same thing.

Could you or anyone else advise? I'd be most grateful.

 

[MANDATE]

Can only assume its not wired up correctly.
I also assume you can identify the three terminals on the programmer that controls the HW and CH. or the wires from them.
These are HW ON...........HW OFF........CH....ON

If you start with HW ON the wire may go through terminal box,but will go to the common terminal of the cylinder stat.
Cylinder stat has two output terminals (a) (not satisfied) and (b)(satisfied)
Wire from (a) supplies power to boiler/pump until it becomes satisfied.
Wire from (b) supplies power to the grey wire of valve.

Moving to the CH..ON wire, this supplies power to the room stat, then from the room stat to the white wire of the valve

When both HW and CH are selected the valve moves to mid position due to the white wire being live and grey not live.
When HW becomes satisfied, the grey becomes live by (b) above and sends the valve beyond mid point.
The boiler actually stops because cylinder stat has cut off the power, but this is restored when a micro switch in the valve is triggered and allows power out from the valves orange wire to power the boiler/pump.
So obviously this orange wire must also join up to (a) from cylinder stat.

The only problem with the above is that it relies on the HW being satisfied but what if the HW was not switched on. there is no power at the cylinder stat to divert.

This where a wire comes from the HW OFF terminal of the programmer and this leads to the grey wire of the valve or (b).

Obviously cylinder and room stats and motorised valve have cables already supplied and a terminal box is needed in order to join them.

There will of course also be neutral wires (blue) and earths (green/yellow) that will need joining.

I'm sure you can find all the above in the wiring diagram for the 'Y' plan on the honeywell site.
Hope it helps

 

[need4speed]

Mandate, thanks very much for your reply.

I'm not expert so I can't confess to following everything you said, but understand the basics of what you are saying.

From the programmer I have 4 terminals labelled - N (two blue cables), L (one red cable), 1 (Heating on, Red cable again) 2 - not connected, 3 (Hot water on, Brown cable), 4 (Heating off, no cable)

I assume these are all correct, they haven't been modified in any way, and everything was working prior to the issue with the actuator.[/img]

 

[MANDATE]

Are you sure 4 is heating off.
For mid position to function correctly you need.

HW ON wire to feed cylinder stat and then boiler

CH ON wire to feed room stat and then white wire of valve

HW OFF wire to feed the grey wire of valve (this is required when the HW is not switched on.

 

[need4speed]

Hi Mandate,

as fae as i am aware, yes this is correct. Please see my enclosed screenshots:

http://www.diynot.com/network/need4speed/albums/

 

[MANDATE]

I don't know how your programmer was wired before, but a wire from HW OFF terminal to the grey of the valve is needed.
You don't have a HW OFF terminal and I suspect it is not the correct programmer.
I have established there are programmers sm1 and sm2 and sm2 does have the HW OFF terminal while sm1 does not.

www.draytoncontrols.co.uk/WorkArea/DownloadAsset.aspx?i.

 

[need4speed]

Mandate,

thanks once again for your help.

I appear to have resolved the issue.

The instructions that come with the drayton ma1 tell us that the manual lever is automatically released when the valve is powered on. So I've always left it in this position and stupidly assumed this to be correct. So I just tried releasing the manual lever and everything appears to be ok now.

I am happy to say the wiring in the junction box is ok, and valve/acutuator responds and opens the correct way depending on whether I select hot water only or Central Heating & Hotwater.

So I apologise for wasting you're time as well as my own, checking wiring and diagrams etc. I really do appreciate your advice and time.

Kind Regards

Need4Speed.